A blueprint for academic obstetrics and gynecology.

A consensus conference sponsored by the Council of University Chairs of Obstetrics and Gynecology in February 1997 formulated the organization's response to the many external issues affecting academic medicine and obstetrics and gynecology including 1) a new practice model based on "wellness," 2) reimbursement changes that have jeopardized traditional revenue sources, 3) an emphasis on quality assurance based on outcomes research and evidence-based medicine, 4) the concept of lifelong learning dictated by an expanding knowledge base and new technology, 5) insufficient resources for basic and clinical investigation in obstetrics and gynecology, 6) workforce statistics indicating stabilization in the number of subspecialists, 7) the increasing diversity of the United States population. Recommendations were developed that are intended to foster change and contribute to the design of academic programs. These include appropriate training for residents as providers of primary care, with an emphasis on continuity clinics, an interdisciplinary curriculum in women's health for medical students; promotion of gender, racial, and ethnic diversity at all levels of medical education and academic leadership; creation of clinical trials research units; and the development of expanded opportunities for research in obstetrics and gynecology supported by the National Institutes of Health.

Gaucher's disease in pregnancy.

Gaucher's disease is an autosomal recessive lysosomal storage disease, resulting from a deficiency of the enzyme glucocerebrosidase, important for the physiologic recycling of cell membrane lipids. The clinical symptoms and disease presentations of Gaucher's disease are heterogeneous, including hepatosplenomegaly, bone "crisis" and fracture, anemia, thrombocytopenia and in some forms, rapid neurological decompensation. Similarly, the genetic variability of Gaucher's disease is diverse, and in some aspects affects phenotypic expression. Type 1 Gaucher's disease, however, usually present with less severe symptoms, at more advanced age, and is particularly amenable to enzyme replacement therapy with alglucerase. In type 1 patients with Gaucher's disease reproductive age is commonly reached and childbearing frequently desired with need for appropriate prenatal diagnosis, counseling and careful obstetrical surveillance. Although pregnancy concurrent with Gaucher's disease has been reported in the medical literature, only one small series of alglucerase treated Gaucher's disease during pregnancy exists. Without treatment, pregnancy concurrent with Gaucher's disease has several risks including an increased severity of anemia and thrombocytopenia that can potentiate postpartum bleeding, significant increases in organomegaly and possibly an increased spontaneous abortion rate. It is yet to be shown whether alglucerase reduces the risk of these complications during pregnancy and whether its use has any adverse effect on fetal development.

Fetal oxytocin and its extended forms at term with and without labor.

OBJECTIVE: We examined the concentrations of oxytocin and extended forms of oxytocin in umbilical plasma with and without labor. STUDY DESIGN: Umbilical venous and arterial blood were sampled in 27 term fetuses delivered vaginally and 13 delivered abdominally before labor. Extended forms and oxytocin were measured by radioimmunoassay and compared by analysis of variance or t test. RESULTS: Concentrations of extended forms were higher than oxytocin concentrations (24.7 +/- 3.1 vs 6.1 +/- 1.2 pg/ml, p < 0.01). Extended forms were higher in umbilical venous than in arterial plasma (29.6 +/- 5.0 vs 19.8 +/- 3.1 pg/ml, p < 0.05); oxytocin concentrations were not significantly different (4.7 +/- 1.6 vs 7.8 +/- 1.8 pg/ml). Concentrations of extended forms were markedly lower with than without labor (17.1 +/- 3.0 vs 37.1 +/- 5.7 pg/ml, p = 0.01). Ratios of extended forms over oxytocin decreased with labor. CONCLUSION: In umbilical plasma extended forms of oxytocin are more abundant than oxytocin. Extended forms originate in the uterus and decrease markedly with labor.

The predictive value of intrapartum fetal heart rate abnormalities in the extremely premature infant.

OBJECTIVE: Our purpose was to evaluate the validity of intrapartum fetal heart rate tracings in predicting short- and long-term outcomes of infants delivered between 24 and 26 weeks. STUDY DESIGN: Fetal heart rate tracings obtained during the last hour before delivery of fetuses delivered at 24 to 26 weeks' gestation were reviewed. Two perinatologists blinded to neonatal outcome evaluated the tracings for the following attributes: baseline rate and variability, presence and severity of decelerations, and overall impression (reassuring, nonreassuring, or ominous). Measured outcomes were cord blood pH; Apgar scores; intraventricular hemorrhage; duration of assisted ventilation; and hospitalization, survival, and developmental status at 1 year. RESULTS: The fetal heart rate attribute that was found to be predictive of neonatal outcome was the presence of any bradycardia or tachycardia found in any 10-minute window (designated "baseline rate abnormality"). This correlated with neonatal death (p < 0.007). None of the other fetal heart rate attributes were associated with any neonatal outcome. Intraobserver agreement was "fair to good" (kappa 0.5). CONCLUSION: Fetal baseline rate abnormalities (either tachycardia or bradycardia) were predictive of neonatal death in extremely premature fetuses.

