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To compare obstetric outcome and congenital abnormalities in pregnancies conceived after in vitro maturation (IVM), in vitro fertilization (IVF), and intracytoplasmic sperm injection (ICSI) with those in spontaneously conceived controls.Data were collected from the McGill Obstetrics and Neonatal Database (MOND). All children were examined and classified in a standard manner. Final data were reviewed 12 months after delivery. Pregnancies by IVM, IVF, and ICSI were compared with those of age- and parity-matched controls. Congenital abnormality, gestational age, birth weight, Apgar scores, cord pH, growth restriction, pregnancy complications, mode of delivery, and multiple pregnancy were compared.A total of 432 children were born from 344 pregnancies after assisted reproductive technology (ART) during the study period (IVM 55, IVF 217, ICSI 160). The observed odds ratios (ORs) for any congenital abnormality were 1.42 (95% confidence interval [CI] 0.52-3.91) for IVM, 1.21 (95% CI 0.63-2.62) for IVF, and 1.69 (95% CI 0.88-3.26) for ICSI. Twin pregnancy (IVM 21%, IVF 20%, ICSI 17%) and triplet pregnancy (IVM 5%, IVF 3%, ICSI 3%) were higher than those in controls (1.7% twins and 0% triplets) (P.001). Cesarean delivery rates were higher after ART, even in singleton pregnancies (IVM 39%, IVF 36%, ICSI 36%; controls: 26.3%) (P.05). Apgar scores, cord pH, growth restriction, and pregnancy complications were comparable in all groups.All ART pregnancies are associated with an increased risk of multiple pregnancy, cesarean delivery, and congenital abnormality. Compared with IVF and ICSI, IVM is not associated with any additional risk.

To examine the association between body mass index (BMI) and obstetrical and neonatal outcomes.We conducted a cohort study comparing prepregnant BMI categories with obstetrical and neonatal outcomes using the McGill Obstetrical and Neonatal Database on all deliveries in 10 year period (1987-1997). Prepregnant BMI was categorized into underweight (20), normal (20-24.9), overweight (25-29.9), obese (30-39.9), and morbidly obese (40+). Logistic regression analysis was used to adjust for age, smoking, parity, and preexisting diabetes using normal BMI as the reference.The population consisted of underweight 4,312 (23.1%), normal weight 10,021 (53.8%), overweight 3,069 (16.5%), obese 1,137 (6.1%), and morbidly obese 104 (0.6%). As compared to women with normal BMIs, overweight, obese, and morbidly obese women had an increased risk of preeclampsia 2.28 (1.88-2.77), 4.65 (3.71-5.83), 6.26 (3.48-11.26); gestational hypertension 1.56 (1.35-1.81), 2.01 (1.64-2.45), 2.77 (1.60-4.78); gestational diabetes 1.89 (1.63-2.19), 3.22 (2.68-3.87), 4.71 (2.89-7.67); preterm birth 1.20 (1.04-1.38), 1.60 (1.32-1.94), 2.43 (1.46-4.05); cesarean section 1.48 (1.35-1.62), 1.85 (1.62-2.11), 2.92 (1.97-4.34); and macrosomia 1.66 (1.23-2.24), 2.32 (1.58-3.41), 2.10 (0.64-6.86). Underweight women were less likely to have: preeclampsia 0.67 (0.52-0.86), gestational hypertension 0.71 (0.60-0.83), gestational diabetes 0.82 (0.69-0.97), cesarean section 0.89 (0.81-0.97), shoulder dystocia 0.88 (0.80-0.96), birth injuries 0.40 (0.21-0.77), and macrosomia 0.43 (0.28-0.68) but more likely to have small for gestational age infants 1.54 (1.37-1.72) and intrauterine growth restricted infants 1.33 (1.07-1.67).In a large Canadian teaching hospital, increasing prepregnancy BMI category was associated with an increasing risk of adverse pregnancy outcomes. Underweight prepregnancy BMI was associated with a reduced risk of adverse pregnancy outcomes.

Objectives: To determine the obstetrical outcome of pregnancies initially complicated by a low-lying placenta in the second trimester. Methods: We reviewed the obstetric outcome of all women with singleton deliveries from 1 January 1997 to 31 March 1999 and compared the 703 women with low-lying placentas (placentas in the lower uterine segment) with the 6938 women with placentas that were normally situated in the upper uterine segment at 16–22 weeks’ gestation. Results: Pregnancies complicated by a low-lying placenta in the second trimester were not associated with antepartum hemorrhage, preterm births, preterm prelabor rupture of membranes, pregnancy-induced hypertension, fetal growth restriction or cesarean births. However, they had a higher incidence of postpartum hemorrhage (odds ratio 1.768, 95% confidence interval 1.137, 2.748) than women with a normally situated placenta in the second trimester. Conclusions: Pregnant women with low-lying placentas in the second trimester have a higher incidence of postpartum hemorrhage and hence, it would be prudent to carefully manage the third stage of labor in these women.

To describe temporal trends in fetal "growth" and to examine the roles of sociodemographic, anthropometric, and other determinants.Hospital-based cohort study of 61,437 nonmalformed singleton live births at 22 to 43 weeks' gestational age. Four main measures were examined: (1) birth weight, (2) birth weight-for-gestational-age Z score, (3) small-for-gestational-age (SGA), and (4) large-for-gestational age (LGA), with the latter 3 measures based on a recently developed population-based Canadian reference. Gestational age was based on the last normal menstrual period if confirmed (+/- 1 week) by early ultrasonogram.The mean birth weight and Z score increased significantly (P.0001) among infantsor =37 weeks, with a corresponding reduction in % SGA and a rise in % LGA. No consistent trends were seen among births 34 to 36 oror =33 weeks. When simultaneous changes in maternal prepregnancy body mass index, gestational weight gain, height, cigarette smoking, and other clinical and sociodemographic factors were controlled by using multiple logistic regression, the temporal trends for term infants were no longer evident.Increases in maternal anthropometry, reduced cigarette smoking, and changes in sociodemographic factors have led to an increase in the weight of infants born at or after term.

