Harvey A. Gabert

The effect of cesarean section on respiratory distress in the presence of a mature lecithin/sphingomyelin ratio

Three hundred and six amniocenteses were performed on 240 patients to determine the lecithin/sphingomyelin ratio. The indications were maternal diabetes mellitus, Rh disease, hypertension, placenta previa, repeat cesarean sections, unknown gestational age, and toxemia. Respiratory distress and hyaline membrane disease were predicated correctly in all cases. There were 104 vaginal deliveries and 136 cesarean sections in this study. There was no apparent indication that the mode of delivery had any bearing on the development of respiratory distress or hyaline membrane disease.

Renal disease in pregnancy.

Renal disease in pregnancy may be progressive but only rarely. The problems encountered that create maternal and fetal morbidity and mortality relate to the development of superimposed preeclampsia and renal failure. Diagnosis is important to differentiate the cause of renal pathology so that appropriate treatment can be undertaken. The use of medications in renal disease in the presence of hypertension is controversial; however, adequate therapy should be given if indicated. Most cases of renal disease in pregnancy do not require termination; however, counseling concerning pregnancy is needed initially or subsequently.

Ultrasonographic identification of the macrosomic fetus

Ultrasonographically determined biparietal diameter, femur length, abdominal circumference, and estimated fetal weight were analyzed with regard to their ability to predict the macrosomic newborn. Receiver operating characteristic curves were plotted for each of these variables. Estimated fetal weight was superior to biparietal diameter or femur length measurements in the identification of the overgrown fetus. Because of limitations of positive predictive values and sensitivities, application of these observations varies with the clinical setting in which they are used.

Abnormal maternal serum alpha fetoprotein and pregnancy outcome.

The objective was to assess the occurrence of miscarriages, low birth weight, and karyotype abnormalities found with low and elevated maternal serum alpha-fetoprotein (MSAFP) among women who had genetic amniocentesis performed. A retrospective study of 2,159 women who had MSAFP analysis prior to amniocentesis was conducted. Pregnancy outcomes were obtained from record review and physicians follow-up. Limits of MSAFP used in analysis were <0.5 adjusted multiples of the median (MOM) (lower levels) and >2.0 MOM (upper levels). Autosomal trisomy was found in 1.6% with low, 0.9% normal, and 0.6% with elevated MSAFP values. Sex chromosome abnormalities were present only in patients with normal MSAFP, [45X (n = 6), 47XXY (n = 2), 69XXX]. Of five open neural tube defects, four had elevated MSAFP and one had a normal value. Omphalocele was identified in four patients, two with normal and two with elevated MSAFP. Gastroschisis was found in one low and one elevated MSAFP. Amniotic fluid alpha-fetoprotein (AFAFP) values did not correlate with MSAFP values. Patients with low MSAFP levels had a greater prevalence of abnormal karyotype (19 of 249, prevalence = 0.076) than patients with an elevated MSAFP level (2 or 166, prevalence = 0.012 OR (odds ratio) = 0.20 (P value = 0.024) when unadjusted for maternal age, and OR = 0.09 (P value = 0.001) when adjusted for maternal age. Spontaneous abortion occurred more often in patients with elevated (4 of 166, or 4%) than normal or low (20 of 1948, or 1%) values of MSAFP (odds ratio 4.32, P = 0.020 when adjusted for maternal age). Birth weight below 2,500 g was present less frequently with low or normal MSAFP (136 of 1,760, or 7.7%) than in elevated MSAFP (21 of 144 or 14.6%) (odds ratio 2.04, P = 0.005, unadjusted; and odds ratio = 2.32, P = 0.003, adjusted for maternal age). Female fetuses were present more often with low MSAFP (136 of 249, or 55%) than elevated levels 43% (71 of 164, or 43%; P = 0.024). We conclude that patients undergoing genetic amniocentesis with MSAFP <.5 MOM are less likely to miscarry, deliver a low birth weight newborn, or have a male infant than patients with MSAFP levels >2.0 MOM.

Fetal overgrowth. Diabetic versus nondiabetic.

Term, large for gestational aged newborns were retrospectively evaluated. The fetal parameter of relative growth, was measured using the ratio of fetal length to abdominal circumference (FL/AC). This measurement was not different between diabetic and nondiabetic gravidas who delivered LGA infants when ultrasound was obtained within 1 week of delivery.

