Search

Background Because nearly one-third of births in the United States are now delivered by cesarean—more than 1.27 million women each year—national organizations have recently published revised guidelines for the management of labor. These new guidelines stipulate that labor arrest should not be diagnosed unless ≥ 6 cm cervical dilatation had been reached or labor had been stimulated for at least 6 hours. Objective To determine the cervical dilatation and hours of labor stimulation prior to cesarean delivery for arrest of dilatation. Study Design Between 1 January 1999 and 31 December 2000, a prospective observational study of all primary cesarean deliveries was conducted at 13 university centers comprising the Eunice Kennedy Shriver National Institute for Child Health and Human Development, Maternal-Fetal Medicine Units Network. This secondary analysis includes all liveborn, singleton, non-anomalous, cephalic gestations delivered by primary cesarean at ≥ 37 weeks. A cesarean was considered to have been performed for arrest of dilatation if the indication for the procedure was failure to progress, cephalopelvic disproportion, or failed induction. Augmentation was defined as stimulation after spontaneous labor had been previously diagnosed. Analysis included both the latent and active phases of labor. The active phase of labor was diagnosed when cervical dilatation was ≥ 4 cm in the presence of uterine contractions. Results A total of 13,269 primary cesareans were available for analysis and 8,546 (65%) were performed for inadequate progress of labor with cervical dilatation recorded at the time of cesarean. Of these cesareans for labor arrest, a total of 719 (8%) were performed in the latent phase of labor and 7827 (92%) were performed when cervical dilatation was ≥ 4 cm (active phase). Approximately two-thirds (N=5876; 69%) received intrauterine pressure monitoring. A total of 5636 women (66% of those reaching the active phase of labor) had reached 6 cm or more cervical dilatation before cesarean was performed. Moreover, a total of 7440 (95%) of the 7827 women in active labor were ≥ 6 cm dilatation or had received labor stimulation ≥ 6 hours prior to cesarean for arrest of dilatation. Conclusion Women undergoing primary cesarean delivery for arrest of dilatation 15 years before the recommendations of the Obstetrics Care Consensus had received bona fide efforts to achieve adequate labor consistent with the recommendations of the Consensus . Because 95% of these women were ≥ 6 cm dilatation or had received labor stimulation ≥ 6 hours prior to cesarean for arrest of dilatation, these new recommendations are unlikely to change the cesarean delivery rates.

Without cesarean delivery, obstructed labor can result in maternal and fetal injuries or even death given a disproportion in size between the fetus and the maternal birth canal. The precise frequency of obstructed labor is difficult to estimate because of the widespread use of cesarean delivery for indications other than proven cephalopelvic disproportion, but it has been estimated that at least 1 million mothers per year are affected by this disorder worldwide. Why is the fit between the fetus and the maternal pelvis so tight? Why did evolution not lead to a greater safety margin, as in other primates? Here we review current research and suggest new hypotheses on the evolution of human childbirth and pelvic morphology. In 1960, Washburn suggested that this obstetrical dilemma arose because the human pelvis is an evolutionary compromise between two functions, bipedal gait and childbirth. However, recent biomechanical and kinematic studies indicate that pelvic width does not considerably affect the efficiency of bipedal gait and thus is unlikely to have constrained the evolution of a wider birth canal. Instead, bipedalism may have primarily constrained the flexibility of the pubic symphysis during pregnancy, which opens much wider in most mammals with large fetuses than in humans. We argue that the birth canal is mainly constrained by the trade-off between 2 pregnancy-related functions: while a narrow pelvis is disadvantageous for childbirth, it offers better support for the weight exerted by the viscera and the large human fetus during the long gestation period. We discuss the implications of this hypothesis for understanding pelvic floor dysfunction. Furthermore, we propose that selection for a narrow pelvis has also acted in males because of the role of pelvic floor musculature in erectile function. Finally, we review the cliff-edge model of obstetric selection to explain why evolution cannot completely eliminate cephalopelvic disproportion. This model also predicts that the regular application of life-saving cesarean delivery has evolutionarily increased rates of cephalopelvic disproportion already. We address how evolutionary models contribute to understanding and decision making in obstetrics and gynecology as well as in devising health care policies.

Obesity is a known risk factor for cesarean delivery. Limited data are available regarding the reasons for the increased rate of primary cesarean in obese women. It is important to identify the factors leading to an increased risk of cesarean to identify opportunities to reduce the primary cesarean rate.We evaluated indications for primary cesarean across body mass index (kg/m(2)) classes to identify the factors contributing to the increased rate of cesarean among obese women.In the Consortium of Safe Labor study from 2002 through 2008, we calculated indications for primary cesarean including failure to progress or cephalopelvic disproportion, nonreassuring fetal heart tracing, malpresentation, elective, hypertensive disease, multiple gestation, placenta previa or vasa previa, failed induction, HIV or active herpes simplex virus, history of uterine scar, fetal indication, placental abruption, chorioamnionitis, macrosomia, and failed operative delivery. For women with primary cesarean for failure to progress or cephalopelvic disproportion, dilation at the last recorded cervical examination was evaluated. Women were categorized according to body mass index on admission: normal weight (18.5-24.9), overweight (25.0-29.9), and obese classes I (30.0-34.9), II (35.0-39.9), and III (≥40). Cochran-Armitage trend test and χ(2) tests were performed.Of 66,502 nulliparous and 76,961 multiparous women in the study population, 19,431 nulliparous (29.2%) and 7329 multiparous (9.5%) women underwent primary cesarean. Regardless of parity, malpresentation, failure to progress or cephalopelvic disproportion, and nonreassuring fetal heart tracing were the common indications for primary cesarean. Regardless of parity, the rates of primary cesarean for failure to progress or cephalopelvic disproportion increased with increasing body mass index (normal weight, overweight, and classes I, II, and III obesity in nulliparous women: 33.2%, 41.6%, 46.4%, 47.4%, and 48.9% [P.01] and multiparous women: 14.5%, 20.3%, 22.8%, 27.2%, and 25.3% [P .01]), whereas the rates for malpresentation decreased (normal weight, overweight, and classes I, II, and III obesity in nulliparous women: 23.7%, 17.2%, 14.6%, 12.0%, and 9.1% [P.01] and multiparous women: 35.6%, 30.6%, 26.5%, 24.3%, and 22.9% [P.01]). Rates of primary cesarean for nonreassuring fetal heart tracing were not statistically different for nulliparous (P.05) or multiparous (P.05) women. Among nulliparous women who had a primary cesarean for failure to progress or cephalopelvic disproportion, rates of cesarean prior to active labor (6 cm) increased as body mass index increased, accounting for 39.3% of women with class I, 47.1% of women with class II, and 56.8% of women with class III obesity compared to 35.2% for normal-weight women (P.01).Similar to normal-weight women, the indication of cesarean for failure to progress or cephalopelvic disproportion was the major factor contributing to the increase in primary cesarean in obese women, but was even more prevalent with increasing obesity class. The rates of intrapartum primary cesarean prior to achieving active labor increased with increasing obesity class in nulliparous women.