Objective: To assess fetal, maternal, and pregnancy-related determinants of unexplained antepartum fetal death. Methods: We conducted a hospital-based cohort study of 84,294 births weighing 500 g or more from 1961–1974 and 1978–1996. Unexplained fetal deaths were defined as fetal deaths occurring before labor without evidence of significant fetal, maternal, or placental pathology. Results: One hundred ninety-six unexplained antepartum fetal deaths accounted for 27.2% of 721 total fetal deaths. Two thirds of the unexplained fetal deaths occurred after 35 weeks’ gestation. The following factors were independently associated with unexplained fetal death: maternal prepregnancy weight greater than 68 kg (adjusted odds ratio [OR] 2.9; 95% confidence interval [CI] 1.85, 4.68), birth weight ratio (defined as ratio of birth weight to mean weight for gestational age) between 0.75 and 0.85 (OR 2.77; 95% CI 1.48, 5.18) or over 1.15 (OR 2.36; 95% CI 1.26, 4.44), fewer than four antenatal visits in women whose fetuses died at 37 weeks or later (OR 2.21; 95% CI 1.08, 4.52), primiparity (OR 1.74; 95% CI 1.26, 2.40), parity of three or more (OR 2.01; 95% CI 1.26, 3.20), low socioeconomic status (OR 1.59; 95% CI 1.14, 2.22), cord loops (OR 1.75; 95% CI 1.04, 2.97) and, for the 1978–1996 period only, maternal age 40 years or more (OR 3.69; 95% CI 1.28, 10.58). Trimester of first antenatal visit, low maternal weight, postdate pregnancy, fetal-to-placental weight ratio, fetal sex, previous fetal death, previous abortion, cigarette smoking, and alcohol use were not significantly associated with unexplained fetal death. Conclusion: In this study, we identified several factors associated with an increased risk of unexplained fetal death.

We report on a 4-year-old boy with Knobloch syndrome. He has vitreoretinal degeneration, high myopia, cataract, telecanthus, hypertelorism, and a high-arched palate. He also has a defect of the anterior midline scalp with involvement of the frontal bone as documented by a computed tomography (CT) scan. The brain was normal on CT scan and magnetic resonance imaging. We present a review of the 23 published cases with this syndrome. Our patient illustrates the importance of investigating for underlying ocular and central nervous system pathology whenever midline scalp defects are present.

We report on a child with microcephaly, small facial and body size, and immune deficiency. The phenotype is consistent with Nijmegen breakage syndrome (NBS), with additional clinical manifestations and laboratory findings not reported heretofore. Most investigations, including the results of radiation-resistant DNA synthesis, concurred with the diagnosis of NBS. Cytogenetic analysis documented abnormalities in virtually all cells examined. Along with the high frequency of breaks and rearrangements of chromosomes 7 and 14, we found breakage and monosomies involving numerous other chromosomes. Because of some variation in the clinical presentation and some unusual cytogenetic findings, we suggest that our patient may represent a new variant of Nijmegen breakage syndrome.

BACKGROUND: Earlier studies suggesting an increased recurrence risk of respiratory distress syndrome (RDS) among the subsequent infants of women with a previously affected infant were based on low birth weight inclusion criteria that did not differentiate between preterm and growth-retarded infants. METHODS: We therefore carried out two cohort studies of women who delivered two singleton preterm (gestational age

A 35-year-old woman conceived six months after initiating continuous ambulatory peritoneal dialysis (CAPO). A medical plan was developed to give the patient adequate dialysis for a 1.5 g/kg/day protein Intake. In addition, alterations in calcium, magnesium, and erythropoietin administration were required to reach the objectives set by the obstetrical/renal team. Three weeks prior to delivery, an amniotic leak developed, and vaginal cultures were positive for Escherichia coli. Oral amoxiclllin was administered (500 mg per os q.i.d.) until the day of delivery. A 1545-g baby girl was delivered by cesarean section at 32 weeks. Five days postpartum the patient developed severe peritonitis, which subsequently grew E. coli. The patient fully recovered from the peritonitis, but catheter removal was required. Successful pregnancy can be expected on CAPO, and adequacy can be achieved with aggressive dialysis. Cesarean section delivery should probably be accompanied by full peritonitis therapy.

Previous studies suggest that women with asthma are at increased risk of preterm birth. Moreover, drugs (especially beta-agonists) used to treat asthma are also used to treat preterm labor. The authors carried out a case-control study of 555 women from three hospital centers with idiopathic preterm labor (< 37 weeks), including two overlapping (i.e., non-mutually exclusive) subsamples: cases with early idiopathic preterm labor (< 34 weeks) and cases with idiopathic recurrent preterm labor (< 37 weeks plus a previous history of preterm delivery or second-trimester miscarriage). Controls were matched to cases according to race and smoking history prior to and during pregnancy. All subjects responded in person to questions about atopic, respiratory, obstetric, and sociodemographic histories. Subjects in the early and recurrent preterm labor subsamples were also asked to undergo spirometric testing with methacholine challenge 6-12 weeks after delivery. Cases were significantly more likely to report histories of asthma symptoms and physician-diagnosed asthma (matched odds ratios of 2-3) than controls, particularly those cases with recurrent preterm labor. No significant associations were observed, however, with methacholine responsiveness. These results could not be explained by residual confounding by smoking or other variables, nor by selective recall of asthma symptoms and histories by cases. Women with asthma are at increased risk of idiopathic preterm labor. The fact that no such association was seen with methacholine responsiveness suggests that nonatopic, noncholinergic mechanisms may link bronchial and uterine smooth muscle lability.