Fetal renal pulsed Doppler waveform in prolonged pregnancies.

OBJECTIVE: Our purpose was to determine Doppler waveforms of the fetal human renal artery in prolonged pregnancy in the presence or absence of oligohydramnios. STUDY DESIGN: Fifty patients at or after 40 weeks were studied. Ultrasonography was performed to determine the amniotic fluid index by the four-quadrants technique. Two groups of patients were obtained on the basis of the amniotic fluid index. Group 1 had an amniotic fluid index > 5 (normal) (n = 33); group 2 had amniotic fluid index < or = 5 (oligohydramnios) (n = 17). Umbilical artery and fetal renal pulsed Doppler waveforms were determined and analyzed. The fetal renal artery systolic-to-diastolic ratio of the two groups was compared. RESULTS: Fetuses with a low amniotic fluid index had a significantly higher ratio. A significant negative correlation coefficient between amniotic fluid index and fetal renal systolic/diastolic ratio was found (r = -0.435 and p < 0.01). CONCLUSIONS: In prolonged pregnancies there is a significant relationship between the amniotic fluid index and the fetal renal systolic/diastolic ratio. In pregnancies associated with oligohydramnios the systolic/diastolic ratio is significantly higher than in those with normal amniotic fluid volume. These data suggest that intrarenal flow in prolonged pregnancies complicated with oligohydramnios is significantly different.

Validation of noninvasive fetal renal artery flow measurement by pulsed Doppler in the lamb.

OBJECTIVE: Our objective was to evaluate the accuracy of quantitative measurement of blood flow of the left renal artery in the fetal lamb by means of range-gated, two-dimensional pulsed Doppler ultrasonography. STUDY DESIGN: Doppler measurements were compared with invasive measurements obtained with a perivascular flow probe (Transonic) placed on the fetal renal artery. Renal blood flow was manipulated acutely either by volume expansion or depletion or by means of pharmacologic agents. With each manipulation values of the left fetal renal artery blood flow were obtained with both methods. The size of the fetal renal artery was determined by postmortem examination. RESULTS: A total of 36 paired flow measurements were obtained on five fetuses. One fetus had only Transonic determination of renal blood flow. Pulsed Doppler ultrasonography blood flow and transit-time ultrasonography blood flow estimations were correlated (F = 82.4, R2 = 0.73, p < 0.001). CONCLUSION: This study suggests that two-dimensional pulsed Doppler can reliably estimate renal blood flow in the fetal lamb.

Pregnancy outcome following ultrasound diagnosis of macrosomia.

Both elective cesarean and early induction have been proposed for pregnancies in which the fetus is suspected to be macrosomic by ultrasound examination. We studied 242 nondiabetic women with estimated fetal weights (EFWs) by ultrasound of at least 4000 g or the 90th percentile for gestational age at 36 or more weeks' gestation. In 66 of 86 women (77%) delivering within 3 days of ultrasound examination, EFW exceeded birth weight. In only 41 of these 86 women (48%) were the EFWs within the corresponding 500-g category of birth weight. A trial of labor resulted in vaginal delivery in 76 of 106 women (72%). There were five cases of shoulder dystocia but no birth trauma. Estimated fetal weights and birth weights were not significantly different between the women who had a trial of labor and those who did not. Our results do not support cesarean delivery or early induction as a means of preventing infant morbidity when fetal macrosomia (weight of 4000 g or more or the 90th percentile for gestational age) is diagnosed by ultrasound.

Low incidence of positive amnionic fluid cultures in preterm labor at 27-32 weeks in the absence of clinical evidence of chorioamnionitis.

In order to determine the utility of amniocentesis for detecting subclinical chorioamnionitis in asymptomatic afebrile women in preterm labor with intact membranes, we enrolled 47 women between 27-32 weeks' gestation in a prospective study. After enrollment, 38 women fulfilled all clinical and laboratory criteria for the study; nine women were excluded because they had a leukocyte count exceeding 15,000/microL. None of the 38 asymptomatic afebrile women had a positive culture from the amnionic fluid for bacteria, fungi, Mycoplasma hominis, Ureaplasma urealyticum, Chlamydia trachomatis, or any viruses. Sepsis was not proved in any of the 38 infants delivered to these patients. There was a clear relationship between histologic evidence of chorioamnionitis and failure of tocolytic therapy. Fetal lung profiles were mature in 29% of the amnionic fluid samples from 30-32 weeks' gestation, but in none of the amnionic fluid samples before 30 weeks. Amniocentesis does not seem useful to detect chorioamnionitis in asymptomatic afebrile women with preterm labor and intact membranes at 27-32 weeks' gestation, and should be reserved for those cases in which information about fetal lung maturity would be helpful.