Objective The purpose of this study was to determine if intrapartum contractions of a particular shape (rapid rise with slower return to baseline) are predictive of cephalopelvic disproportion (CPD). Study design In an institutional review board (IRB)-approved study, cohorts of 100 women who underwent spontaneous vaginal delivery (SVD) and 100 who underwent cesarean section (C/S) for CPD or arrest of labor were consecutively identified between January 2004 and March 2005. Inclusion criteria included term, singleton pregnancies, nulliparity, and absence of fetal anomalies. One hour of interpretable electronic fetal monitoring (EFM) was obtained in active labor. Fall to rise (F:R) ratio was calculated by measuring the time for a contraction to return to its baseline from its peak ("fall") and the time for a contraction to rise to its peak ("rise"). The F:Rs were then averaged over the number of contractions. Data were analyzed using Student t test, Chi-square, and Fisher exact tests where appropriate. Results Maternal demographics are listed in Table I. The average F:R ratio was 1.55 for SVD versus 1.77 for C/S, a statistically significant difference ( P = .00003). Analysis of variance revealed this difference persists when controlled for the potentially confounding factors shown. At F:R >1.76, moreover, there was a trend towards larger birth weight ( P = .06) Conclusion Our study demonstrates there is a difference in uterine contraction configuration that is more common in those labors destined for C/S due to CPD. This may indicate the presence of a heretofore unknown feedback mechanism as the uterus adapts to the dysfunctional labor.

Our purpose was to compare the practice patterns and outcomes of physicians delivering in our institution to identify risk factors and management techniques that could explain the differences in individual cesarean section rates.We retrospectively reviewed detailed computerized delivery records (n = 16,230) collected from May 16, 1988, to July 30, 1995. We excluded physicians who had100 deliveries at our institution during the study period. The physicians were divided into two groups depending on whether their individual cesarean section rates were greater than (control group) or less than 15% (target group). Various cesarean section rates, risk factors for abdominal delivery, labor management techniques, and neonatal outcome parameters were calculated for each group. The cesarean section rates of the two groups were analyzed by year to assess changes.As expected by study design, the overall cesarean section rate was markedly different between the two groups (13.8% vs 23.8%). In addition, the primary, repeat, primigravid, and multiparous cesarean section rates were all lower for the target group. The rates of cesarean section for fetal distress (1.5% vs 3.3%) and cephalopelvic disproportion (5.3% vs 8.5%) were also significantly less in the target group. The rates of breech presentation, third-trimester bleeding, and active herpes cesarean sections were not lower. The control group had more postterm (8.6% vs 14.7%) and4000 gm infants (12.0% vs 13.7%) but similar numbers of low birth weight, multiple gestation, and preterm infants. The target group used more epidural anesthesia, oxytocin induction, and trial vaginal births after cesarean delivery and more successful trial vaginal births after cesarean sections. Over the study period the cesarean section rate in the target group remained unchanged, whereas it steadily declined in the control group.Individual physician's lower cesarean sections are primarily obtained by labor management and attempting vaginal birth after cesarean delivery. These practice patterns did not appear to lead to any increase in perinatal morbidity or mortality. Efforts to lower cesarean section rates of individual practitioners should focus on the areas of fetal distress, cephalopelvic disproportion, and repeat cesarean section.

OBJECTIVE: We analyzed the delivery statistics from our institution to describe a successful program of cesarean section delivery reduction and to help us understand what factors explained the reduction. STUDY DESIGN: A retrospective analysis of various cesarean section rates and risk factors from a prospectively collected delivery database of all patients delivered between May 15, 1988, and June 30, 1994. During the study period we instituted a program of increasing awareness, confidential provider feedback, more aggressive laboring techniques, and other clinical guidelines. The delivery data were divided into 6-month intervals and analyzed by χ 2 tables. RESULTS: The overall cesarean section rate fell from 31.1% to 15.4%. Similar reductions were noted in the primary (17.9% to 9.8%) and repeat cesarean section rates (13.2% to 5.7%). The primary cesarean section rate fall was accompanied by a drop in abdominal delivery for cephalopelvic disproportion and fetal distress. The repeat cesarean section rate is explained by a significant increase in trial and successful vaginal birth after cesarean delivery. No increase in maternal, fetal, or neonatal morbidity or mortality was observed. CONCLUSIONS: We have demonstrated that the cesarean delivery rate can be safely lowered in a private hospital without mandated clinical changes. Our data suggest that careful and detailed feedback can lead to improved clinical practice. (AM J OBSTET GYNECOL 1996;174:184-91.)

OBJECTIVE: The purpose of our study was to thoroughly investigate the risk factors of uterine rupture in patients undergoing trial of labor after cesarean section. STUDY DESIGN: We conducted a case-control study of 70 patients with prior cesarean delivery with uterine rupture during trial of labor between January 1983 and June 1990. The risk factors of uterine rupture were identified, and the estimates of the relative risks were reported. RESULTS: The risk of uterine rupture was increased in patients who had an excessive amount of oxytocin, who had exeprienced dysfunctional labor, and who had a history of two or more cesarean deliveries. Epidural anesthesia, macrosomia, history of successful vaginal delivery after cesarean section, unknown uterine scar, and history of cesarean delivery because of cephalopelvic disproportion were not associated with uterine rupture. CONCLUSIONS: We recommend that all patients with a history of cesarean delivery be observed closely for progression of labor. Recognition of an active-phase arrest disorder, despite adequate augmentation with oxytocin, requires operative delivery.

Summary 1. Seven cases of maternal obstetric paralysis occurring in a series of approximately 45,000 deliveries at the Woman's Clinic of the New York Hospital are reported. All seven cases were personally observed by the author. 2. The majority of cases of obstetric paralysis will exhibit a combination of the following characteristics: primipara, prolonged labor, difficult forceps delivery, cephalopelvic disproportion. In addition, x-ray studies show that the pelvis will present certain characteristic features: a short posterior ileum, a sacral ala with shallow anterior concavity, and a promontory which does not encroach on the posterior pelvic capacity. 3. The patient who develops pain, paresthesias, and paralysis of either or both of the lower extremities during labor and/or the puerperium should have an immediate neurological examination. 4. A historical review of maternal obstetric paralysis is presented in an effort to demonstrate the development of the modern teaching. 5. The various theories as to etiology are discussed. The pressure theory, originally advanced by Hunermann, appears to be the most common cause of paralysis. 6. The prognosis as to degree and speed of recovery must be guarded. 7. The prevention of obstetric paralysis depends on recognition of the signs of lumbosacral cord compression, careful evaluation of the patient, and a correct decision as to the method of delivery. 8. Treatment consists of : support of the injured extremity, active and passive motion, galvanic stimulation, vitamin therapy, and the use of a walking brace.