To assess the reasons for the Chinese-Caucasian differences in birth weight distributions, a cohort study was carried out involving 18,665 Caucasian and 1,597 immigrant Chinese infants born at Montreal's Royal Victoria Hospital from January 1978 to March 1990 and 1,862 native Chinese infants born at Hefei Maternal and Infant Hospital in Hefei, People's Republic of China, from September 1990 to August 1991. Mean (standard deviation) birth weights in grams were 3,369 (567), 3,195 (493), and 3,171 (428) (p0.01 for differences in mean and variance), and mean (standard deviation) fetal growth ratios (ratio of observed birth weight to average birth weight at the same gestational age) were 0.994 (0.124), 0.963 (0.114), and 0.935 (0.112) (p0.01 for differences in mean and variance), respectively, in the Caucasian, immigrant Chinese, and native Chinese groups. No important or consistent Chinese-Caucasian differences in gestational age were found. When mothers with extreme values for demographic, anthropometric, nutritional, and lifestyle determinants of fetal growth were excluded, the mean fetal growth ratio in Caucasian infants remained significantly higher (p0.01), but the standard deviations became more similar (p0.05): Mean (standard deviation) fetal growth ratios were 1.001 (0.111), 0.966 (0.108), and 0.946 (0.114), respectively. The race-specific rate of growth differed according to period of gestation, with Chinese infants showing more rapid fetal growth early in the third trimester but slower growth near and after term. The authors conclude that the lower mean birth weight in Chinese infants is due to differences in fetal growth (rather than gestational duration) and by their inherently slower growth at or after term. The tight distribution of birth weight among the Chinese is caused partly by their reduced exposure to extremes of maternal determinants of fetal growth (mediated largely by environmental mechanisms) and partly by their inherently different growth pattern, with faster growth at earlier gestations but slower growth at later gestations.

We examined the presence, magnitude, and consequences of systematic and random errors caused by terminal digit preference in the measurement of highest systolic blood pressure during prenatal visits in 28,841 non-referred pregnant women who delivered between 1 January 1982 and 31 March 1990. In the overall distribution of terminal digit readings, 78% were read to 0, 15% to even digits other than 0, 5% to 5, and only 2% to odd digits other than 5. This preference for 0's was consistent across the entire distribution of blood pressure and for a variety of maternal characteristics. The relative frequency of the cutoff value of 140 mmHg (i.e. the percentage of readings on 140 mmHg) within the range containing the value (i.e. 138-142 mmHg) was similar to the relative frequency of other multiples of 0. This was true whether the comparison was made in the overall study sample, or in a pre-selected low-risk subgroup or high-risk subgroup, indicating no systematic bias. On the other hand, a strong tendency to read blood pressure values to the nearest 0 had a marked effect on the classification of hypertension. Changing the definition of hypertension from > or = 140 mmHg to > 140 mmHg produced a reduction in prevalence of hypertension from 25.9 to 13.3% in the overall study sample, from 15.4 to 6.3% in the low-risk subgroup, and from 43.3 to 25.3% in the high-risk subgroup. Epidemiologic studies that compare prevalences of hypertension in different populations based on routine clinical measurement of blood pressure and a single cutoff point should assess the consequences of terminal digit preference in defining hypertension.(ABSTRACT TRUNCATED AT 250 WORDS)

Previous studies suggesting that maternal undernutrition increases the risk of preterm birth have suffered from several methodological shortcomings, including use of total gestational weight gain rather than net rate of gain in maternal tissue, inclusion of induced preterm deliveries, and error-prone gestational age measurements based solely on menstrual dates. The authors have attempted to overcome these shortcomings by investigating the potential etiologic roles of prepregnancy body mass index, net rate of maternal weight gain, height, and a number of other potential biological and sociodemographic determinants of spontaneous (i.e., noninduced) preterm birth in a cohort of 13,102 women with early ultrasound-confirmed gestational age who delivered at the Royal Victoria Hospital in Montreal, Quebec, Canada, between January 1, 1980 and March 31, 1989. Total weight gain, but not body mass index, was highly significantly associated with spontaneous preterm birth, averaging 14.6, 12.5, 9.9, and 9.1 kg, in women delivering at 37 or more, less than 37, less than 34, and less than 32 completed weeks, respectively. Although the relation persisted when weight gain was expressed as an overall rate, it disappeared when the analysis was based on net rate; mean net rates of gain were 0.28, 0.29, 0.27, and 0.27 kg/week, respectively. On the basis of multiple logistic regression analyses, significant determinants of birth at less than 37 weeks included maternal short stature; noncompletion of high school; unmarried status; smoking; diabetes; urinary tract infection within 2 weeks of delivery; prepregnancy hypertension; severe pregnancy-induced hypertension; and previous history of preterm delivery, low birth weight, or neonatal death. Most of these factors retained their significance for birth at less than 34 and less than 32 weeks. In fact, the effect of low maternal education was even stronger at these more severe "levels" of preterm birth. The authors conclude that prepregnancy weight-for-height and gestational weight gain are not important determinants of spontaneous preterm birth and that some previous studies have mistaken an effect of shortened gestation for its cause. Other biologic and social determinants, however, indicate priorities for future research and intervention.

