Comparison of pharyngeal aspirate and amniotic fluid surfactant composition.

Amniotic fluid and oropharyngeal aspirate lung maturity profiles obtained simultaneously at delivery in 16 patients are compared. The lecithin/sphingomyelin ratio was greater in oropharyngeal aspirates than in amniotic fluid (p less than 0.02). The percent phosphatidylinositol was greater in oropharyngeal aspirates than in amniotic fluid (p less than 0.03). The mean differences between percent phosphatidylglycerol were not significant. These findings were uninfluenced by the time interval between amniotic fluid and oropharyngeal sampling, gestational age, or neonatal weight. These data could explain the lack of sensitivity of the amniotic fluid lung maturity profile.

Preeclampsia associated with hemolysis, elevated liver enzymes, and low platelets--an obstetric emergency?

A study was undertaken of 27 patients with severe preeclampsia who had hemolysis, liver enzyme elevation, and thrombocytopenia as described by Weinstein. In addition to this triad, all patients exhibited the symptoms and signs of pregnancy-induced hypertension by which the diagnosis is usually established. These patients were admitted to the hospital for strict bed rest. Patients who showed evidence of rapid maternal or fetal deterioration were delivered promptly. The remainder were managed without immediate delivery and with the institution of magnesium sulfate to prevent eclamptic seizures. Patients were monitored closely, and amniocentesis was performed to ascertain fetal lung status. If the lungs were mature, the infant was delivered. Attempting to delay delivery until a lecithin: sphingomyelin (L:S) ratio was mature resulted in only two infants developing respiratory distress syndrome (RDS); both had L:S ratios of less than 1.5 and were delivered for maternal indications. Maternal condition rapidly improved within 72 hours of delivery, and there was no persistence of thrombocytopenia or elevation of liver enzymes. Immediate delivery of preeclamptic patients who have thrombocytopenia and elevated liver enzymes may not be warranted. These findings suggest that the syndrome of hemolysis, elevated liver enzymes, and low platelets is not a separate entity, but merely a cluster of signs seen in some patients with hypertensive disorders in pregnancy.

Vaginal pool phospholipids in the management of premature rupture of membranes.

Clinical utility of vaginal pool amniotic fluid assessment in premature rupture of the membranes was prospectively studied in 214 patients between July 1, 1978, and June 30, 1981. We used a policy of nonintervention in patients with premature rupture of the membranes prior to 36 weeks' gestation. Vaginal samples collected on admission and daily thereafter were analyzed for phospholipids. Patients underwent delivery for any one of these conditions: (1) presence of phosphatidylglycerol, (2) spontaneous labor, or (3) sepsis. One hundred sixty-seven patients had no phosphatidylglycerol initially. Thirty-six of these acquired phosphatidylglycerol, and none had respiratory distress syndrome. Eight patients underwent delivery because of signs of sepsis in the mother, but all infants of septic mothers survived. The newborn infants of 49 patients developed the respiratory distress syndrome, and among these there were six deaths, with no maternal deaths. We believe that these results confirm the value of phosphatidylglycerol in patients with premature rupture of the membranes, and that delay in patients from premature rupture of the membranes results in few infections and a significant decrease in the respiratory distress syndrome.

Comparison of amniotic fluid lung maturity profiles in paired vaginal and amniocentesis specimens.

Amniotic fluid was obtained by transvaginal amniocentesis from 27 pregnant women in the third trimester. Subsequent to amniocentesis, membranes were ruptured and vaginal pool amniotic fluid was taken by bulb aspiration. The samples were analyzed for lung maturity profile, consisting of the lecithin/sphingomyelin (L/S) ratio and the percentages of phosphatidylinositol and phosphatidylglycerol. The L/S ratio was higher in the vaginal pool than in the amniotic sac in 22% of the paired samples. Similarly, the percentage of phosphatidylinositol was greater in the vaginal pool than in the amniotic sac in 48%. Phosphatidylglycerol, however, is invariably present in the amniotic sac when it is detected in the vaginal pool. The possible usefulness of these results in the management of patients with premature rupture of membranes is discussed.

Clinical utility of fetal lung maturity profile.

The usefulness of the lung maturity profile in predicting the absence of respiratory distress syndrome (RDS) in the newborn was assessed in 356 patients with an obstetric indication for amniocentesis. Newborn infants delivered of mothers with a lecithin:sphingomyelin (L:S) ratio greater than 2.0, phosphatidylinositol at a level indicating maturity, and phosphatidylglycerol greater than 2% experienced no RDS. Twenty-six of 40 patients with studies indicating immaturity, in contrast, experienced RDS. Similarly, 20 infants who were predicted to be mature by L:S ratio but in whom no phosphatidylglycerol was present experienced a 40% incidence of RDS. In a small number of patients in whom the L:S ratio suggested that the fetal lung was immature, but in whom the phosphatidylglycerol level was greater than 2%, no RDS occurred. These results suggest that a mature lung profile is more valuable in predicting absence of RDS in the newborn than the L:S ratio alone. Certain conditions known to be associated with development of RDS in the newborn may be more accurately assessed by the presence or absence of phosphatidylglycerol in amniotic fluid. Although the series is small, it appears that the presence of phosphatidylglycerol even with an immature L:S ratio predicts that the newborn will be free of RDS.

