Search

Given the increasing rates of labor induction and cesarean delivery, and efforts to reduce early term births, we examined recent trends in methods and timing of delivery.We identified delivery methods and medical indications for delivery from administrative hospital discharge data for 231 691 deliveries in 2006 and 213 710 deliveries in 2010 from 47 specialty care member hospitals of the National Perinatal Information Center/Quality Analytic Services. In a subset of 17 hospitals, we examined trends by gestational age.From 2006 to 2010, there was an 11% increase in labor induction and a 6% increase in cesarean delivery, largely due to repeat cesareans. There was a 4 per 100 reduction in early term births (37 to 38 weeks), mostly due to a decline in non-medically indicated interventional deliveries.We report a shift in deliveries at 38 weeks, which we believe may be attributed to efforts to actively limit non-medically indicated early term deliveries.

Objectives: Oral squamous cell carcinoma generally occurs in older men and is associated mostly with tobacco and alcohol as the primary risk factors. The incidence of oral squamous cell carcinoma in younger patients has increased. We report a case of a young woman, 25 weeks pregnant, who presented with stage IV carcinoma of the oral tongue. Methods: The following is a case presentation and literature review. Results: The patient presented with T4 N3 M0 oral tongue cancer. A team consisting of a head and neck surgeon, a radiation oncologist, a medical oncologist, and a maternal-fetal medicine specialist was assembled. The patient initially refused surgery. Chemotherapy was initiated until 32 weeks' gestation. After an infant boy was delivered via cesarean section, the patient began concurrent irradiation and chemotherapy, which induced complete regression of the primary tongue neoplasm with a partial response of the neck nodes. The patient underwent bilateral neck dissection followed by hemiglossectomy for recurrence. Conclusions: Management of advanced oral carcinoma in pregnancy presents a unique set of challenges. Few studies have described chemotherapy and radiotherapy during pregnancy, and long-term results are needed. Care must be taken to balance appropriate and adequate treatment of disease and to ensure the safety of the patient and the fetus.

Objective To evaluate the usefulness of fetal fibronectin and home uterine contraction assessment in predicting preterm birth (before 34 weeks) in at-risk asymptomatic women. Methods One hundred fifty women were enrolled prospectively; five were lost to follow-up, leaving 145 women available for analysis. Because patients with preterm labor before 34 weeks' gestation most commonly develop this problem after 28 weeks, the period of 26–28 weeks' gestation was selected prospectively as the first window for prediction and study analysis. Eighty-five of 145 asymptomatic women at high risk for preterm birth had both home uterine contraction assessment of 2 hours per day and one or more cervical sampling(s) for fetal fibronectin measurement at 26–28 weeks. A positive home uterine contraction assessment was defined as contractions exceeding two per hour averaged over the 2-week study interval. Positive fetal fibronectin was defined as greater than 50 ng/mL. Results Fourteen of the 85 women (16.5%) delivered before 34 weeks. Home uterine contraction assessment alone had a sensitivity, specificity, positive predictive value, and negative predictive value for preterm birth of 64, 85, 45, and 92%, respectively; fetal fibronectin alone was associated with values of 43, 89, 43, and 89%, respectively. A positive home uterine contraction assessment was associated with a relative risk (RR) for preterm birth of 5.9 (95% confidence interval [CI] 2.4–14.2), whereas a positive fetal fibronectin demonstrated an RR of 3.8 (95% CI 1.5–9.4). When both assessments were positive, all patients delivered before 34 weeks and there was an RR of 27.0 (95% CI 8.7–84.1) compared with those with both tests being negative. Only two patients with both tests negative delivered before 34 weeks (negative predictive value 96%). Conclusion Both the home uterine contraction assessment and fetal fibronectin accurately predicted preterm birth before 34 weeks. When both tests were combined, the predictive ability improved substantially.

