Amniotic fluid lamellar body count: cost-effective screening for fetal lung maturity.

OBJECTIVE: To create a highly specific cascade testing scheme for fetal lung maturity using the lamellar body count, lecithin/sphingomyelin ratio (L/S), and phosphatidylglycerol. METHODS: A nondedicated hematology analyzer (Sysmex NE 1500, Toa Medical Electronics, Los Angeles, CA) was used to determine the lamellar body counts of 209 unspun amniotic fluid specimens. Maximally specific lamellar body count cutoffs for biochemical maturity and immaturity were determined using receiver operating characteristic curves. Biochemical lung maturity was defined as either a mature L/S ratio or phosphatidylglycerol. Biochemical lung immaturity was defined as both an immature L/S ratio and an immature phosphatidylglycerol. RESULTS: A lamellar body count of less than 8000 (n = 17) was 100% specific for biochemical lung immaturity (positive predictive value = 100%, negative predictive value = 86%). A lamellar body count of greater than 32,000 was 98% specific for biochemical lung maturity (positive predictive value = 99%, negative predictive value = 63%). CONCLUSION: Testing only specimens where the lamellar body count was greater than 8000 and less than or equal to 32,000 for the L/S ratio and phosphatidylglycerol would preclude the need for 76% of all L/S and phosphatidylglycerol assays. Because the lamellar body count is quick, simple, and universally available, it could serve as an extremely cost-effective screening test for fetal lung maturity.

Prenatal diagnosis of left ventricular aneurysm in the late second trimester: a case report.

Fetal echocardiography in a 24-year-old woman at 24 weeks' gestation demonstrated a left ventricular aneurysm and pericardial effusion. The patient was treated with oral digoxin followed by intensive antepartum monitoring. Intrauterine fetal demise occurred at 31 weeks. The autopsy confirmed the presence of an apical left ventricular aneurysm. This is a rare congenital cardiac anomaly, which has been reported in only three prior cases. This represents the earliest prenatal diagnosis of this condition.

Northwestern University Twin Study X: Outcome of twin gestations complicated by gestational diabetes mellitus.

Existing data concerning the effect of gestational diabetes on perinatal outcome in twin pregnancies is scant. We hypothesized that altered carbohydrate metabolism would worsen perinatal outcome in twin gestation in a manner similar to singleton gestation. Thirteen twin pregnancies complicated by gestational diabetes mellitus were matched by gestational age at delivery to 13 twin pregnancies unaffected by gestational diabetes. Comparing infants of diabetic mothers to infants of control mothers, there was a trend of greater likelihood of respiratory distress syndrome, hyperbilirubinemia, and prolonged neonatal intensive care nursery admissions. Our experience suggests that altered carbohydrate metabolism in multiple gestations increases the potential for neonatal morbidity.

Is intrauterine transfusion associated with diminished fetal growth?

Studies in animal models and human pregnancies suggest that severe fetal anemia and/or replacement of fetal with adult blood result in decreased pH, increased base deficit, and hyperlactacidemia. Similar changes have been noted in growth-retarded, nonanemic fetuses, and we therefore hypothesized that isoimmunized fetuses requiring intrauterine transfusions might have diminished growth. We longitudinally studied growth patterns in 17 isoimmunized fetuses by noting biparietal diameter and head and abdominal circumference measurements at each transfusion. The distributions of these measurements above and below the 25th, 50th, and 75th percentiles derived from our general obstetric population were compared at the initial transfusion and the last ultrasonogram performed before delivery. Birth weights also were noted and their distribution around the 25th, 50th, and 75th percentiles was compared to the expected distribution. For each ultrasonographic parameter, the distribution of measurements at the last ultrasonogram before delivery was not significantly different from the distribution at the initial ultrasonogram. The birth weight distribution also was not significantly different than the expected distribution. Thus we were unable to demonstrate slowing of fetal growth in our severely isoimmunized pregnancies.

Awaiting cervical change for the diagnosis of preterm labor does not compromise the efficacy of ritodrine tocolysis.

We retrospectively studied 209 patients treated with ritodrine hydrochloride to determine whether change in cervical effacement or dilatation during a period of observation before therapy would result in decreased efficacy of ritodrine, as measured by delivery delays of 48 hours, 1 week, or until greater than or equal to 37 weeks' gestation; neonatal intensive care unit admission; and neonatal respiratory distress syndrome. Patients who were greater than or equal to 3 cm dilated on admission were at high risk of therapy failure by all outcome measures compared with patients less than 3 cm dilated. For patients less than 3 cm dilated on admission, there was no difference in outcome when patients treated for contractions only were compared with those treated after change in effacement or dilatation had been documented. We conclude that awaiting change in cervical effacement or dilatation to be more certain of the diagnosis of preterm labor will not compromise the efficacy of ritodrine tocolysis.