Histologic chorioamnionitis and preterm delivery in different patient populations.

The placentas of 1843 deliveries were examined for the presence of histologic chorioamnionitis, which was classified as mild, moderate, or severe. Chorioamnionitis was present in 7.5% of patients who underwent cesarean before labor and in 18 and 32% of those delivering at term and preterm, respectively. Chorioamnionitis was severe in 74% of preterm but in only 15% of term deliveries. Premature rupture of membranes (PROM) was more frequent with preterm than with term delivery, with chorioamnionitis present in 42 and 15% of patients, respectively. Although chorioamnionitis was equally frequent in women with intact membranes delivering preterm and term, chorioamnionitis was severe in 63% of preterm and 14% of term deliveries (P less than .001). The frequency and severity of chorioamnionitis were related inversely to gestational age at preterm birth. Preterm delivery was more frequent in black than in white patients (19 versus 9%) and in indigent clinic versus private patients (13 versus 7.5%). However, there was no significant difference in frequency and severity of chorioamnionitis between black and white or between indigent clinic and private patients who delivered preterm. Among term births, chorioamnionitis was more often severe in black than in white patients. Chorioamnionitis in term deliveries was more frequent in clinic than in private patients; however, this was not true when only severe chorioamnionitis was considered. There were no differences in PROM between these patient populations. Thus, higher preterm birth rates in black and indigent clinic populations are not due to the more frequent occurrence of chorioamnionitis.

Preterm birth prevention: evaluation of a prospective controlled randomized trial.

Over a 3-year period 5457 indigent patients were scored for risk of preterm birth and 4595 women were delivered at greater than or equal to 20 weeks' gestation. Patients at high risk (18.1%) were randomized into control and intervention groups. The latter group received weekly cervical examinations and instruction regarding subtle symptoms and signs of preterm labor. Medical providers received similar instruction. There was no difference in preterm births between control and intervention groups (20.8% vs. 22.1%). Medical providers, convinced of preterm birth prevention during year 1 of the study, defeated the study design by giving preterm birth precautions to all patients. In turn, preterm births decreased from 13.7% (year 1) to 9.3% (year 2, p less than 0.001) and remained stable in year 3 (8.7%). Preterm births during year 1 and the 8 months preceding year 1 were not different. Significant differences in preterm births between private and indigent study patients during these two periods (p less than 0.001) disappeared during years 2 and 3 of the study.

Evaluation of risk scoring in a preterm birth prevention study of indigent patients.

A total of 4591 indigent patients were scored for risk of preterm labor and birth by the Creasy et al. scoring system and delivered at greater than or equal to 20 weeks' gestation. Of 462 preterm deliveries (less than 37 weeks), only 39.6% were contributed by the 18.1% of patients who scored at high risk (score greater than or equal to 10). Of the 44 risk factors in the scoring system, 25 were not statistically significant by univariate chi 2 analysis. The spontaneous preterm birth rate was 8.0%. The positive predictive value of the Creasy et al. system was 18.3%. With multiple logistic analyses we excluded infrequent risk factors and identified five factors that remained significant (prepregnancy weight less than 45.5 kg, black race, single marital status, one preterm labor and delivery, preterm labor, and delivery greater than or equal to 2). With these five risk factors we created an equation that allowed identification of 12% of patients at high risk of preterm delivery with a positive predictive value of 21.9%. Because of the importance of previous preterm delivery, risk scoring of primigravid patients is of limited value.

The clinical significance of hemorrhagic endovasculitis of the placenta.

Hemorrhagic endovasculitis of the placenta has been reported to correlate with intrauterine growth retardation, perinatal morbidity and mortality, and long-term developmental delay. At a regional obstetric hospital we identified 13 cases of hemorrhagic endovasculitis among 1938 placentas from singleton pregnancies of greater than or equal to 20 weeks' gestation over a 3-month period, an incidence of 0.67% of unselected pregnancies. All cases were live-births without intrauterine growth retardation. Associated clinical features were pregnancy-induced hypertension, nuchal cord at delivery, and postterm gestation. One infant had severe perinatal asphyxia with long-term psychomotor retardation. In the placenta, hemorrhagic endovasculitis was associated with infarction, fetal vessel thrombosis, and villitis of unknown cause. Interference with umbilical blood flow or regional compromise of villous perfusion may be an initiating event in the development of this lesion.

Kell sensitization in pregnancy.