Concern over the postterm pregnancy has shifted from that of the difficult delivery of an excessively large fetus to the current concern with death in utero of an undernourished, small-for-date fetus. Studies of postterm pregnancy before the availability of ultrasonography may have included a large proportion of erroneous menstrual dates. The present study of 7000 infants was undertaken to reassess fetal growth in postterm pregnancies in which the expected date of confinement from last normal menstrual period dating was confirmed (+/- 7 days) by early ultrasonography. Results show a gradual shift toward higher birth weight and greater crown-heel length and head circumference between 273 and 300 days of gestational age. No evidence of postterm weight loss or lower weight for length could be demonstrated. Concern in postterm pregnancy should be for fetal macrosomia, not for intrauterine growth retardation.

Previous prognostic studies of infants with intrauterine growth retardation (IUGR) have not adequately considered the heterogeneity of IUGR in terms of cause, severity, and body proportionality and have been prone to misclassification of IUGR because of errors in estimation of gestational age. Based on a cohort of 8719 infants with early-ultrasound-validated gestational ages and indexes of body proportionality standardized for birth weight, the consequences of severity and cause-specific IUGR and proportionality for fetal and neonatal morbidity and mortality were assessed. With progressive severity of IUGR, there were significant (all P < .001) linear trends for increasing risks of stillbirth, fetal distress (abnormal electronic fetal heart tracings) during parturition, neonatal hypoglycemia (minimum plasma glucose 3 minutes), 1-minute and 5-minute Apgar scores ≤6, 1-minute Apgar score ≤3, and in-hospital death. These trends persisted for the more common outcomes even after restriction to term (37 to 42 weeks) births. There was no convincing evidence that outcome among infants with a given degree of growth retardation varied as a function of cause of that growth retardation. Among infants with IUGR, increased length-for-weight had significant crude associations with hypoglycemia and polycythemia, but these associations disappeared after adjustment for severity of growth retardation and gestational age. Increased length-for-weight and head circumference-for-weight, however, were associated with slightly increased risks of stillbirth and fetal distress, respectively, even after adjustment. It is concluded that IUGR, especially when severe and regardless of cause, is an important determinant of numerous adverse metabolic and asphyxic fetal and neonatal outcomes. Disproportionality is a proxy for severe IUGR and carries little or no additional risk.

Previous studies of fetal growth and body proportionality have been based on error-prone gestational age estimates and on inappropriate comparisons of infants with dissimilar birth weights. Based on a cohort of 8719 infants with validated (by early ultrasonography) gestational ages and indexes of body proportionality standardized for birth weight, potential maternal and fetal determinants of fetal growth and proportionality were assessed. Maternal history of previous low birth weight infants, pregnancy-related hypertension (particularly if severe), diabetes, prepregnancy weight, net gestational weight gain, cigarette smoking, height, parity, and fetal sex were all significantly associated with fetal growth in the expected directions. Consistent with previous reports, maternal age, marital status, and onset or total amount of prenatal care had no significant independent effects. Fetal growth ratio (relative weight for gestational age), pregnancy-related hypertension, fetal sex, and maternal height were the only significant determinants of proportionality. Infants who were growth-retarded, those with taller mothers, those whose mothers had severe pregnancy-related hypertension, and males tended to be longer and thinner and had larger heads for their weight, although these variables explained only a small fraction of the variance in the proportionality measures. Among infants with intrauterine growth retardation, gestational age was not independently associated with proportionality (in particular, late term and postterm infants did not tend to be more disproportional), a finding that does not support the hypothesis that earlier onset of growth retardation leads to more proportional growth retardation. The results raise serious questions about previous studies of proportionality, particularly those suggesting a nutritional etiology for proportional intrauterine growth retardation. They also emphasize the importance of controlling for degree of growth retardation, maternal stature, and pregnancy-related hypertension in evaluating the prognostic consequences of proportionality for mortality, morbidity, and functional performance.

To investigate the intrapartum factors related to umbilical cord nuchal loops (nuchal cord) with particular reference to shoulder dystocia.We studied all singleton pregnancies with a vertex presentation and a birth weight of at least 2500 g from 1 January 1978 to 31 March 1997 and the 13,717 pregnancies with nuchal cord were compared to the 44,136 without nuchal cord.When compared to pregnant women without nuchal cord, a greater proportion of pregnant women with nuchal cord underwent induction of labor (adjusted OR 1.09, 95% CI 1.04-1.15) and augmentation with oxytocin (adjusted OR 1.06, 95% CI 1.01-1.11). They had a longer second stage of labor (p=0.0013) and a greater proportion of primiparous women with tight nuchal cord had second stage of labor that lasted longer than two hours (adjusted OR 1.21, 95% CI 1.03-1.41). The proportion of abnormal fetal heart rate patterns was higher in the presence of nuchal cord (adjusted OR 1.61, 95% CI 1.55-1.68). Shoulder dystocia occurred more commonly in association with nuchal cord, especially when the nuchal cord was tight (adjusted OR 1.50, 95% CI 1.30-1.72 for all nuchal cord; adjusted OR 1.82, 95% CI 1.42-2.34 for tight nuchal cord).Umbilical cord nuchal loops are associated with induction of labor, slow progress of labor, and shoulder dystocia.

Objectives To assess the association between maternal and fetal characteristics and discrepancy between last normal menstrual period and early ( early ultrasound, i.e. menstrual-based gestational age is higher than early ultrasound-based gestational age, so that the expected date of delivery is earlier with the menstrual-based gestational age) discrepancies ≥+7 days, mean birthweight, low birthweight, stillbirth and in-hospital neonatal death. Results Multiparous mothers and those with diabetes, small stature or high pre-pregnancy body mass index were more likely to have positive discrepancies. The proportion of women with discrepancies ≥+7 days was significantly higher among chromosomally malformed and female fetuses. The mean birthweight declined with increasingly positive differences. The risk of low birthweight was significantly higher for positive differences. Associations with fetal growth measures were more plausible with early ultrasound estimates. Conclusions Although most discrepancies between last normal menstrual period- and early ultrasound-based gestational age are attributable to errors in menstrual dating, our results suggest that some positive differences reflect early growth restriction.