Comparison of dynamic image and pulsed Doppler ultrasonography for the diagnosis of the small-for-gestational-age fetus

OBJECTIVE Because poor fetal growth is a significant cause of perinatal morbidity and mortality, a prospective study was undertaken to evaluate the ability of real-time ultrasonography and Doppler velocimetry to detect the small-for-gestational-age fetus. STUDY DESIGN A prospective study of 136 women at risk for fetal growth abnormalities was conducted. Patients were delivered within 3 weeks and had live-born, nonanomalous, singleton infants. The relative estimated fetal weight (estimated fetal weight divided by the median birth weight for gestational age) and the systolic/diastolic ratio were measured and compared with receiver-operator characteristic curves. In this method the area under the curve is the index of performance. RESULTS Forty-six infants were small for gestational age. Although both relative estimated fetal weight (area under the curve = 0.923) and systolic/diastolic ratio (area under the curve = 0.837) were significantly associated with the small for gestational age fetus, the former was more strongly correlated, p = 0.021. CONCLUSION Relative estimated weight is more sensitive and specific and should be the preferred parameter when gestational age is known.

A cross-sectional study of in utero growth of the above average sized fetus

In a cross-sectional study of 210 pregnancies resulting in above-average-sized term infants, biparietal diameter, femur length, and abdominal circumference were found to differ among three birth weight percentile groups (greater than 90, 76 to 90, and 51 to 75). Growth rates, however, were similar. Estimated fetal weights, derived from four formulas, showed the same pattern. Differences between large for gestational age infants and other above average sized infants exist; changes in growth are likely to have occurred before the thirty-third week of gestation.

Prospective comparison of the startle test (recoil) and non-stress test

Objective : Our purpose was to compare fetal heart rate reaction to external physical stimulation with the non-stress test (NST). Methods : This was a prospective study evaluating documentation of fetal heart accelerations by two methods. The standard NST was performed prior to the ultrasound evaluation. The NST results were not available to the ultrasonographer. M-mode ultrasound was used to establish a stable fetal heart rate. The ultrasound transducer was used to stimulate fetal movement by indentations of the uterus over the fetal small parts. A second fetal heart rate was determined within 15 s after stimulation. Results : A total of 122 patients had 159 studies performed. The fetal heart rate range due to fetal startle (recoil) was m 22 to 14 (median of 3) in the 45 fetuses with non-reactive NSTs and 1 to 38 (median of 15) in the 114 fetuses with a reactive NST ( p < 0.001). A receiver operating curve comparing the fetal response to the startle and the NST revealed an area under the curve of 0.972, consistent with high specificity and sensitivity. Conclusion : The fetal heart rate response to external stimulation correlates with the formal NST.

Estimating fetal weight in patients with preterm premature rupture of the membranes

Fetal weight estimation was performed in 58 women with preterm premature rupture of the membranes within 4 days of delivery. Of twelve formulas evaluated, only two met the requirements for clinical use (i.e., they had a small mean percent error and a high correlation). However, both had high random error, which may be attributable to the very low birth weights studied.

The startle test revisited

OBJECTIVE: Our purpose was to the compare fetal heart reaction to external physical stimulation with the nonstress test (NST).STUDY DESIGN: This prospective study evaluates documentation of fetal heart rate accelerations by two methods. The standard NST was performed prior to the ultrasound evaluation. The NST results were unavailable to the ultrasonographer. M-mode ultrasound was used initially to detect a stable heart rate. Then the ultrasound transducer was used to stimulate fetal movement by indenting the uterus over the fetal small parts. A second fetal heart rate was determined within 15 seconds after stimulation.RESULTS: A total of 194 patients underwent 235 studies. The patient population included four sets of twins. When the NST was reactive, 151/216 had an ultrasound startle response of ≥15 beats per minute; however, all nonreactive NSTs were associated with an ultrasound response of 14 beats per minute or less (p<0.001). A receiver-operating characteristic curve comparing the ultrasound fetal response to the startle with the NST identified the area under the curve to be 0.948, consistent with high specificity and sensitivity.CONCLUSION: The fetal heart rate response to external stimulation identifies 67% of patients with a reactive NST.