Maternal anti-Kell antibody was found in 127 of 127,076 pregnancies during a 16-year period (0.1%). Thirteen Kell-sensitized pregnancies ended with a Kell-positive newborn infant, five of these had a poor perinatal outcome (hydrops, intrauterine or neonatal death, hemoglobin less than 7.9 gm, congestive heart failure). Mothers with Kell-positive infants and poor outcome had anti-Kell titers greater than or equal to 1:128 at delivery. With a maternal anti-Kell titer less than 1:32 at delivery, only one baby was Kell positive and mildly affected by hemolytic disease. Spectrophotometric analysis of amniotic fluid (delta optical density at 450 nm) in three of four pregnancies with poor perinatal outcomes revealed values of delta optical density at 450 nm in the high midzone of Liley within 1 week of delivery. Therefore, Kell-sensitized patients have to be managed differently from patients with rhesus sensitization. A management scheme to optimize perinatal outcome in Kell-sensitized pregnancy is described on the basis of this largest reported series of Kell-sensitized pregnancies.

Sonographically documented disappearance of fetal ascites.

Two patients with sonographically documented fetal ascites are described. Workup for immunologic or nonimmunologic causes was negative. Subsequent sonar examinations demonstrated disappearance of fetal ascites. At delivery, previous abdominal distention was apparent. Fetal ascites of unknown etiology in the late second trimester does not necessarily have a poor prognosis. Serial sonographic examinations are indicated for follow-up of fetal ascites.

Variable heart rate decelerations and transcutaneous PO2 during umbilical cord occlusion in fetal monkeys.

In five near-term monkeys under ketamine anesthesia, fetal heart rate, blood pressure, intrauterine pressure, and transcutaneous oxygen tension (tcPO2) were recorded continuously while the umbilical cord was occluded for 15 or 30 seconds. Fetal heart rate decreased 55 +/- 19 bpm, (mean +/- SD) and 78 +/- 20 bpm, respectively, with 15 and 30 second occlusions, while tcPO2 declined 6.0 +/- 1.6 and 11.5 +/- 3.3 torr, respectively. Fetal hypertension started promptly with cord occlusion and reached a maximum within 5 to 16 seconds; fetal blood pressure decreased thereafter and, in most instances, fell below the baseline until fetal heart rate began to recover. Fetal heart rate decreased within 1 to 2 seconds of cord occlusion, tcPO2 changes were the same, while heart rate changes were attenuated when the fetus was pretreated with 0.2 mg of atropine. These findings support a rapid and marked initial baroreceptor response, followed by a less marked chemoreceptor response. Thirty seconds following cord occlusion, PaO2 had returned to baseline, while tcPO2 was still 3 to 7 torr below baseline, indicating cutaneous vasoconstriction even though systemic blood pressure was normal. Relative heat output required to maintain the tcPO2 electrode temperature at 44 degrees C did not reflect alterations in skin perfusion during periods of cardiovascular change.

Portal venous blood flow distribution to liver and ductus venosus in newborn lambs.

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.

A comparison of terbutaline and ethanol in the treatment of preterm labor.

Ninety-two women in preterm labor were randomly assigned to either terbutaline or ethanol. In women with intact membranes, terbutaline was significantly more effective than ethanol in preventing progressive cervical dilation during the first 36 hours of treatment while betamethasone was given to the mother. Additionally, pregnancy was maintained significantly longer in women with intact membranes who were treated with terbutaline (15 +/- 4 days) rather than with ethanol (10 +/- 3 days). However, only 18% of women in each treatment group maintained their pregnancy beyond 36 weeks' gestation. In women with ruptured membranes and cervical dilation less than 4 cm, terbutaline was significantly better than ethanol in maintaining pregnancy for a minimum of 36 hours. Serious maternal side effects were not observed with terbutaline or ethanol, although a majority of women also received betamethasone. Neither drug caused serious adverse neonatal effects.

Comparison of continuous transcutaneous Po2 measurement with intermittent arterial Po2 determinations in fetal lambs.

This study determined the validity of transcutaneous Po2 (tcPo2) versus Pao2 determinations in the sheep fetus. In 7 fetal lambs catheters were placed in the carotid artery and the trachea, and ECG leads and a tcPo2 electrode were attached. Intermittently determined Pao2 values were compared to continuously recorded tcPo2 values. Fetal tcPo2 values ranging from 12 to 29 mmHg were achieved by changing the gas mixture the ewe breathed or by inflation of a balloon catheter in the maternal aorta. Transcutaneous Po2 correlated strongly with Pao2 (r = .91). These studies indicate that the tcPo2 electrode precisely and accurately reflects Pao2 in the fetal lamb. Limitations of tcPo2 measurements regarding prolonged attachment of the electrode to the fetal skin as well as fetal skin tolerance to the heat of the electrode have been identified. With this electrode the changes in oxygen tension can be compared with changes in fetal cardiovascular variables, eg, heart rate, blood pressure, and ECG, for a better understanding of the effects of hypoxemia on the fetus.