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 -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.

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.

A prospective comparison of terbutaline and magnesium for tocolysis.

OBJECTIVE: To compare the tocolytic efficacy and side effects of parenteral and oral magnesium and terbutaline. METHODS: Ninety-eight patients in labor between 23-35 weeks were prospectively entered into a controlled trial of intravenous and oral magnesium versus subcutaneous and oral terbutaline. Tocolytic effectiveness was judged by delay of delivery for 48 hours or 1 week, and to 37 weeks or more. The need to change therapy to the alternate drug was identified, as were side effects. Entrance characteristics of the population, initial pelvic examination, and concomitant infection or cervicovaginal isolates were noted. Outcomes included gestational age at delivery, birth weights, and Apgar scores. Outcome analysis was based on initial tocolytic therapy. RESULTS: Significantly more patients in the magnesium group delivered at 37 weeks or more: 34 of 46 versus 27 of 52 (P < .05). No significant differences were found for delivery by 48 hours or 1 week. The interval between treatment and delivery was greater for magnesium: 7.1 +/- 3.9 versus 5.0 +/- 3.2 weeks (P < .005). Failure to achieve 37 completed weeks was more often due to obstetric complications than to preterm labor itself. Tocolytic effectiveness was reduced if secondary therapy or re-treatment was required or if the patient had cervical dilatation of 3 cm or greater. Infectious complications were common but were not associated with tocolytic effectiveness. Side effects were more noticeable with oral magnesium and subcutaneous terbutaline. CONCLUSIONS: For short-term tocolysis, no significant difference was found between magnesium and terbutaline. Magnesium was associated with a higher term delivery rate. Idiopathic preterm labor accounted for only a small part of the overall prematurity in the study population.

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.

Clinical chorioamnionitis is not predicted by an ultrasonic biophysical profile in patients with premature rupture of membranes.

A modified biophysical profile was assessed serially in 47 patients with premature rupture of membranes who were not in labor. This profile included fetal movement, fetal tone, fetal breathing, amniotic fluid volume, and placental grade. The most recent study, obtained within 2 days of delivery, was compared with pregnancy outcome as reflected by the development of chorioamnionitis and/or neonatal sepsis. No study patient received antibiotics, steroids, or tocolytics before labor. Neither the composite biophysical profile nor any of its components were found to be different between patients with and without clinical chorioamnionitis. Neonatal sepsis was not observed. These data do not support the use of the biophysical profile as a predictor of maternal infection.

Umbilical cord blood gas assessment of twins.

Umbilical cord arterial and venous blood gas values were compared in 63 twin pairs, of which 57 pairs had birth weights of 1500 g or more each. Small differences between the first and second twins existed for PO2, PCO2, and pH. However, bicarbonate values did not differ significantly. These cord gas differences represent minor respiratory aberrations, as reflected by a tendency toward carbon dioxide retention by the second twin. Route of delivery, time interval between deliveries, and nonvertex presentations were not associated with significant deviations from these observed acid-base patterns.

Umbilical cord blood gases for term healthy newborns.

Examination of paired umbilical arterial and umbilical venous blood gases for 147 term, healthy newborns revealed a strong correlation of pH, bicarbonate, and base excess with the 1-minute Apgar score. Although significantly different from each other, a strong correlation existed between the gas measurements of the two vessels. The lower limit of pH for the umbilical artery was 7.12 and for the vein, 7.25. The arterial-venous difference for bicarbonate but not pH, oxygen or carbon dioxide tension, or base excess was correlated with the 1-minute Apgar score.

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.

Fetal anthropometry at term: effect of menstrual age and relative fetal size.

In a study of 324 term pregnancies, fetal measurements (biparietal diameter, femur length, and abdominal diameter) obtained within one week of delivery correlated more strongly with relative birth weight than with menstrual age.

In utero growth of the large-for-menstrual-age fetus.

In a cross-sectional study of 87 large-for-menstrual-age term infants, intrauterine growth was found to be linear, 34 g per day. Differences between diabetic and nondiabetic pregnancies were not evident.

History and development of cesarean operation.

The history of cesarean birth has developed in spite of myths, physician differences, and early patient deaths and morbidity. The methods used today prevent maternal deaths and morbidity, and the cesarean operation is one of most common surgical procedures.

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.

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.

Fetal weight estimates in diabetic gravid women.

Fetal weight in utero was estimated sonographically within one week of delivery in 70 live-born fetuses of diabetic gravidas. The best estimates of weight were obtained with formulas dependent on biparietal diameter, abdominal circumference, and femur diaphysis length, and with formulas using the two variables of femur diaphysis length and abdominal circumference. Use of a special formula for the fetus of a diabetic mother was not of additional benefit. Acceptable weight estimates for the macrosomic diabetic fetus were not obtained.

Premature placental calcification in maternal cigarette smokers.

Ultrasonographic examinations, including placental grading, were done in 145 smoking and 100 nonsmoking low-risk obstetric patients at 37 weeks' gestation. Extensive calcification--grade III changes--occurred significantly more often in smokers than in nonsmokers (36 versus 14%; P less than .0001). Two groups of smokers, consuming five to 15 cigarettes per day or one or more packs per day, also had significant differences in grade III placenta when compared with nonsmokers. Smokers under age 20 years were more likely to have premature grade III changes; however, parity did not influence premature placental calcification in smokers and nonsmokers. The incidence of small for gestational age infants delivered was not significantly higher in smokers, and grade III placental changes appeared to occur no more often in SGA infants of smokers than of nonsmokers. Our findings suggest that the smoking gravida is at increased risk for premature placental calcification.

Estimated fetal weight: applicability to small- and large-for-gestational-age fetus.

Ultrasonic formulas using femur length and abdominal circumference with or without biparietal diameter were found to be highly accurate in predicting the weight of normal-sized term infants. The small-for-gestational age fetus, however, was overestimated and the large-for-gestational-age fetus was underestimated. The fetal weight formulas tested that were appropriate for the entire study group were not applicable to those fetuses having altered growth.

The relationship of placental grade to fetal size and growth at term.

Among 246 term patients undergoing ultrasonic evaluation within 1 week of delivery, a grade-three placenta was found in 39.4%. Advanced placental maturity was not associated with altered fetal growth rates or an increase in small- or large-for-gestational infants. At term, advanced placental maturity is not associated with aberrant fetal growth.