Aims: The objective of this study was to examine the impact of one trial (the HYPITAT trial) on management of gestational hypertension. Study design: This is a retrospective cohort study of 5077 patients delivered at our institution from 7/1/2008 to 6/15/2011. “Pre-HYPITAT” was defined as 7/1/2008–9/30/2009 and “Post-HYPITAT” as 10/1/2009–6/15/2011. The primary outcome is the rate of delivery intervention for gestational hypertension. Secondary maternal and neonatal outcomes were analyzed in patients with gestational hypertension only. Statistical analyses included the χ2-test, Fisher’s exact test, and the two-sample t-test. Results: The rate of delivery intervention Pre-HYPITAT was 1.9%, compared to 4% Post-HYPITAT (P Conclusion: There was a statistically significant increase in delivery intervention for gestational hypertension at our institution after the publication of the HYPITAT trial. There was no significant change in immediate maternal or neonatal outcomes for patients with gestational hypertension.

Objective: The objective of this study was to reevaluate the incidence of occult early midtrimester intraamniotic infection in asymptomatic patients at the time of genetic amniocentesis.Methods: A total of 177 amniotic fluid (AF) specimens from patients referred for genetic amniocentesis between 15 and 20 postmenstrual weeks were evaluated for the presence of bacteria by detailed light microscopy, after Gram and Wright stain, and by cultures for aerobic and anaerobic baceria, Mycoplasma sp., and Ureaplasma urealyticum. Seventy-seven AF specimens were also tested for the presence of bioactive leukoattractants by a leukotaxis bioassay.Results: All fluids were negative for bacteria and bioactive leukoattractants [95% confidence interval (CI), 0–1.9%; 99% CI, 0–2.9%]. This is significantly less than a recently reported incidence of 5.09% (P = 0.002). Incidentally, artifacts with light microscopic morphology consistent with spermatozoa were found during the detailed light microscopic evaluation of AF Gram stains from 2 (1.1%) AF samples in otherwise uneventful pregnancies, a previously unreported finding. Scanning electron microscopy was used to confirm the light microscopic findings.Conclusions: Occult intraamniotic infection in the second trimester is not as high as recently reported. AF culture in all cases of second-trimester amniocentesis is not necessary. The identification of spermatozoa on Gram stain of second-trimester AF specimens needs further confirmation.

Hypertrophic cardiomyopathy and abnormal ventricular diastolic filling in the infant of the diabetic mother is related to poor maternal glycemic control. Evaluation of fetuses of well controlled diabetic mothers has not been examined. Eleven fetuses of nondiabetic mothers (normals) and 9 fetuses of well controlled insulin-dependent diabetic mothers (FODMs) underwent serial evaluation of cardiac growth and ventricular diastolic filling using M-mode and Doppler echocardiography at 20-26 weeks' (period 1), 27-33 weeks' (period 2), 34-40 weeks' (period 3),m and 48-72 hours after birth (period 4). Indices of right and left ventricular diastolic filling included time velocity integral ratios (E/A and %E/E+A). Cardiac growth and birth weight in the two groups were similar consistent with "good" glycemic control. This conclusion was supported by similar maternal glycosylated hemoglobin (%A1C) prenatally and newborn %A1C and C-peptide values postnatally. Heart rate before and after birth and placental resistance prenatally were similar. Both normals and FODMs demonstrated an increase in left ventricular E/A and %E/E+A ratios from period 1 to 4 (p < 0.0001). This shift occurred earlier (by period 2) in normals (p < 0.01). Right ventricular filling ratios increased by period 4 in normals only (p < 0.01). No differences were noted between the groups during any period. Good glycemic control in FODMs results in normal cardiac growth and ventricular diastolic filling. Progression of diastolic filling is abnormally delayed, however, and is presumably more exaggerated in poorly controlled diabetics.