Routine fetal heart rate monitoring in the antepartum period.

A total of 4517 successful antepartum nonstress tests (NST) was performed on 2003 high- (28%) and low- (72%) risk obstetric patients. Most patients were monitored from 32 to 34 weeks' gestation onward. A reactive NST was defined as 2 accelerations in 10 minutes--15 beats/min minimum amplitude; 15 seconds minimum duration. The test was repeated at the next visit in low-risk patients with reactive NST or in 1 week in high-risk patients with this response. Nonreactive tests were followed immediately by a stress test in high-risk patients, but only after repeat nonreactive NST within 24 hours in low-risk patients. About 88% of low-risk and 86% of high-risk patients demonstrated ractive NST only. Late decelerations during subsequent stress testing or labor, low Apgar scores, and perinatal deaths were more common in low-risk pregnancies than in high-risk pregnancies and more common in those with nonreactive NST than in those with reactive NST. High-risk/reactive NST babies, however, fared better than low-risk/nonreactive NST babies. Of the 16 perinatal deaths 6 died antepartum, 2 died in labor, and 8 died as neonates. Presumed asphyxia accounted for 6 deaths while significant anomaly accounted for 5; sepsis and trauma accounted for 2 each. In only 2 instances was a reactive NST followed by a death from apparent asphyxia. Routine NST testing appears to improve the resolution of maternal risk classification and may contribute to better perinatal outcome.

The dehydroepiandrosterone loading test. III. A possible placental function test.

The dehydroepiandrosterone loading test (DLT) has been used in a small population of normal and high-risk obstetric patients, to date, in an attempt to develop a dynamic test of placental function. In spite of its limited applications, it has shown reliability in discriminating, with statistical significance, between high-risk pregnancies that result in normally grown, undistressed infants, and high-risk pregnancies that result in infants showing signs of placental insufficiency. The present report expands the study population by presenting our data on 40 loading tests performed in 37 high-risk and normal obstetric patients. Results of 19 of these DLT's have been previously reported and are included herein for statistical analysis. The DLT utilizes an excess substrate load of dehydroepiandrosterone to assess the maximum capability of the placenta to convert it to estrogen. Although our previous report did not show false positive or negative results in the conversion rates, the present results (40 DLT's) found two (2 out of 17) false positives (12%) and two (2 out of 19) false negatives (11%). The highly significant correlation between DLT result and pregnancy outcome seen previously was preserved. In addition, the data of another five DLT's in four patients are presented. This group includes a pregnancy with a fetus with multiple congenital malformations, two patients with intrauterine fetal death, and a nonpregnant woman. The results are not included in the statistical analysis, but discussion of these results has interesting pathophysiologic implications.

Fetal heart rate acceleration in labor: excellent prognostic indicator.

This study explores the significance of fetal heart rate acceleration in labor. Fetal heart rate accelerations were studied in 1,677 monitored laboring patients. Fetal outcome was analyzed according to perinatal mortality rate. Apgar scores, and incidence of late deceleration. The presence of accelerations of the fetal heart rate during labor proved to be an excellent indicator of subsequent good fetal outcome.

Acute fatty metamorphosis of the liver: a report of two patients who survived.

Two patients with acute fatty metamorphosis of the liver of pregnancy who survived are presented. Clinical and pathologic features, possible etiologic factors, and principles of treatment are discussed. Both patients subsequently were allowed to become pregnant again, both had uncomplicated second pregnancies without evidence of liver disease, and both delivered healthy babies.

A physiologic model of the dehydroepiandrosterone to estrogen conversion system in the fetoplacental unit. I. Development.

A physiologic model of the dynamics of fetoplacental unit dehydroepiandrosterone (HDEA) to estrogen conversion is presented. A mathematical representation of this model is included. The model is used in Part II to determine the rate constant of DHEA to estrogen conversion and to successfully identify those fetuses in jeopardy from placental insufficiency within the population studied. This presentation permits critical comprehension of the model without extensive mathematical background.

A physiologic model of the dehydroepiandrosterone to estrogen conversion system in the fetoplacental unit. II. Preliminary clinical application--the dehydroepiandrosterone loading test.

A dehydroepiandrosterone (DHEA) loading test (DLT) is described. The results of 19 DHEA loading tests in as many third-trimester obstetric patients are presented. Analysis involves inspection of the raw data and the application of the physiologic model of the DHEA to estrogen conversion system described in the preceding paper (Part I). The DLT results show that within the population studied, the conversion rate of DHEA to estrogens is lower in patients with placental insufficiency than in normal patients (N = 5, p = 0.002) or in patients with various complications of pregnancy who deliver normally grown, undistressed infants (N = 6, p = 0.001). Routine clinical application must await more extensive evaluation to preclude the existence of forms of placental insufficiency not detected by this means, or normal states resulting in "false-positive" tests. These initial clinical results are intended primarily to demonstrate the potential clinical applicability of the physiologic model described in Part I.