Although the fetal death rate has declined over the past 30 years among women of all ages, it is unknown whether particular characteristics of the mother, such as age, still affect the risk of fetal death. We undertook a study to determine whether older age, having a first child (nulliparity), or other characteristics of the mother are risk factors for fetal death.We used data from the McGill Obstetrical Neonatal Database to evaluate risk factors for fetal death among all deliveries at the Royal Victoria Hospital in Montreal (n = 94,346) from 1961 through 1993. Data were available for two time periods (1961 through 1974 and 1978 through 1993); data for 1975 through 1977 have not been entered into the data base and were therefore not included. Using logistic regression, we estimated the effect of specific maternal characteristics and complications of pregnancy on the risk of fetal death.The fetal death rate decreased significantly from 11.5 per 1000 total births (including live births and stillbirths) in the 1960s to 3.2 per 1000 in 1990 through 1993 (P0.001). Between these periods, the average maternal age at delivery increased from 27 to 30 years (P0.001), and the frequency of the diagnosis of diabetes and hypertension during pregnancy increased fivefold (P0.001). Nevertheless, after we controlled for these and other maternal characteristics, women 35 years of age or older continued to have a significantly higher rate of fetal death than their younger counterparts (odds ratio for women 35 to 39 years of age as compared with women30 years of age, 1.9; 95 percent confidence interval, 1.3 to 2.7; for those 40 or older, 2.4; 95 percent confidence interval, 1.3 to 4.5).Changes in maternal health and obstetrical practice have resulted in a 70 percent decline in the rate of fetal death among pregnant women of all ages since the 1960s. Advancing maternal age, however, continues to be a risk factor for fetal death.

We compared rates of preterm and postterm birth according to six algorithms for gestational age (GA) estimates based on last menstrual period (LMP) and early ultrasound (EUS): LMP alone, LMP if the discrepancy between the two estimates was within 14 days and otherwise EUS (14-day rule), a 10-day rule, a seven-day rule, a three-day rule and EUS alone. In a sample of 44,623 births in a Canadian tertiary hospital, the choice of algorithms makes a substantial impact on both preterm and postterm birth rates, even when EUS was used for discrepancies over two weeks.

Early ultrasound scanning estimation of gestational age is known to increase the reported preterm delivery rate (37 completed weeks) compared with estimation by date of the last normal menstrual period, but it is unclear how this systematic difference arises.This study was a hospital-based study of 44,623 women who delivered a live-born or stillborn infant between January 1, 1978, and March 31, 1996, and who had both last normal menstrual period-based and early (usually at 16-18 weeks) ultrasound scan-based gestational age estimates. Cross-classification of the 2 estimates by completed weeks was used to examine the direction and magnitude of the differences between them and to compare the resulting classifications of preterm birth.The early ultrasound scan-based gestational age distribution was shifted uniformly to the left (ie, lower gestational age) relative to the last normal menstrual period gestational age distribution; the early ultrasound scan-based preterm delivery rate was 9.1%, which was 19.5% (n = 659 births) higher than the 7.6% rate by last normal menstrual period (P.0001). The last normal menstrual period estimate exceeded the early ultrasound scan estimate far more often than the reverse, up to and including early ultrasound scan estimates of 40 weeks. No concentration of 4-week discrepancies was observed in either direction, as would be expected with random or systematic errors in recall of the last normal menstrual period. The absolute number of births at 37 to 39 weeks of gestation (by last normal menstrual period) that were reclassified as preterm (n = 1206 births) was much higher than the number of preterm births at 34 to 36 weeks of gestation that were reclassified as term (n = 581 births). The net increase of 625 preterm births (from 581 to 1206 births) that resulted from reclassification of births at 37 to 39 last normal menstrual period weeks accounted for 95% of the total 659-birth increase in early ultrasound scan-based preterm births at all last normal menstrual period gestational ages.Early ultrasound scanning reduces the gestational age estimate across the entire gestational age range; early ultrasound scan-based reclassification of gestational age results in a substantial increase in the prevalence of preterm births. Small downward reclassifications exceed upward reclassifications of similar magnitude, which is consistent with previous reports that delayed (14 days) ovulation is more frequent than early (14 days) ovulation.

Background. Previous etiologic studies have defined intrauterine growth restriction (IUGR) based on a single cutoff. Objective. To assess the relative importance of known etiologic determinants for different degrees (mild versus severe) and timing (preterm versus term) of fetal growth restriction. Design. Hospital-based cohort study. Setting. Tertiary-care university hospital. Participants. Sixty-five thousand two hundred eighty inborn singleton infants without major congenital anomalies delivered between January 1, 1978 and March 31, 1996. Measurements. Comparison of adjusted odds ratios (ORs) and 95% confidence intervals for mild IUGR (defined as birth weight 75% to Results. Maternal prepregnancy overweight (body mass index [BMI] >26.0–29.0 kg/m2) and obesity (BMI >29.0 kg/m2) had stronger protective effects against mild IUGR than against severe IUGR, but most of the determinants showed the opposite pattern. This was especially true for pathologic determinants; ORs (and 95% confidence intervals) for severe versus mild IUGR were 18.5 (14.5–23.8) vs 4.6 (3.6–5.8) for severe pregnancy-induced hypertension (PIH), 3.5 (2.2–5.5) vs 2.3 (1.5–3.4) for prepregnancy hypertension, and 3.4 (2.9–3.9) vs 2.2 (2.0–2.4) for smoking ≥11 cigarettes/day. Primiparity, short stature, prepregnancy BMI, maternal weight gain, and cigarette smoking had significantly larger effects on term IUGR, whereas the effect of severe PIH was more than twice as large for preterm IUGR (OR = 9.7 [7.3–13.0]) as for term IUGR (OR = 4.0 [3.0–5.3]). Conclusion. Pathologic determinants of IUGR such as prepregnancy and PIH and cigarette smoking predispose to more severe fetal growth retardation, and PIH in particular seems to do so before 37 weeks. Growth-restricted newborns are not, therefore, all created equal(ly).