The objective of the study was to investigate the differences in perinatal outcomes between various Asian ethnic subgroups at a national level.This is a retrospective cohort study of all non-Hispanic Chinese, Japanese, Filipino, Asian Indian, Korean, Vietnamese, Samoan, Guamanian, and Hawaiian women whose deliveries were recorded by US birth certificates within the year 2003. Perinatal outcomes were compared between groups and potential confounders controlled for with multivariable logistic regression.We found significant differences (P.001) in the incidence of all perinatal outcomes of interest among the different Asian subgroups. These differences persisted after adjusting for potential confounders. The incidence of diabetes in pregnancy varied from 2.9% (Korean) to 5.7% (Filipina).Our study demonstrates significant differences in preterm labor, primary cesarean delivery, pregnancy-associated hypertension, eclampsia, diabetes in pregnancy, low birthweight, macrosomia, and cephalopelvic disproportion among Asian subgroups at a national level, affirming the importance of examining these subgroups separately.

The place of symphysiotomy in the management of cephalopelvic disproportion is discussed on the basis of the existing literature, reviewing maternal mortality and morbidity after symphysiotomy and the vaginal delivery rate in a subsequent pregnancy after a previous symphysiotomy. These are compared with the outcome of cesarean section performed in similar circumstances.To reduce the maternal mortality associated with obstructed labor, the World Health Organization recommended (1986) more widespread use of cesarean section. However, this procedure is itself associated with significant mortality and morbidity risks in health facilities in rural areas of developing countries where obstructed labor due to cephalopelvic disproportion is most prevalent. In some cases of obstructed labor, symphysiotomy--the artificial separation of the symphysis pubis with a scalpel to enlarge the pelvic diameter--is a viable alternative to cesarean section. The maternal mortality associated with this procedure is negligible. In a series of 1752 symphysiotomies in Africa, there were 3 deaths (0.2% mortality rate), and none of these deaths was related to the procedure itself. This compares with a mortality rate for cesarean section in African hospitals of 1.8%. Complications of symphysiotomy can be virtually eliminated if the procedure is performed only when 1/3 or more of the fetal head has entered the pelvic brim, the fetal head is not felt prominent in from of the symphysis, and the cervix is dilated beyond 7 cm. Since this procedure does not scar the uterus, the concern of future uterine rupture that exists with cesarean section is not a factor. The vaginal delivery rate after previous symphysiotomy is 87% compared to 44% after cesarean section for disproportion. Moreover, the need for blood transfusion--with the attendant risk of human immunodeficiency virus infection--is far less in symphysiotomy. Finally, symphysiotomy is more culturally acceptable in developing countries where cesarean section delivery is viewed with stigma as a failure to achieve "natural" vaginal birth.

Obese adult pregnant women have increased rates of maternal and neonatal complications. Our objective was to examine adverse obstetric outcomes in overweight adolescent women.In a retrospective case-control study of 4822 women who were19 years old, 3324 appropriate-weight subjects (body mass index, 18.5-24.9 kg/m2) and 1498 overweight subjects (body mass index,or = 25 kg/m2) were compared. Frequencies and odds ratios for adverse maternal or neonatal events were computed.Compared with appropriate-weight adolescents, primary cesarean delivery (odds ratio, 1.6; 95% CI, 1.4-1.9), failure to progress/cephalopelvic disproportion (odds ratio 1.6; 95% CI, 1.3-1.9), labor induction (odds ratio, 1.4; 95% CI, 1.3-1.7), pregnancy-induced hypertension (odds ratio, 1.8; 95% CI, 1.4-2.3), preeclampsia (odds ratio, 1.7; 95% CI, 1.2-2.4), and gestational diabetes mellitus (odds ratio, 3.0, 95% CI, 1.6-5.4) were significantly more common in overweight adolescents. Significant neonatal findings included an increased incidence of macrosomia (odds ratio, 1.6; 95% CI, 1.2-2.0) and a decreased incidence of low birth weight infants (odds ratio, 0.6; 95% CI, 0.4-0.8) and small for gestational age infants (odds ratio, 0.8; 95% CI, 0.7-1.0).Overweight adolescent women are at increased risk for adverse neonatal and perinatal outcomes. With rates of overweight increasing overall, overweight in the gravid adolescent is a pressing perinatal and public health concern.

Objective This study was undertaken to identify risk factors for prolonged neonatal intensive care unit (NICU) stay in macrosomic (≥ 4000 g) neonates. Study design A population-based case-control study in which 799 cases of macrosomic neonates with a prolonged NICU stay were compared with macrosomic neonates without a prolonged stay (n = 1598). Results Significant risk factors included: 5-minute Apgar score less than 7: odds ratio (OR) = 43.1; fetal distress: OR = 3.0; birth length less than 20 inches: OR = 2.2; birth weight more than 5000 g: OR = 2.6; maternal diabetes: OR = 3.0; gestational age 37 to 38 weeks: OR = 2.2; cephalopelvic disproportion: OR = 2.5; primary cesarean: OR = 2.6; forceps/vacuum: OR = 1.7. No significant association was seen with labor induction/augmentation or dysfunctional/prolonged labor. Conclusion Prolonged stay in macrosomic neonates was related to fetal distress measures and less to factors related to prolonged labor. Attention to intrapartum fetal status during labor with suspected macrosomia appears to be especially warranted.

Objective The purpose of the study was to evaluate the stability of the maternal pelvis over the course of the third trimester and the puerperium. Study design Pregnant patients were recruited to undergo comparative magnetic resonance–based pelvimetry and fetal ultrasonography at 37 to 38 weeks of gestation. Most of the patients were recruited from a study of women who planned a trial of labor after a previous cesarean delivery for cephalopelvic disproportion. These results have been reported previously. Patients then underwent magnetic resonance–based pelvimetry within 3 days and at 3 months after delivery. Postdelivery analysis was used to answer the question: Do pelvic dimensions change after delivery? Results Eighteen patients completed the study. Eleven of the patients underwent cesarean deliveries, of which 4 deliveries were before labor. Seven patients had successful vaginal births after their previous cesarean delivery. Statistical analysis of the 18 patients determined that pelvic measurements did not demonstrate change over the course the study. Conclusion Serial magnetic resonance–based pelvimetry showed relative stability of pelvic measurements through the course of pregnancy and delivery. If comparative pelvimetry is to be useful as an antepartum predictor of labor success, then it may be possible to obtain reliable pelvimetry in those patients anytime after delivery.

Objective This study was undertaken to develop an easily usable integrated formula for predicting the probability of cephalopelvic disproportion/failure to progress (CPD) and cesarean delivery (CS) as a function of demographic factors in a middle-class private practice, and to evaluate risk factors for CS in a low-risk primiparous population. Methods We studied 3355 primiparous women who delivered singleton births between February 1993 and July 2001 in a large private practice. We calculated body mass index (BMI) and weight gain during pregnancy by using clinical data from a comprehensive clinical database. Multivariable logistic regression analysis was used to estimate the relationship between the probability of CS and CS carried out for CPD and 6 demographic factors: maternal age, maternal height, initial pregnancy BMI, pregnancy weight gain, gestational age, and birth weight. Three methods were used to assess the accuracy of the model: the Hosmer-Lemeshow goodness-of-fit statistic, association of predicted probabilities, and direct comparison of the formula to the actual data. Odds ratios with a 95% CI are also calculated for each of these factors. Results The overall rate of primiparous CS for the practice is 21.7%, with 11.7% carried out for CPD. Formulas were developed to predict the probability of CS and the probability of CS caused by CPD. Our analysis shows that both the risk of CS and the risk of CS caused by CPD are significantly associated with all 6 demographic factors. We also develop an easily usable Web page-based calculator to instantly estimate any woman's probability of a CS or CPD at the beginning or at the end of her pregnancy. Conclusion The probability of CS and CS performed for CPD is higher for shorter, older, more obese women with large pregnancy weight gains, larger fetal birth weights, and longer gestation ages. Accurate formulas that predict the probabilities of CS and CS performed for CPD in this large private practice have been developed.