The goals of this study were (1) to determine immunoreactive neutrophil attractant/activating peptide-1/interleukin-8 levels in amniotic fluid from patients with preterm labor and (2) to compare neutrophil attractant/activating peptide-1/interleukin-8 levels, amniotic fluid culture, Gram stain, and the leukotaxis bioassay for their ability to predict histologic chorioamnionitis and clinical outcome.Amniotic fluid was collected by amniocentesis from 55 patients with idiopathic preterm labor and three patients with preterm labor and clinical chorioamnionitis. Gram stain, culture (aerobic, anaerobic, and Mycoplasma species), leukotaxis bioassay, and a commercially available neutrophil attractant/activating peptide-1/interleukin-8 enzyme-linked immunosorbent assay (sensitivity 1 ng/ml) were performed on the amniotic fluid samples. Placentas and chorionic membranes were evaluated for evidence of histologic chorioamnionitis in patients delivered preterm.All patients with detectable leukoattractants by the leukotaxis bioassay had neutrophil attractant/activating peptide-1/interleukin-8 levels above the threshold of the assay. The presence of amniotic fluid neutrophil attractant/activating peptide-1/interleukin-8 is a more sensitive marker for histologic chorioamnionitis and delivery before 34 weeks than is amniotic fluid culture (100% vs 59%, p0.01; and 95% vs 56%, p0.01, respectively). Also, of patients in idiopathic preterm labor those without amniotic fluid leukoattractants (group 1) had the lowest amniotic fluid levels, followed by patients with amniotic fluid leukoattractants and a negative culture (group 2) and patients with amniotic fluid leukoattractants and a positive culture (group 3) who had the highest levels (group 1 vs group 2, p0.001; group 2 vs group 3, p0.01).Amniotic fluid neutrophil attractant/activating peptide-1/interleukin-8, like the leukotaxis assay, is an accurate antepartum predictor of histologic chorioamnionitis and subsequent early delivery in patients with preterm onset of labor. This study supports the role of neutrophil attractant/activating peptide-1/interleukin-8 in the recruitment of neutrophils into chorionic membranes and placenta during developing intrauterine infection.

Direct thrombin inhibitors are commonly used anticoagulants in patients with known or suspected heparin-induced thrombocytopenia (HIT). All three direct thrombin inhibitors available in the United States-argatroban, bivalirudin, and lepirudin-are pregnancy category B drugs based on animal studies, but little data are available on the safety of these agents during human pregnancy. Whereas several case reports support the safe use of lepirudin, only one case report has been published with argatroban and none with bivalirudin. We describe a 26-year-old pregnant woman with portal vein thrombosis and thrombocytopenia treated with argatroban for possible HIT during her last trimester. An argatroban infusion was started at 2 microg/kg/minute during her 33rd week of pregnancy, with the dosage titrated based on the activated partial thromboplastin time; infusion rates ranged from 2-8 microg/kg/minute. Treatment continued until her 39th week of pregnancy, when labor was induced. Argatroban therapy was discontinued 7 hours before epidural anesthesia. The patient successfully delivered a healthy male newborn, devoid of any known adverse effects from argatroban. The infant was found to have a small ventricular septal defect and patent foramen ovale at birth, but it is unlikely that these were caused by argatroban since organogenesis occurs in the first trimester. Even though the cause of this patient's thrombocytopenia was later determined to be idiopathic thrombocytopenic purpura, this is an important case that adds to the literature on use of argatroban during pregnancy.

The metabolism of arachidonic acid (AA) and the transfer of its metabolites was determined in in vivo perfused placental tissue from normal pregnancies and those complicated by maternal insulin-dependent diabetes mellitus (IDDM). 14 C-labbeled AA was recirculated in the fetal circulation for 60 min while 3 H-AA was recirculated in the maternal circulation. Placental effluent was subjected to high perfomence liquid chromatography (HPLC) and analysis of dual-label scintillation counts. Placentae from IDDM pregnancies converted 3–6 times more radiolabelled AA to eicosanoids than did normal placentae. In addition, the transfer pf eicosanoids into the opposing circlulation was doubled in placentae from IDDM pregnancies compared to normal placentae. The predominant direction of eicosanoid transfer in both groups of placentae was in the fetal-to-maternal direction. The relative amoounts of eicosanoids produced was also latered in placentae from IDDM preganancies. Increased amounts of thromboxane (Tx) B 2 and hydroxyeicosatetraenoic acids (HETEs) were present in both circulations of placentae from IDDM preganancies. Level of 6-keto prostaglandin F 1a (6KPGF 1a ) were significantly reduced in both circulation in placetae from IDDM preganancies. Thus, the ratio of TxA 2 to PGI 2 and the ratio of HETEs to PGI 2 were both significantly increased in placentae from IDDM preganancies. These results suggest an imbalance in eicosanoid production which may be relevant to abnormal placental structure and function in IDDM pregnancies.