The objective was to determine whether small twins had a survival advantage with respect to small singletons after controlling for other factors associated with adverse perinatal outcome.A hospital-based cohort study included all births between 1980 and 1995 of babies born between 24 and 43 weeks' gestation. Logistic regression was used to estimate the perinatal mortality risks for monochorionic and dichorionic twins with growth restriction after adjusting for gestational age, maternal age, parity, method of delivery, and the presence or absence of congenital malformations.The study sample included 1062 dichorionic twins, 354 monochorionic twins, and 59,873 singletons. Small monochorionic and dichorionic twins showed a similar overall risk of perinatal mortality (odds ratio 1.40, confidence interval 0.86 to 2.25). However, monochorionic twins with birth weights10th percentile faced an increased risk of perinatal death compared with singletons (odds ratio 2.45, confidence interval 1.20 to 5.02). Dichorionic twins had no such increased risk (odds ratio 0.91, confidence interval 0.45 to 1.84).Twins with growth restriction are not protected against perinatal loss, even after adjusting for congenital malformations. In fact, monochorionic twins are more than twice as likely to die in the perinatal period as are their singleton counterparts.

The efficacy of a 3-day course of dexamethasone (0.5 mg/kg/day) in 10 preterm infants (≤30 weeks gestation) with pulmonary interstitial emphysema (PIE) was studied in a retrospective case review. PIE was diagnosed at a median age of 7.5 days and treatment with dexamethasone began at 8.5 days. Seven of the 10 subjects had at least 2 days of conservative treatment (lowered mean airway pressure) preceding dexamethasone during which the mean airway pressure (MAP), oxygenation index (OI) and mechanical ventilation index (MVI) were not significantly different although within 3 days of dexamethasone each variable improved significantly (p < 0.05). Similarly, for all 10 infants, OI and MAP were significantly lower at 3 and 7 days from baseline (p < 0.005). By day 7, FiO2 (p = 0.022) and MVI (p = 0.011) were significantly lower and PIE had resolved on chest X-ray in 7/9 (78%) and improved in the remaining 2/9 (22%). Nine of the 10 infants survived to term. Three days of dexamethasone was associated with significant clinical improvement in most of these infants. The mechanism may relate to reduced airway oedema and inflammation and reduced airway obstruction.

Objective. To describe growth during initial hospitalization for very small premature infants fed intravenous hyperalimentation, then calcium supplemented 1460 mg/L (36.5 mmol/L) 81 kcal preterm formula. Population. A total of 109 survivors whose

Objective To quantify the roles of suspected sociodemographic, anthropometric, behavioral, and pathologic determinants in the etiology of abruptio placentae. Methods We performed a hospital-based cohort study of 36,875 nonreferred births between January 1978 and March 1989. Gestational age was based on menstrual dates confirmed (within 7 days) by early ultrasound. Results Parity, maternal education, pre-pregnancy weight, and the rate of net gestational weight gain did not have significant independent associations with abruption. Significant determinants included the following: severe small for gestational-age (SGA) birth (odds ratio [OR] 3.99; 95% confidence interval [CI] 2.75, 5.77), chorioamnionitis (OR 2.50; 95% CI 1.58, 3.98), prolonged rupture of membranes (OR 2.38; 95% CI 1.55, 3.65), preeclampsia (OR 2.05; 95% CI 1.39, 3.04), pregnancy-induced hypertension without albuminuria (OR 1.57; 95% CI 1.00,2.46), pre-pregnancy hypertension (OR 1.77; 95% CI 1.05, 2.99), maternal age at least 35 years (OR 1.50; 95% CI 1.14, 2.01), unmarried status (OR 1.50; 95% CI 1.13, 1.98), cigarette smoking (OR 1.40; 95% CI 1.00, 1.97 for ten to 19 cigarettes per day and OR 1.13; 95% CI 0.81, 1.59 for at least 20 cigarettes per day), and male fetal gender (OR 1.38; 95% CI 1.12, 1.70). Removal of SGA from the regression model resulted in little change in the magnitude of the other associations. Conclusions Severe fetal growth restriction, prolonged rupture of membranes, chorioamnionitis, hypertension (before pregnancy and pregnancy-induced), cigarette smoking, advanced maternal age, unmarried status, and male fetal gender are significant etiologic determinants of placental abruption. Non-SGA determinants appear to operate largely independently of their effects on fetal growth.