Objective This study was undertaken to assess feasibility of magnetic resonance imaging (MRI) pelvimetry in conjunction with fetal ultrasonography as a technique in evaluating patients with previous cesarean sections for cephalopelvic disproportion (CPD). Study deisgn Pregnant patients with one previous cesarean section for CPD who planned a trial of labor after cesarean (TOLAC) were recruited to undergo MRI pelvimetry and fetal ultrasonography at 37 to 38 weeks. Entry criteria included no previous successful vaginal deliveries and no contraindications for vaginal delivery in the ongoing pregnancy. A fetal-pelvic index was calculated for each patient but not disclosed to patients or their physicians. The pregnancies were managed routinely. Analysis after delivery was used to ascertain whether this index would have predicted clinical outcome. Results There were no difficulties in performing the MRI or ultrasound. Sixteen patients completed their pregnancies. Three patients did not labor. The fetal-pelvic index was plotted on a scattergram and compared with the outcome. Three discriminatory zones were identified. Five of 6 patients in the most favorable zone delivered successfully. Two patients in the most unfavorable zone had failed vaginal birth after cesarean section (VBAC) attempts. In the 5 patients in the middle intermediate zone, TOLAC success appeared to depend on fetal presentation and gestational age. Conclusion The use of comparative MRI pelvimetry and fetal ultrasonography is feasible in a community hospital. In this pilot study, it appeared to have potential in enhancing the management of VBAC candidates. This technique may allow sorting of patients before labor into zones that would favor or preclude VBAC attempts.

Objective The purpose of this study was to determine whether the level of hospital care affects cesarean delivery rates for women with preeclampsia. Study design We conducted a population-based cohort study using Missouri birth certificate data for 1993 through 1999. Logistic regression was used to analyze data from 13,646 nulliparous women with preeclampsia who were delivered of singleton live births. Results After adjustment was made for gestational age and birth weight, the data showed that women with preeclampsia at primary and secondary hospitals were more likely to be delivered by cesarean delivery (odds ratio, 1.37; 95% CI, 1.24,1.51; and odds ratio, 1.16; 95% CI, 1.07,1.26, respectively) than at tertiary hospitals. For women who were delivered at ≥37 weeks of gestation, cesarean delivery rates were 38.0%, 33.7%, and 30.0% for primary, secondary, and tertiary hospitals, respectively. Dysfunctional labor, cephalopelvic disproportion, and fetal distress were more commonly noted at primary and secondary hospitals ( P Conclusion Levels of expertise and staffing at tertiary hospitals may allow greater attempts and success with vaginal delivery among women with preeclampsia compared with primary or secondary hospitals.

The purpose of this study was to evaluate the effect of increasing birth weight on the success rates for a trial of labor in women with one previous cesarean delivery.To evaluate the effect of increasing birth weight for women who undergo a trial of labor, the medical records of women who had attempted a vaginal birth after cesarean delivery (VBAC) from 1995 through 1999 in 16 community and university hospitals were reviewed retrospectively by trained abstractors. Information was collected about demographics, medical history, obstetric history, neonatal birth weight, complications, treatment, and outcome of the index pregnancy. The analysis was limited to women with singleton gestations with a history of 1 previous cesarean delivery. Because women with previous vaginal deliveries have higher vaginal birth after cesarean delivery success rates, the women were divided into four risk groups on the basis of their birth history. Groups were defined as women with no previous vaginal deliveries (group 1), women with a history of a previous vaginal birth after cesarean delivery (group 2), women with a history of a vaginal delivery before their cesarean delivery (group 3), and a group of women with a vaginal delivery both before and after the previous cesarean delivery (group 4).There were 9960 women with a singleton gestation and a history of one previous cesarean delivery. The overall vaginal birth after cesarean delivery success rate for the cohort was 74%. The overall vaginal birth after cesarean delivery success rates for groups 1, 2, 3, and 4 were 65%, 94%, 83%, and 93%, respectively. An analysis of neonatal birth weights of4000 g, 4000 to 4249 g, 4250 to 4500 g, and4500 g in group 1 showed a reduction in vaginal birth after cesarean delivery success rates from 68%, 52%, 45%, and 38%, respectively. In the remaining groups, there was no success rate below 63% for any of the birth weight strata. For group 1, vaginal birth after cesarean delivery success rates were decreased when the indication for the previous cesarean delivery was cephalopelvic disproportion or failure to progress or when the treatment was either an induction or augmentation of labor. The uterine rupture rate was higher in women for group 1 with birth weights ofor =4000 g (relative risk, 2.3; P.001).Women with macrosomic fetuses and a history of a previous vaginal delivery should be informed of the favorable vaginal birth after cesarean delivery success rates. Given the risks of vaginal birth after cesarean delivery, those women with no history of a vaginal delivery should be counseled that the success rates may be50% when the neonatal birth weight exceeds 4000 g and that the success rates may be even lower if the indication for the previous cesarean delivery was cephalopelvic disproportion or failure to progress or if the treatment requires either induction or augmentation of labor. The uterine rupture rate was 3.6% in women for group 1 with a birth weightor =4000 g.

The purpose of this study was to examine body mass index and pregnancy weight gain as risk factors for primary cesarean delivery in nulliparous women in a middle-class private practice.Primiparous women who delivered in a private practice setting between February 1993 and July 13, 2001, were included. CIs along with Z statistics for paired count data were used to assess the statistical significance and relative importance of the relationships of body mass index and maternal weight gain to cesarean delivery. The effect of body mass index was examined as related to known confounders such as gestational age, birth weight, maternal age, and maternal height.The overall cesarean delivery rate for primiparous women was 21.76%. Risk of cesarean delivery increased consistently and significantly (P.0001) with increasing body mass index. This effect was primarily mediated through an increase in cesarean delivery carried out for cephalopelvic disproportion/failure to progress. In our practice, the primiparous woman whose body mass index is30 kg/m(2) is six times more likely to have a cesarean delivery for the diagnosis of cephalopelvic disproportion/failure to progress than the primiparous woman whose body mass index is20 kg/m(2). This differential in cesarean delivery rate persisted when controlled for birth weight and gestational age and continues to persist when maternal age and height are also controlled. Excessive pregnancy weight gain exerted a statistically significant effect on cesarean delivery rate. This increase was primarily related to cephalopelvic disproportion/failure to progress among the nonobese women.Maternal body mass index is related strongly to the ability of primiparous women to be delivered vaginally without great difficulty. In fact, lean patients are excellent labor performers, particularly in contrast with obese patients. The relationship of increased body mass index to increased cesarean delivery is due to an increased rate of cephalopelvic disproportion/failure to progress. Excessive pregnancy weight gain is associated with a doubling of cephalopelvic disproportion/failure to progress rate in nonobese patients.