A low-sulfated chondroitin sulfate proteoglycan (CSPG) has been shown to be the receptor for the adherence of Plasmodium falciparum-infected red blood cells (IRBCs) in human placenta. Recently, hyaluronic acid (HA) has been suggested as an additional receptor even though IRBC binding to HA and the presence of HA at locations where IRBCs adhere in the placenta have not been established. In this study, we investigated whether HA is also a receptor for IRBC binding. IRBCs from infected placentas as well as those from different laboratory strains could bind to CSPG but not to HA. In a cell depletion assay, IRBCs from infected placentas could bind quantitatively to CSPG. Although CSPG is present both in the intervillous space and on the syncytiotrophoblast surface, HA is absent in these locations. These data conclusively demonstrate that CSPG, but not HA, is a receptor for IRBC adherence in the placenta. Our data also show, for the first time, that the IRBC-binding CSPG in the placenta is of fetal origin and that, in P. falciparum-infected placentas, the CSPG level is significantly increased, which could exacerbate IRBC adherence and placental pathogenesis. These results have important implications for the development of anti-IRBC adhesion-based vaccine for pregnancy-associated malaria.

This study used population-based data to examine how health status and risks vary by reproductive life stage, with particular focus on the proximal risks for preterm birth and low birthweight (LBW) infants in preconceptional and interconceptional women. Data are from the Central Pennsylvania Women's Health Study (CePAWHS), which included a telephone survey of a representative sample of 2,002 women ages 18-45 years residing in largely rural central Pennsylvania. Women were classified according to reproductive stage--preconceptional, interconceptional, and postconceptional--on the basis of pregnancy history and reproductive capacity. Multiple indicators of health status and health risks were examined by reproductive stage, stratified by age group (ages 18-34 and ages 35-45). Results show that many risk factors varied significantly by reproductive stage and by age group within reproductive stage. Preconceptional and interconceptional women exhibited several unhealthy behaviors (e.g., binge drinking, nutritional deficits, physical inactivity). Younger pre- and interconceptional women (ages 18-34) had more gynecologic infections, some less favorable health behaviors, and more psychosocial stress than older women (ages 35-45) in the same reproductive stages. Older preconceptional women were more likely to have chronic conditions (hypertension, high cholesterol) than younger preconceptional women. Results suggest how interventions could be tailored to women's reproductive stages.

This retrospective study was designed to evaluate individual sonographic parameters that might help differentiate congenital diaphragmatic hernia (CDH) from other noncardiac thoracic masses such as cystic adenomatoid malformation of the lung (CAMI ) and congenital lobar emphysema (CLE) prenatally. Twenty-four cases of CDH, CAML, and CLE detected during prenatal ultrasound and documented postnatally (with surgical, autopsy, or radiological proof) were identified through extensive chart and record review. The hard copy gray-scale images were retrospectively reviewed for imaging characteristics that may differentiate the three entities. Additionally, the prospective diagnosis during prenatal ultrasound was also compared with the postnatal diagnosis. The most reliable indicators in our retrospective review included confident visualization of a diaphragmatic defect (92.3/100.0 PPV/NPV, p ' 0.002) and/or localization of the stomach within the chest as well as the presence of severe cardiac deviation (both 92.3162.5 PPV/NPV, p ' 0.01). Other sonographic indicators (including the presence of cystic areas, side and size of the lesion and the presence of polyhydramnios) offered lower levels of sensitivity and specificity. Prospective diagnosis during real-time assessment was also integral, offering > 80% sensitivity and specificity (p c 0.001). Accurate prenatal diagnosis of CDH is difficult despite the relative frequency of this lesion. The classic triad of a thoracic mass accompanying a displaced heart, absence of a normally positioned fluid-filled stomach and polyhydramnios, although seen with CDH, may not adequately differentiate this entity from other noncardiac fetal thoracic masses. Real-time assessment remains integral to the appropriate diagnosis.