Despite widespread acceptance of the concept of very low birth weight (VLBW), i.e., birth weight of less than or equal to 1,500 g, VLBW infants represent an extremely heterogeneous group of newborns, including those with very immature gestational age and those who are more mature but extremely growth retarded. To demonstrate how use of the VLBW rubric can lead to confounding bias that is not only large in magnitude but impossible to control satisfactorily, the authors divided 640 consecutive live neonates born in the Royal Victoria Hospital, Montreal, Canada, from 1978 to 1987 into two overlapping groups: a VLBW cohort (birth weight, 500-1500 g; n = 573) and a gestational age cohort (gestational age, 23-30 completed weeks; n = 466). Variation in growth status by gestational age was much more uniform in the 23- to 30-week cohort. Thus, although mean birth weight was similar in the 500- to 1,500-g and 23- to 30-week cohorts (1,055 vs. 1,064 g), the 500- to 1,500-g cohort was more mature (mean gestational age, 28.8 vs. 27.8 weeks; upper range, 39.7 vs. 30.9 weeks) and had twice the rate of intrauterine growth retardation (25.7 vs. 11.5%). These differences in maturity and growth resulted in a misleading protective effect of intrauterine growth retardation against in-hospital death in the 500- to 1,500-g cohort (crude odds ratio = 0.55 (95% confidence interval 0.36-0.83] and a greater discrepancy in maturity between cesarean- and vaginally delivered infants (3.1 vs. 1.5 weeks) in the 500- to 1,500-g vs. 23- to 30-week cohorts. These differences arise from inextricable confounding of growth status and maturity in the 500- to 1,500-g cohort, the most mature infants also being the most growth retarded. The removal of well-grown infants with birth weights of greater than 1,500 g from the VLBW cohort leads to a progressively distorted spectrum of growth with advancing gestational age and an artifactual blunting of the beneficial effects of increasing maturity. The authors suggest that whenever fetal growth is an important exposure, outcome, or confounding variable, epidemiologic studies of extremely small or immature newborns should be based on gestational age rather than the VLBW criterion.

Relative Value of Markers of Birth Asphyxia in Infants Developing Hyposic-Ischemic Encephalopathy (HIE)

Context.—Canada and the United States have reported a recent increase in the incidence of preterm birth, but the reasons for this increase are unknown.Objective.—To assess secular trends in preterm birth and its potential determinants.Design.—Hospital-based cohort study.Setting.—Canadian tertiary care university teaching hospital, 1978-1996.Participants.—A total of 65,574 nonreferred live births and stillbirths.Main Outcome Measures.—Changes in occurrence of preterm birth, before and after adjustment for changes in method of gestational age assessment, obstetric intervention, registration of births weighing less than 500 g, and sociodemographic, behavioral, and clinical determinants.Results.—A crude secular increase in preterm births was seen for births less than 37, 34, and 32 completed weeks using 3 alternative gestational age estimation methods. Based on an algorithm incorporating both menstrual and early ultrasound gestational age estimates, rates increased from 6.6% to 9.8% for births at less than 37 weeks' gestation, 1.7% to 2.3% at less than 34 weeks, and 1.0% to 1.2% at less than 32 weeks. Exclusion of births weighing less than 500 g and those with induction or preterm cesarean delivery without labor before each of the corresponding gestational age cutoffs eliminated the secular trends for births before 34 and 32 weeks and attenuated the trend for births before 37 weeks. Nearly half of the remaining trend for births before 37 weeks was accounted for by the increasing use of early ultrasound dating. The residual trend was eliminated after controlling for secular increases in unmarried status and the proportion of women aged 35 years or older. These factors, combined with a decrease in alcohol consumption and increases in histological chorioamnionitis and cocaine use, appear to have counteracted a reduction in preterm birth since the mid-1980s that otherwise would have been observed.Conclusions.—This hospital's increase in preterm births since 1978 parallels increases reported in population-based national studies from the United States and Canada. This trend appears largely attributable to the increasing use of early ultrasound dating, preterm induction and preterm cesarean delivery without labor, and changes in sociodemographic and behavioral factors.

Background: Previous etiologic studies have defined intrauterine growth retardation (IUGR) based on a single cut-off (usually

With parental informed consent 38 of 49 infants of 22-24 weeks have been treated intensively at our institution during 1990-94. Of the 49, 17 (35%) survived. Mean weights were 650g (survivors) and 539g (deaths). Survival rates were higher at 24 than 22 weeks (53% vs 23%), with higher Apgar scores (53% vs 16%), and when a full course of steroids was given (63% vs 21%). Survival was not influenced by route of delivery, nor by infant sex.

Red blood cell volume was estimated indirectly from plasma volume and venous hematocrit measurements in 262 consecutively delivered premature infants of less than 37 weeks’ gestation. Infants with respiratory distress syndrome averaged lower red cell volumes (P0.02) than those without. Fatal cases had the lowest volumes. There was a 10.3% mortality from RDS (respiratory distress syndrome) among the one third of infants with the smallest red cell volumes, and only a 2.3% mortality among the one third with the largest volumes. Red cell volume was shown to be a direct correlate of time of cord clamping and thereby of the amount of placental transfusion, both in infants with and without RDS. From this study it is probable that delayed cord clamping, by allowing placental transfusion, decreases the risk of death from RDS in premature infants. Delay in clamping the umbilical cord for 1–1.5 min is advised in premature births.

As a result of excessive placental transfusion at birth, 8 premature and 3 full-term infants presented with cardiorespiratory and neurological symptoms. Cord clamping was delayed in all infants, and blood volume studies showed polycythemia or hypervolemia. The radiological findings included pulmonary vascular congestion, hyperaeration, pleural effusion, and mild cardiomegaly. Most infants responded to conservative medical management and were asymptomatic within 24 to 72 hours. Three acutely ill infants showed great improvement after phlebotomy, providing further evidence that circulatory overload due to placental transfusion may be the etiological factor in this symptom-complex.