Objective The purpose of this study was to determine whether a customized standard of large-for-gestational age (LGA) identifies pregnancies with increased perinatal risk. Study Design We evaluated 7510 estimates of fetal weight to generate a fetal growth curve. Next, we analyzed the gestational age at delivery, physiologic and pathological variables from 5072 pregnancies to predict birthweight, and calculated a customized ideal birthweight and cutoff for LGA. In a separate analysis of 32,271 pregnancies, rates of macrosomia-related adverse outcomes were compared in pregnancies that had been identified as LGA by a customized standard (LGA cust ) and those pregnancies that had been identified as LGA or macrosomic by conventional standards. Results LGA cust pregnancies carried increased risk of shoulder dystocia, third- or fourth-degree laceration, and cephalopelvic disproportion. LGA cust pregnancies that did not meet conventional criteria for LGA/macrosomia were at increased risk of all measured outcomes. Conclusion A customized standard of LGA identifies a previously unrecognized population that is at increased risk of perinatal morbidity.

The purpose of this study was to calculate the number of cesarean deliveries needed to prevent 1 case of obstetric anal sphincter laceration associated with operative vaginal delivery in an at-risk cohort.An institutional, computerized database was used to analyze women with obstructed labor who could have been managed by either operative vaginal or cesarean delivery from September 2006 to March 2008. Women with 1 or more of the following diagnoses comprised the cohort: cephalopelvic disproportion (CPD), arrest of descent, maternal exhaustion, and fetal distress.Fifty (23.9%) out of a total of 209 women managed by operative vaginal delivery experienced an anal sphincter laceration compared to none of 254 women in the cesarean delivery group (P.0001). The ARR therefore was 23.9% (95% confidence interval, 18.1-29.7) and the NNT was 4.2 (95% confidence interval, 3.4-5.5).Five cesarean deliveries are needed to prevent 1 anal sphincter laceration associated with operative vaginal delivery in this cohort.

OBJECTIVE To identify a group of clinical factors that could be used to accurately predict failure in women attempting vaginal birth after cesarean (VBAC). METHODS We conducted a planned secondary analysis of a retrospective cohort study of women who were offered VBAC from 1996 to 2000 in 17 community and university hospitals. We collected information about maternal history and outcomes of the index pregnancy. We used univariable and multivariable statistical methods to develop a multivariable prediction model for the outcome of VBAC failure. RESULTS A total of 13,706 patients attempted VBAC, with a failure rate of 24.5%. Six variables were significantly associated with VBAC failure in our final logistic regression model: gestational age at delivery, maternal age, maternal race, labor type (spontaneous, augmented, or induced), history of vaginal delivery, and cephalopelvic disproportion or failed induction (combined variable) as prior cesarean indication. The area under the receiver operating characteristics curve is 0.717. To achieve a sensitivity of approximately 75%, a false-positive rate of approximately 40% would result. CONCLUSION Our results indicate that significant clinical variables (prelabor and labor) cannot reliably predict VBAC failure. LEVEL OF EVIDENCE II.

Spontaneous labor in patients of different racial groups has been studied relating progress and outcome to whether labor was dysfunctional as defined by the partogram and action line. Forty-three percent of primigravidas and 17.6 to 25.8% of multigravidas passed the action line and had a lower admission cervical dilatation and a longer observed first stage than those patients whose labor progress remained to the left of the action line. White and black primigravidas whose labor progressed to the right of the action line had lower 1 and 5 minute Apgar scores and delivered heavier babies than those to the left. The cesarean section rates were 1.6% and 1.4% (left) and 7.6% and 18.2% (right) in white and black primigravidas, respectively. The cesarean section rate was significantly higher in black primigravidas irrespective of the relationship to the action line due to the high incidence of the complications of hypertension such as fetal distress and abruptio placentae in those in normal labor as well as those in dysfunctional labor due to cephalopelvic disproportion in those patients whose cervimetric progress went to the right of the action line.

A comparison was made of the incidences of cesarean section deliveries between mothers 18 years of age or younger and those 19 to 21 years of age, all of whom were enrolled in a comprehensive program of prenatal care. Also compared were the indications for surgical delivery between the two groups. The rate of cesarean section deliveries was 8.7% among mothers 18 years of age or younger, compared to 14.5% among mothers 19 to 21 years of age. The general-ward cesarean section rate at the same hospital was 19.4%. Since maternal height and weight, and infant's birth weight may affect the diagnosis of cephalopelvic disproportion, these parameters were also evaluated. However, these did not differ significantly between mothers 18 years of age or younger and those 19 to 21 years of age or between vaginal and surgical births in mothers 18 years of age or younger. Thus, cephalopelvic disproportion did not contribute importantly to the cesarean section rate.

In a prospective, randomized study of 96 patients after cesarean section who had endomyometritis, there was a therapeutic cure in 35 of 47 (74.5%) patients who received mezlocillin, in comparison with 42 of 49 (85.7%) patients who received clindamycin and gentamicin (p = 0.17). Only wound infections in the study population were predictive for therapeutic outcome. Four of the five patients who received mezlocillin and none of the three patients who received clindamycin and gentamicin with wound infections were associated with therapeutic failures. This suggests mezlocillin may not be as effective as clindamycin and gentamicin in successfully treating wound infections. The number of vaginal examinations in patients sectioned for cephalopelvic disproportion was associated with increased febrile morbidity, suggesting that an excessive number of vaginal examinations should be avoided in the laboring patient.

This report concerns itself with a brief history of destructive operations on the fetus and with an analysis of the management of 10 patients who presented with some form of obstructed labor and with fetuses who died ante- or intrapartum. Some patients were in an appalling condition at the time their obstetric operations were effected: infected; dehydrated; in two patients prior attempts at delivery under uncertain conditions. Five patients had breech presentations in which the head would not deliver; the remaining had vertex presentations, severe cephalopelvic disproportion, and prolonged rupture of membranes. All 10 patients were managed successfully by some form of destructive operation. In our opinion, destructive operations in areas such as ours represent an infrequent but eminently satisfactory way to solve some difficult obstetric problems.

At the Highland Park Hospital the increase in cesarean section rates has paralleled the national increase. Data from cesarean deliveries performed for cephalopelvic disproportion (a leading reason for cesarean section) in 1969 to 1972 (group 1) and 1979 to 1982 (group 2) were evaluated to determine maternal, fetal, and delivery factors that might be related to the increase in the rates. The data suggested that the more frequent diagnosis of cephalopelvic disproportion and the increased size of the group 2 infants were the primary reasons for the increase in cesarean section rate. This increased rate was paralleled by a decline in forceps-assisted delivery and in perinatal mortality rates.