Gastric dysrhythmias have been recorded from patients with a variety of nausea syndromes. The aim of this study was to measure gastric myoelectric activity in women with and without nausea during the first trimester of pregnancy. In 32 pregnant women gastric myoeletric activity was recorded for 30-45 min with cutaneous electrodes that yielded electrogastrograms (EGGs). Frequencies of the EGG waves were analyzed visually and by computer. Subjects rated their nausea at the time of EGG recording on a visual analog scale with 0 representing no nausea and 300 mm severe nausea. Gastric dysrhythmias were found in 26 pregnant subject: Seventeen had tachygastrias (EGG frequencies of 4-9 cpm), five had 1- to 2-cpm EGG waves, and four had flat-line patterns Mean nausea scores of the subjects with tachygastrias, 1- to 2-cpm, and flat-line patterns were 64.8 +/- 13, 93.4 +/- 23, and 77.2 +/- 36, respectively. Six pregnant subjects had normal 3-cpm EGG patterns, and their nausea scores averaged 2.8 +/- 1.1 (P less than 0.05 compared with nausea scores in subjects with tachygastrias, 1- to 2-cpm, and flat-line rhythms). Six subjects with gastric dysrhythmias during pregnancy were restudied after delivery; each of these subjects had normal 3-cpm EGG patterns and none had nausea. Thus, gastric dysrhythmias are objective pathophysiologic events associated with symptoms of nausea reported during the first trimester of pregnancy.

Placental tissue from nondiabetic term pregnancies and pregnancies complicated by maternal insulindependent diabetes mellitus (IDDM) was perfused in vitro to compare the transfer and lipid distribution of arachidonic acid (AA). Radiolabeled albumin-bound AA was administered into the maternal afferent circulation, and samples of fetal and maternal effluent were collected at 10-min intervals. Perfused placental tissue was collected at the end of each experiment. The effluent was analyzed for total radioactivity, and extracts were subjected to thin-layer chromatography for the assessment of radioactivity associated with various lipid fractions. Placental AA uptake was significantly increased in perfused tissue from diabetic pregnancies (0.88 vs. 1.72 nM · min−1 · g−1 in nondiabetic and IDDM, respectively; P < 0.01), as was AA transfer (0.22 vs. 0.42 ml/min in nondiabetic and IDDM, respectively; P < 0.01). However, transfer of the highly diffusible marker substance antipyrine was significantly reduced in IDDM placentas (1.79 vs. 2.49 ml/min in IDDM and nondiabetic, respectively; P < 0.01). Compared with nondiabetic placentas, incorporation of AA into triglyceride was significantly increased in both maternal and fetal effluents and in placental tissue from IDDM pregnancies, whereas the percentage of AA remaining unesterified was reduced in both placental tissue and fetal effluent. Incorporation of AA into phosphoglycerides was significantly reduced in placental tissue but increased in fetal effluent in placentas from IDDM pregnancies. The results of these studies suggest that transfer and lipid distribution of AA are significantly altered in placentas from IDDM pregnancies. These findings may be relevant to the increased incidence of abnormal fetal growth and development associated with IDDM pregnancies.

We tested these hypotheses: (1) that amniotic fluid from patients with idiopathic preterm labor and histologic chorioamnionitis contains leukoattractants and (2) that the detection of amniotic fluid leukoattractants is an accurate predictor of tocolytic efficacy.Amniotic fluid from 86 patients in idiopathic preterm labor was evaluated by microbiologic tests and leukotaxis assay. The tests' ability to predict histologic chorioamnionitis and response to tocolysis (51 tocolytic candidates) is established. Statistical analysis was performed with Fisher's exact test and unpaired Student t test.The detection of amniotic fluid leukoattractants was a better predictor of histologic chorioamnionitis (97%) than were amniotic fluid microbiologic tests (62%) (p less than 0.01). Also, in patients with detectable amniotic fluid leukoattractants tocolysis failed significantly more often than in patients without detectable leukoattractants (93% vs 7%, p less than 0.01).The presence of leukoattractants in amniotic fluid detected by the leukotaxis assay accurately identifies histologic chorioamnionitis and can additionally predict tocolytic efficacy in patients with idiopathic preterm labor.

Hypertrophic cardiomyopathy & abnormal ventricular compliance (VC) in the infant of the diabetic mother is related to poor maternal glycemic control. We prospectively evaluated cardiac growth, VC, & somatic growth in 11 normal (N) & 8 nongestational insulin dependent diabetic (D) pregnancies using tetal echo from mid gestation to term. Studies were performed at gestational age (GA) P1) 20-26 wks; P2) 27-33 wks; P3) 34-40 wks & P4) 48-72 hrs postnatally. Septal (S) wall thickness (mm) in diastole was obtained using M-mode echo (4 chamber view). Indices of right & left VC were obtained from diastolic tricuspid & mitral E & A wave time velocity integral ratios (TViE/A, MViE/A). Weight (W) in grams was estimated from biparietal diameter & abdominal circumference. Glycemic control was measured from % glycosylated hemoglobin (A1C). Placental resistance was evaluated by the Pulsatility Index (PI) from umbilical artery flow. Values are expressed as the mean ± 1 SD.