Despite the popular current distinction between "proportional" and "disproportional" intrauterine growth retardation, it has never been shown that variation in body proportions is greater among growth-retarded than nongrowth-retarded infants of the same birth weight, nor that proportionality is distributed bimodally among growth-retarded infants. Based on a cohort of 8719 neonates born between 1980 and 1986 of mothers with concordant (± 7 days) menstrual dating and early ultrasound estimates of gestational age, we used a continuous measure of birth weight for gestational age to define four study groups: nongrowth retarded (n = 5163) and mild (n = 411), moderate (n = 226), and severe (n = 147) intrauterine growth retardation. Compared with non-growth-retarded infants of the same gestational age, growth-retarded infants had substantially lower lengths, head circumferences, and proportionality ratios, and the magnitude of the deficits increased significantly with increasing degrees of growth retardation. When the comparison was based on birth weight rather than gestational age, however, growth-retarded infants had slightly but significantly greater lengths and head circumferences, with increased variability in body proportions, but no evidence of the bimodality that would characterize two distinct subtypes. The analysis suggests that proportionality among intrauterine growth-retarded infants represents a continuum, with progressive disproportionality as severity of growth retardation increases. Moreover, despite evidence of some "sparing," the absolute magnitudes of the deficits in length and head growth remain substantial.

Nutritional support with intravenously administered fat, protein hydrolysate, and glucose was given to 23 premature infants weighing less than 1,500 gm at birth. Growth in the 19 survivors approximated intrauterine growth rates in all dimensions. Complications included sodium imbalance and transient intolerance of the smallest and sickest infants to all components: carbohydrate, protein, fat, and even water. Autopsies in four patients who died did not reveal any untoward findings clearly related to the use of intravenously given lipids. Intravenously given fat has a potentially useful role in the nutritional support of small premature infants.

The purpose of this study is to test the hypothesis that convenience for the physician plays a role in the rate of cesarean section performed because of dystocia. Three time periods were defined (night, 12 midnight to 7:59 AM; day, 8 AM to 5:59 PM; evening, 6 PM to 11:59 PM) based on the work commitments and daily routines of the obstetrician. Rates of cesarean section for dystocia were determined for each of the three time periods. An evening peak in the cesarean section rate is partially but not entirely explained by an evening increase in the proportion of patients in prolonged labor. When patients were stratified according to labor duration (less than 12, 12 to 15, and greater than 16 hours), a persistent evening excess in the rate of cesarean section for dystocia was observed for patients whose labor duration was less than 16 hours. Although this is interpreted as being consistent with the hypothesis of physician convenience, the magnitude of this effect on the overall rate of cesarean section for dystocia is small.

The obstetric management of 340 pregnancies delivered 2 or more weeks postterm and 1408 pregnancies delivered at 41 weeks is compared with that of 5915 pregnancies delivered at 39 to 40 weeks. In all patients menstrual dating was confirmed by early ultrasonographic examination. Postterm labor in primiparas resulted in a high cesarean section rate because of failure to progress; this increased rate was observed even after controlling for induction of labor and the size of the infant. We suggest that primiparas who go postterm often have increased uterine dysfunction. Uterine dysfunction accounts for the increase in the cesarean section rate and is a partial explanation for "failed" inductions.

The effect of cesarean section on the condition at birth in cases of preterm breech presentation was studied in consecutively delivered infants in two time periods. Delivery was rarely (8%) by cesarean section in 1961 to 1974 and usually (89%) by cesarean section in 1978 to 1984. The increased cesarean rate did not reduce the incidence of severe depression, which was double that in control cases with cephalic presentations in both periods. Breech births did not have a higher mortality rate than cephalic births in either period; birth trauma and encephalopathy were similar in both periods. Cesarean section was therefore not found to reduce either the incidence of depression at birth or the mortality. However, head entrapment was responsible for the deaths of seven of 55 live-born infants delivered vaginally at 25 to 28 weeks' gestation, all weighing less than 1000 gm. Although cesarean section is at present performed least often among these extremely premature infants, it is in these cases that it may prove most beneficial.

To assess postdate fetal risk, pregnancies in which menstrual history was confirmed by early ultrasound examination were reviewed; 5915 pregnancies within 1 week of term, 1408 1 to 2 weeks postdate, and 340 at least 2 weeks postdate. Fetal distress and meconium release were twice as frequent and meconium aspiration eight times as frequent postterm. Birth asphyxia was unrelated to gestational age. Fractures and palsies were more frequent because of primiparity and macrosomia. Only one antepartum fetal death occurred in 1748 postdate pregnancies. Review of 674 perinatal deaths at 37 plus weeks in Quebec showed no increase in deaths postterm. The increase in fetal distress and meconium aspiration postterm without an increase in birth asphyxia or fetal death may reflect greater responsiveness of the more mature fetus to mild asphyxic insults. Findings of this study could not justify increased fetal monitoring in postdate pregnancies.

The well-known increased risk of the respiratory distress syndrome in a twin born second as compared with the twin born first is usually attributed to the second twin's predisposition to depression at birth ("asphyxia"). We analyzed the etiologic roles of birth order, presentation, and depression at birth in the development of the respiratory distress syndrome in matched case-control populations drawn from 221 preterm twin pairs. Among the 39 twin pairs discordant for respiratory distress syndrome, the second twin was the affected member in 31 pairs. Second birth order was the only independent risk factor, but only in vaginal deliveries (matched odds ratio, 14.2; 95 percent confidence interval, 2.5 to 81.1). Second twins delivered abdominally did not have an increased risk relative to first twins (odds ratio, 0.9; confidence interval, 0 to 17.8). When depression at birth was evaluated as an outcome variable, malpresentation, rather than birth order, was the major risk factor (independent matched odds ratios of 2.7 [confidence interval, 1.0 to 7.5] and 1.3 [0.7 to 2.5], respectively). Thus, second twins' increased risk of respiratory distress syndrome cannot be explained by a predisposition to depression at birth; a more important factor may be that second twins do not benefit from the salutary effects of labor to the same extent as first twins.