1. 1. Fifty-nine cases of cervical dystocia are presented by combination and analysis of the data. 2. 2. Three cases followed cervical cauterization, five followed previous surgery on the cervix, and one followed a known previous laceration. It is possible that even untreated chronic cervicitis may cause sufficient fibrosis to impede normal dilation during labor. 3. 3. Forty-three patients were delivered by cesarean section and sixteen vaginally. Six sections were done without labor, three following failure of induction attempts. 4. 4. There were fifty-five cephalic presentations and four breech. Varying degrees of cephalopelvic disproportion were present in eleven cases. There were eighteen occipitoposterior positions and one mentoposterior. The fetal weights were about average, the section babies weighing an average of 10 ounces more than the vaginally delivered babies. 5. 5. The average length of labor of the patients delivered by cesarean section and those delivered per vaginam were about the same. With a little more patience in some of the cases of the former group, vaginal delivery could probably have been successfully accomplished. 6. 6. Twenty-five patients were noted to have uterine inertia. It is suggested that in some of these cases this was the principal factor rather than cervical dystocia in the prolongation of labor, and with further attention to the inertia, there might have been more successful vaginal deliveries. Failure of good labor to develop from an induction attempt does not mean that the patient will never go into labor or that the cervix will not dilate properly.

In this paper information is given concerning 1059 cesarean sections of all types which were performed at the Chicago Lying-In Hospital from July 1, 1915, to July 1, 1929. Since there were 51,323 deliveries at this hospital and its dispensary services, the incidence of abdominal delivery for the last fourteen years was 2.06 per cent, or one cesarean section for every 48.5 cases. The maternal mortality for the 874 cervical operations was 1.26 per cent. If the 21 Porro operations which were performed after a laparotrachelotomy are added, the death rate is 1.23 per cent. For the 147 classic cesarean sections, the mortality was 4.76 per cent and this is reduced to 4.27 per cent if the 17 Porro operations, which were done after a classic cesarean section, are added. All of the figures quoted in this paper are gross figures. None of the statistics was “corrected.” The following information is based only upon the 874 cervical operations. The chief indications for the laparotrachelotomies were cephalopelvic disproportion 42.1 per cent, previous cesarean section with test of labor 11.3 per cent, previous cesarean section without test of labor 6.5 per cent, toxemia without convulsions 9.7 per cent, eclampsia 1.8 per cent, placenta previa 4.8 per cent, abruptio placentae 3.2 per cent, dystocia dystrophia syndrome 4.9 per cent, a number of previous still-births 4.2 per cent, and cardiac disease 3.3 per cent. Only 50 per cent of the patients were in labor at the time of operation, and of these 38.1 per cent had labor pains between 1 and 25 hours, 9.3 per cent had pains between 25 and 50 hours, and 2.6 per cent had been in labor from two to four days. In 21.4 per cent of the cases, the membranes were ruptured when the cesarean section was performed, and the interval between the rupture of the membranes and the time of operation varied from one hour to eight days. Ether was the anesthetic employed in 35.8 per cent of the cases, novocaine alone in 55.1 per cent, novocaine with ether or gas in 6.1 per cent, ethylene in 2.6 per cent and nitrous oxide in 0.4 per cent. During the past year 92 per cent of all the cesarean sections were performed under local anesthesia. Sterilization by means of operations on the fallopian tubes was performed in 9.6 per cent of all the cases. If the Porro operations are included, the incidence of sterilization was 11.7 per cent. The cause of death in the 11 fatal cases was as follows: peritonitis 3, pneumonia (after ether) 2, sepsis 1, gangrenous appendicitis 1, pulmonary embolism 1, antepartum eclampsia 1, postpartum eclampsia 1, and tuberculous meningitis 1. The maternal mortality according to the indications was as follows: cephalopelvic disproportion 0.8 per cent, repeated laparotrachelotomy 1.6 per cent, toxemia without convulsions 1.2 per cent, eclampsia 6.3 per cent, placenta previa no deaths, abruptio placentae 7.1 per cent, cardiac disease 3.4 per cent, and tuberculous meningitis 100 per cent. Fever after operation was present in 43.4 per cent of the cases. The main causes of pyrexia in the 196 cases where the etiology was known, were infected wounds 6.1 per cent, pyelitis and cystitis 4.8 per cent, bronchitis 2.1 per cent, pneumonia 1.3 per cent, grip 1.0 per cent, endometritis 0.9 per cent and lochiometra 0.9 per cent. In 46.7 per cent of the cases the patients left the hospital within fourteen days after operation and in 84.6 per cent they went home within eighteen days. The fetal mortality according to the indications for the operation was as follows: cephalopelvic disproportion 3.3 per cent, repeated laparotrachelotomy no deaths, toxemia without convulsions 7.5 per cent, eclampsia no deaths, placenta previa 23.8 per cent, abruptio placentae 35.7 per cent, and psychosis 100 per cent. The chief causes of death among the 40 infants were as follows: dead before operation 22.5 per cent, prematurity 25 per cent, atelectasis 20 per cent, monsters 10 per cent, and congenital heart disease 5 per cent. Among the 21 patients who had Porro operations there were no maternal deaths and two fetal deaths (9.5 per cent).

An important problem which every obstetrician frequently faces is how to conduct labor safely for both mother and infant. Often this problem is complicated by such factors as strength of uterine contractions, extensibility of the soft tissues, the degree of molding of the fetal head, and cephalopelvic disproportion, which impede and complicate to variable degrees an otherwise normal process. It is in this respect that the use of the x-ray has become a most valuable adjunct in the solution of obstetrical problems. The acceptance of the roentgen pelvimetric technique is based upon reports of numerous corroborating clinical studies by Dyer, 1 Savage, 2 and Roth. 3 A necessary requisite for interpreting and utilizing x-ray pelvimetric results is to establish criteria from which one can draw conclusions as to the expected course of labor and its safest management. In Taiwan (Formosa) external pelvic measurement, which is at present regarded only as a traditional gesture, has been used routinely with the measurement of the diagonal conjugate in cases of suspected pelvic contraction. X-ray pelvimetry was rarely employed until several years ago. Consequently, pelvic measurements and architecture remained obscure. This study is designed to establish various criteria of pelves of Chinese women based upon obstetrical and anthropological factors.

A brief review of the literature relating to roentgenographic cephalometry has been presented. Particular emphasis has been given to the recent work of Cave, and his so-called precision method has been evaluated. If grossly unsatisfactory roentgenograms are excluded—and we are of the opinion that such roentgenograms can usually be excluded—accurate measurements of diameters of the fetal skull in the uterus to within ±6.6 per cent can be obtained by this method in approximately 85 per cent of the cases. In the case of measurements of fetal skulls adjudged to be of grade A in the roentgenogram, accuracy to within ±5.5 per cent was consistently obtained (92 per cent). We believe that a simple, inexpensive, and relatively precise technique of roentgenographic cephalometry might well represent a helpful adjunct in the management of suspected cephalopelvic disproportion in the primigravid woman for whom a trial of labor has been planned and a fetal development above the average is suspected. Although this method, in our limited experience, does not seem to be a method of precision, it is certainly deserving of further investigation.