Nineteen cases of nonimmunologic hydrops fetalis occurring during a nine-year period were reviewed. The pregnancies were complicated by hydramnios (78%) and preterm delivery (84%). Hydramnios appears to be the most useful indicator of the pregnancy at risk; its occurrence should prompt ultrasonographic investigation for evidence of hydrops. Modalities available for antenatal diagnosis of underlying fetal abnormalities include amniocentesis, serologic tests, fetal cardiac monitoring, radiography, hemoglobin electrophoresis and glucose tolerance testing. A specific cause for the hydrops may not be detectable (42% of our cases were idiopathic). Management of affected pregnancies is influenced by the frequent occurrence of fetal asphyxia and premature delivery. Outcome is poor: only 32% of the babies survived beyond the neonatal period. Symptomatic treatment for the neonate includes fluid restriction, maintenance of blood sugar, support of ventilation and attention to the complications of asphyxia.

The purpose of this study was to determine the bacterial growth inhibitory property of amniotic fluid (AF) from patients in the early third trimester and to examine its relationship to preterm labor and delivery. A total of 38 AF samples from patients between 27 and 35 weeks gestation with intact membranes were studied. Antibacterial activity was tested against Escherichia coli, Staphylococcus aureus, and Bacteroides fragilis. Fifteen fluids were from patients in preterm labor who delivered near term after successful inhibition of labor. Five of these fluids (33%) were inhibitory to E. coli, five (33%) to S. aureus, and 11 (73%) to B. fragilis. Nine fluids were from patients who failed inhibition of labor and delivered preterm; none of these were inhibitory to E. coli, two (22%) to S. aureus, and only one (11%) to B. fragilis (P less than 0.005). Two of the nine fluids from patients who failed inhibition of labor also yielded fusobacteria. The remaining 14 fluids were obtained from patients without preterm labor and exhibited antibacterial activity similar to that from patients with successful labor inhibition. Results suggest a relationship between the absence of AF antibacterial activity against B. fragilis and preterm delivery in patients with preterm labor and intact membranes.

A study was undertaken to determine why there is such variability in morbidity and mortality in neonates exposed to antenatal chorioamnionitis. Villous edema provides a clue. It was present in 72/83 placentas with chorioamnionitis. The extent and severity of the edema had a strong, positive correlation with cord arterial blood pH values, low Apgar scores, the need to resuscitate vigorously at birth, the subsequent need for assisted ventilation, the frequency of hyaline membrane disease, and neonatal mortality. Most of the difference in morbidity and mortality between preterm and full-term infants was related to the greater severity and extent of villous edema in those born prematurely.

Changes in the distribution of portal venous blood flow to the left and right lobes of the liver and through the ductus venosus were determined from before birth through 9 days of age in 25 chronically catheterized fetal and newborn lambs. Blood flow distribution was calculated by means of the radionuclide-labeled microsphere technique. With umbilical cord clamping portal venous blood flow distribution to the right lobe of the liver decreased when compared to that in the term fetus; distribution to the left lobe and ductus venosus increased. More than 50% of portal blood flow was shunted through the ductus venosus during the first hour after birth. Ductus venosus shunts of at least 25% of total portal blood flow were noted in half the lambs between the second and sixth days of life. Portal venous distribution to the right lobe was inversely related to the fraction of portal blood flow shunted through the ductus venosus. The ratio of right lobe weight to total liver weight was significantly correlated with the ratio of right lobe flow to total liver flow (r = 0.73; P less than 0.001). The conclusion is that large and persistent ductus venosus shunts are normal during the first postnatal week in lambs.