1. 1. The effect of prolonged pregnancy (past 41 weeks) on fetal and neonatal survival has been analyzed in 63,370 single pregnancies, including 6,624 postterm pregnancies during a recent 2 year period. 2. 2. The perinatal mortality rate at term was 0.7 per cent and postterm was 1.5 per cent. 3. 3. The proportion of infants weighing over 4,000 grams and the incidence of primary cesarean sections done because of cephalopelvic disproportion both doubled postterm. 4. 4. In nulliparas and elderly multiparas there were significant increases in perinatal deaths when pregnancy was prolonged, with the greatest increase occurring in intrapartum fetal deaths in nulliparous patients. 5. 5. Hypertensive disorders and prolonged labor adversely affected the outcome for the postterm fetus. 6. 6. Perinatal death rates directly and indirectly attributable to anoxia more than doubled postterm compared to death rates caused by anoxia at term. 7. 7. The number of postterm infants potentially salvagable by a uniformly safe method of induction of labor at an arbitrary postterm date is relatively small. An inordinately large number of inductions of labor in nulliparas would be required to achieve this result. 8. 8. Induction of labor or cesarean section solely because pregnancy has become prolonged, and in the absence of generally accepted obstetrical indications, would not appear to be justified by the data presented here.

1. 1. One thousand patients were studied to evaluate x-ray pelvimetry. 2. 2. These were all private patients delivered by an associated group, with procedure thereby standardized. 3. 3. The method of obtaining x-ray mensuration was not as important as the interest and experience of the roentgenologist. 4. 4. The Johnson and Snow methods were used to obtain pelvic data and the Ball method to obtain fetal data. One roentgenologist in 880 cases used the Johnson method and two, in 120 cases, used the Snow method. 5. 5. There were 850 primigravidas and 150 multiparas. 6. 6. Thirty-two inlet, 197 midplane, and 17 outlet contractions were found. Twenty-eight were in combination. No outlet contraction was found to exist alone. 7. 7. Inlet contractions were no problem. Outlet contractions were not found alone. Midplane contractions, the most common, were studied in detail. 8. 8. Midplane bi-ischial diameters of less than 9.4 cm., a Mengert Index of less than 84, and the transverse-posterior sagittal index of less than 13.3 cm. in this series were found to be critical. There were exceptions to all indices. 9. 9. A more consistent curve was found in considering cephalopelvic relationship. When the cephalopelvic disproportion was distinguished in normal and contracted pelves, an even finer dividing line was drawn in the prognosis for safe vaginal delivery. 10. 10. A large fetal head can be expected to mold to a greater amount than a small fetal head. Disproportion in normal pelves is due to the large fetal head, in contracted pelves to the small pelvic diameters. This explains why greater disproportions are tolerated in normal pelves. 11. 11. In normal pelves vaginal delivery was the rule until the cephalopelvic disproportion exceeded −200 c.c. In contracted pelves vaginal delivery was limited if the disproportion exceeded −51 c.c. 12. 12. A successful approach has been to consider the fetal skull volume, the pelvic volumetric capacity, and the clinical appraisal of a given patient. 13. 13. In no instance, other than frank pelvic deformity, should the roentgenologist dictate obstetrical procedure. 14. 14. There was a stillbirth rate of 0.7 per cent which included three monstrosities. The neonatal death rate was 0.2 per cent. Prematurity and a cerebral hemorrhage accounted for the two. In no fetal death was a contracted pelvis responsible. Three of these fetal deaths are considered preventable. 15. 15. There was no maternal mortality.

The treatment of 8 cases of posterior face position in labor and of one before the onset of labor is described. The latter was converted to an occiput presentation by the abdominal maneuver of Schatz. During labor four of these positions were converted by the Thorn maneuver to the occiput anterior and safely delivered. Two others were rotated to a mentum anterior and delivered as such with forceps. One patient was delivered by a low flap cesarean section, and one by a supravesical extraperitoneal cesarean section. There were no maternal deaths or stillbirths. The two infants delivered by forceps in the mentum anterior position died during the neonatal period apparently to the effects of birth trauma. Version was not attempted in this series primarily because of (1) a contracted or borderline pelvis; (2) a tight, thin uterus with membranes long ruptured; and (3) an incompletely dilated cervix. The etiology of this abnormal position was not always clear but one constant finding seemed to be relative disproportion between the size of the infant and pelvis. The pelvic asymmetry was demonstrated by the three small android pelves which we were able to check by x-ray, and the fetal factor by one large eleven-pound child and by one small five-pound, twelve-ounce child in a large multiparous woman. Multiparity and relaxed abdominal walls did not seem to be important, as there were four young primiparas with firm musculature and only two had had more than two children. A differential between primary and secondary dolichocephaly could not be established, but it is interesting to note that of the 6 babies whose head measurements were recorded, 5 had an occipitofrontal diameter of 12.5 cm. or greater. The exception was the small child mentioned above whose occipitofrontal measurement was 9.5 cm. Early diagnosis and accurate determination of size and shape of pelvis are essential to the proper conduct of this type of dystocia. X-ray pelvimetry is of assistance but not always conclusive. Where definite cephalopelvic disproportion exists, cesarean section is the method of choice, except that in the cases where labor is far advanced the choice lies between extraperitoneal section, hebosteotomy, and craniotomy. In the borderline case, conversion to the occiput anterior is the safest course. If descent does not then follow, forceps delivery must be added to the three procedures mentioned in advanced cases. In patients with ample pelves, spontaneous rotation to the mentum anterior is the rule. We believe that this explains the constant finding of small pelves in this group of persistent posterior face presentations. This also raises the question of the advisability of rotation to the mentum anterior and forceps delivery in cases with relatively contracted pelves. Extraperitoneal cesarean section and hebosteotomy are definitely less harmful to the infant.

1. 1. From June 2, 1940, to Dec. 31, 1949, there were 500 cesarean sections performed on the obstetrical service at Bellevue Hospital; seventy (14 per cent) of these operations were done after labors of 30 hours or more. 2. 2. The seventy patients with prolonged labors in all but one instance were delivered by low flap cesarean section. 3. 3. Fifty-nine cases (all treated by the lower segment transperitoneal type of operation) in which sulfonamides and/or penicillin were used prophylactically intra and/or post partum are analyzed in some detail. All but three had ruptured membranes for an average duration of about 39½hours. 4. 4. Cephalopelvic disproportion was the most frequent primary indication for operative intervention; the most frequent secondary indication was uterine inertia. 5. 5. The over-all morbidity calculated on the scale described was 54.4 per cent. Local infection of the uterus, herein described as endometritis, was the most frequent cause for morbidity, occurring in 88.9 per cent of all morbid patients. 6. 6. Eight cases in which grossly purulent amniotic fluid was discovered at operation are analyzed in detail. 7. 7. In the latter half of the series, along with a higher incidence of hemorrhages, there was a more marked increase in the administration of blood transfusions; 79.3 per cent of all patients received transfusions at operation or immediately postoperatively. 8. 8. There were three fetal or neonatal deaths, an incidence of 5.5 per cent. In two cases double anesthesias were administered, the first because of a complication of labor, the second for the operation. 9. 9. During the period June 2, 1940, to Dec. 31, 1949, there were no deaths following low flap cesarean section after labors of 30 hours or longer from hemorrhage or infection.

The incidence of cord prolapse at the University Hospital of the West Indies is 0.27 per cent (1 in 370 deliveries). An analysis of 71 cases shows that multiparity, prematurity, antepartum hemorrhage, and multiple pregnancy are the contributory factors more often than cephalopelvic disproportion, hydramnios, and amniotomy. The complication was far more common with male babies and in cases of right anterior occiput or sacrum presentations. The observations are unexplained. The diagnosis in 51 cases was made when the cord appeared at the vulva, and in 15 cases it was made by vaginal or rectal examination. Cord replacement was not attempted. Cesarean section gave better results than vaginal delivery, irrespective of the dilatation of cervix. Among babies weighing over 1,500 grams, the survival rate was 80 per cent (90 per cent when over 2,500 grams). In all the fatal cases the fetal heartbeat disappeared within 30 minutes after the cord became prolapsed.

The relation between body weight and the biparietal diameter of the head in a series of 600 newborn infants has been determined. There is found to be a general correlation between body weight and head size, but the extremes of variation are so great as to make it impossible and dangerous to estimate the possibility of cephalopelvic disproportion by the estimation of body weight.

Plasma levels of cortisol, cortisone, and corticosterone were determined in 13 normal mothers and newborn infants undergoing spontaneous delivery at term. These values were compared with values from 7 normal patients undergoing elective cesarean section and 6 patients undergoing cesarean section for cephalopelvic disproportion following a period of spontaneous labor. Maternal levels of cortisol and corticosterone were consistently higher than fetal levels, and fetal levels of cortisone were significantly higher than maternal cortisone levels. While plasma levels of cortisol, cortisone, and corticosterone were slightly higher in infants born following spontaneous labor, the differences were not statistically significant.

Although the trend in the recent literature is toward an increase in the incidence of cesarean section, mainly due to the addition of new indications, we have found a slight decrease in our section incidence in the last 5 years. Such indications as contracted pelvis, cephalopelvic disproportion, toxemia, and intercurrent disease showed a total decrease of 18 per cent in the past 5 years. We believe that this has resulted from more careful evaluation of our indications and from compulsory consultation by 2 qualified obstetricians before section is done. A thorough discussion of the indications for each section at the weekly staff conferences has further tended to reduce sections done for tenuous indications. Operations performed for the indication previous section were increased by 17 per cent in the past 5 years. It may be that the increasing number of low cervical sections may be a factor in permitting more patients to deliver vaginally rather than performing repeat sections. Such indications as dystocia due to faulty presentation or tumors, hemorrhage, and miscellaneous indications have shown no change in their incidence of section over the past 15 years. It is our belief that the judicious use of intravenous Pitocin has resulted in vaginal deliveries in many patients who previously might have come to section. We have found it extremely useful in patients with uterine inertia and in patients with hemorrhage where conditions for vaginal delivery exist but where delivery must be brought about rapidly. We have also noted a tendency to attempt induction with Pitocin in toxemic patients in whom we previously might have thought that labor could not be induced. Even when the Pitocin induction was not successful on the first attempt it usually resulted in vaginal delivery on a subsequent attempt the following day. We have also used Pitocin in patients in whom the question of slight cephalopelvic disproportion existed and in whom we felt an adequate trial of labor was indicated. With the more forceful uterine contractions produced by Pitocin, we have been able to evaluate such a patient within one to two hours as to the possibility of vaginal delivery. We have noted no untoward effects from this procedure and have frequently saved the patient from an unnecessary section.

1. 1. A survey of 852 cesarean sections performed during the 9 year period from Jan. 1, 1943, through Dec. 31, 1951, is presented. 2. 2. An increase in incidence from 2.5 per cent to 5.1 per cent during the time surveyed is noted, with an average incidence of 3.5 per cent. 3. 3. The most frequently noted indications were previous cesarean section, cephalopelvic disproportion, and hemorrhage. There has been a liberalization of indications for fetal causes, for elderly primigravidas, and for bad obstetrical history. 4. 4. There has been a steady, marked increase in the low cervical two-flap cesarean section with a constant decrease in the classical type. 5. 5. There has been a steady rise in the use of regional rather than inhalation anesthesia, from 42.7 per cent of cases during the first 3 years of the survey, to 76.2 per cent of the cases during the last 3 years. 6. 6. The morbidity rate was 49.2 per cent. The use of antibiotics as a prophylactic measure in all cesarean sections has lowered the rate constantly. It is believed that penicillin should be given prophylactically to all patients in labor or with ruptured membranes for 12 hours. A plea is entered to change the obstetrical standard for the determination of morbidity following cesarean sections. 7. 7. The chief postoperative complications encountered were ileus, wound infection, and thrombophlebitis. 8. 8. The corrected maternal mortality rate was 0.47 per cent. One death was due to anesthesia, 1 death was due to postoperative pneumonia, 1 death was due to hemorrhage, and 1 death was due to paralytic ileus. 9. 9. A gross fetal mortality rate of 6.92 per cent is reported. The corrected fetal mortality rate, eliminating those cases in which the fetal heartbeat was nor heard prior to surgery and cases of fetal abnormalities not compatible with life, was 3.05 per cent.

In a series of 20,883 deliveries, cesarean section was performed on 215 multiparas. Of these multiparas, in twenty-seven patients the primary indication was cephalopelvic disproportion. Because of the concept that multiparas rarely have cephalopelvic disproportion, eleven of these patients had labors of over twenty-four hours, fourteen had a morbid postoperative course, and ten required a cesarean hysterectomy or an extraperitoneal procedure. Multiparas in early labor, with the fetal head not engaged, should receive the same careful investigation for cephalopelvic disproportion that a primipara would receive. The fact that the multipara has had one or more vaginal deliveries should be regarded as an optimistic historical fact, not a diagnostic criterion for spontaneous delivery of the pregnancy at hand.

Laparotrachelotomy in patients with cephalopelvic disproportion can be performed with a maximum maternal mortality of 0.2 per cent as an elective operation and 0.4 per cent after a test of labor (with our criteria). Other indications are usually accompanied by an increased maternal mortality, but the increase should be due to the complication and not to the operation. Total cesarean section mortality can be kept below 1 per cent by the following evaluation of the case: 1. Is there a proper indication—elective, relative, or borderline? 2. Are there any of the following contraindications present? (a) Ruptured membranes over twenty-four hours. (b) Labor over twenty-four hours. (c) Repeated rectal or vaginal examinations. (d) Operative manipulation either for induction of labor or for delivery. (e) Uterine infection. (f) A dead or damaged fetus. 3. Will another procedure, usually a craniotomy, assure a lower maternal mortality?