We studied the vascular reactivity of the systemic and uterine circulations of six pregnant sheep. We placed catheters in a maternal carotid artery and a jugular vein, and then implanted an electromagnetic flow transducer around the uterine artery of the pregnant horn. After allowing 3 days for recovery from anesthesia and operation, we measured mean arterial blood pressure, heart rate, uterine blood flow, and calculated uterine vascular resistance, then separately infused angiotensin and norepinephrine in each ewe at the rate that produced a 20 torr pressor response. Dexamethasone, 0.2 mg. per kilogram of body weight, was then injected intravenously daily for 2 to 4 days. On the day following the final injection of dexamethasone, we separately infused angiotensin and norepinephrine at a rate that, before steroid treatment, produced a 20 torr pressor response. Administration of dexamethasone for 2 to 4 days did not change mean arterial blood pressure, heart rate, uterine blood flow, or uterine vascular resistance. Prior to steroid treatment, angiotensin increased blood pressure, decreased heart rate, but had no consistent effect on uterine blood flow or uterine vascular resistance; norepinephrine increased blood pressure without chenging heart rate, decreased uterine blood flow, and increased uterine vascular resistance. The changes produced by angiotensin and norepinephrine were the same after dexamethasone treatment. These studies indicate that dexamethasone does not influence systemic and uterine vascular reactivity during normal sheep pregnancy.

A case of susceptibility to malignant hyperthermia, diagnosed by muscle biopsy during the first trimester of pregnancy, is presented. Pertinent medical history that might raise this suspicion is reviewed. The pathophysiology of malignant hyperthermia is discussed. Recent reports documenting the placental transfer of dantrolene and complications associated with dantrolene administration during labor are described. The pharmacology of dantrolene sodium is presented. Guidelines regarding the management of labor and delivery in patients susceptible to malignant hyperthermia are outlined. Suggestions for counseling patients and their children with this syndrome are reviewed.

Erythropoietin and granulocyte-macrophage colony-stimulating factor (GM-CSF) stimulate the differentiation and proliferation of erythroid cells. To determine the cellular mechanism of action of these growth factors, we measured changes in intracellular free calcium concentration [( Cac]) in single human erythroid precursors in response to recombinant erythropoietin and GM-CSF. [Cac] in immature erythroblasts derived from cultured human cord blood erythroid progenitors was measured with fluorescence microscopy digital video imaging. When stimulated with erythropoietin, [Cac] in the majority of erythroblasts increased within 3 min, peaked at 5 min, and returned toward baseline at 10 min. The percentage of cells that responded to erythropoietin stimulation increased in a dose-dependent manner. Additional stimulation with GM-CSF in cells previously exposed to erythropoietin resulted in a second [Cac] increase. Immature erythroblasts treated with GM-CSF followed by erythropoietin responded similarly to each factor with a rise in [Cac]. The source of transient calcium is intracellular since erythroblasts were incubated in medium devoid of extracellular calcium. Our observations suggest that changes in [Cac] may be an intracellular signal that mediates the proliferative/differentiating effect of hematopoietic growth factors.

A characteristic feature of histologic chorioamnionitis caused by ascending infection is the amniotropism displayed by polymorphonuclear leukocytes in the placental membranes. We tested the hypothesis that amniotic fluid from patients with histologic chorioamnionitis and intact membranes without clinical infection contains leukoattractants detectable by an in vitro leukotactic assay. Leukoattractants were detected in 13 cases (87%) and absent in 2 cases (13%) with histologic chorioamnionitis (p < 0.005). The two cases with histologic chorioamnionitis that had negative leukotaxis were classified as stage I/mild severity. A positive leukotactic response was a better predictor of histologic chorioamnionitis (87%) than positive Gram stain (33%), amniotic fluid culture (53%), gas-liquid chromatography (40%), or a combination of these three methods (60%). These results suggest that demonstration of leukoattractants in amniotic fluid is an earlier and more sensitive predictor of chorioamnionitis than is presently available. (Am J Obstet Gynecol 1989;161:802-7.)

Preterm birth is the leading cause of perinatal mortality and morbidity despite the technological advances in neonatology and maternal-fetal medicine. Risk factors have been tabulated that can help identify the woman at risk for preterm birth. Past medical history, present pregnancy events, and demographic/environmental characteristics can help the practitioner select women who need special care to help prevent or reduce the effects of premature delivery. Recently, new concepts of risk have been identified through research, and emphasis needs to shift from intervention to prevention of the low birth weight infant. Past and present management of premature labor is discussed. New research protocols are presented. Strategies for nurses working in family planning or obstetrical areas are discussed, demonstrating areas for interventions from a prevention-oriented nursing base.