Winston A. Campbell

The Fetal Biophysical Profile and Its Predictive Value

Six fetal biophysical variables--the nonstress test, fetal movements, fetal breathing movements, fetal tone, amniotic fluid volume, and placental grading (biophysical profile)--were assessed in 150 high-risk pregnancies during a 30-minute observation period. The predictive value of the nonstress test alone, biophysical scoring, and contraction stress test alone in the identification of the healthy fetus as well as the fetus in jeopardy are discussed. The relationships between individual variables and combinations of variables to the outcome of pregnancy, as reflected by abnormal intrapartum fetal heart rate patterns, meconium during labor, fetal distress, and perinatal mortality rate were determined. The biophysical profile of all hypoxic fetuses was analyzed. These data suggest that the biophysical profile is more accurate in the identification of the hypoxic fetus than any other single method; therefore, a new protocol including the biophysical profile for antepartum fetal evaluation is presented.

Management of parvovirus infection in pregnancy and outcomes of hydrops : A survey of members of the Society of Perinatal Obstetricians

OBJECTIVE Our purpose was to investigate the evaluation and management of parvovirus infection during pregnancy. STUDY DESIGN Surveys were mailed to members of the Society of Perinatal Obstetricians residing in the United States and Canada in July 1997. They were asked about their evaluation and management of parvovirus infection, including whether they repeated and confirmed serologic studies, what their initial and follow-up evaluations included, whether they had had any cases of parvovirus-associated hydrops in the past 2 years, and if so, what were the management and outcomes of the hydropic fetuses. RESULTS Surveys were mailed to 1623 members of the Society of Perinatal Obstetricians and 541 completed surveys were returned. Sixty-eight percent of the respondents repeated and confirmed serologic studies. Eighty-nine percent used ultrasonography in their initial management of pregnant patients with recent parvovirus infection, 7.5% used amniocentesis for polymerase chain reaction, and 2% used fetal blood sampling. The outcomes of the 539 cases of parvovirus-induced hydrops included spontaneous resolution in 34%, death without intrauterine transfusion in 30%, resolution after intrauterine transfusion in 29%, death after intrauterine transfusion in 6%, and pregnancy termination in 1%. Almost all cases of nonimmune hydrops reported occurred between 16 and 32 weeks. CONCLUSIONS Approximately one third of the cases of parvovirus-induced nonimmune hydrops resolved spontaneously, whereas 83.5% of hydropic fetuses transfused survived.

Management and outcomes of pregnancies complicated by human B19 parvovirus infection: A prospective study

During a large statewide outbreak of fifth disease in Connecticut in 1988, 39 pregnant women were identified who had serologic evidence of recent human B19 parvovirus infection. The patients were followed up prospectively with targeted fetal ultrasonographic examinations to detect signs of fetal hydrops. Of these 39 pregnant women, 37 had healthy infants and two patients had miscarriages. None of the fetuses developed hydrops. We propose that pregnant women exposed to B19 parvovirus be tested for evidence of IgG and IgM B19-specific antibodies and that targeted fetal ultrasonography be considered when IgM antibodies are found. Percutaneous umbilical blood sampling and intrauterine transfusion can be considered in cases of B19 parvovirus-associated hydrops and anemia. The overall fetal loss rate in this prospective follow-up group was 5%.

The fetal biophysical profile in patients with premature rupture of the membranes—An early predictor of fetal infection

A modified fetal biophysical profile (nonstress test, fetal movements, fetal breathing movements, fetal tone, amniotic fluid volume, and placental grading) was serially assessed in 73 patients who presented with premature rupture of the membranes and were not in labor. The last study before delivery was compared with the outcome of pregnancy. The relationships between individual variables and combinations of variables (biophysical scoring) and the outcome of pregnancy--as reflected by the development of chorioamnionitis and/or neonatal sepsis--were determined. These data suggest that the fetal biophysical profile is a useful tool for evaluating patients with rupture of the membranes. Rupture of the membranes by itself does not alter the biophysical scoring of the healthy fetus; however, a low biophysical score (less than or equal to 7) was a good predictor of impending fetal infection in patients with premature rupture of the membranes.

Monoamniotic twins: Improved perinatal survival with accurate prenatal diagnosis and antenatal fetal surveillance

OBJECTIVE Our goal was to report our 10-year experience with monoamniotic twins and to compare that experience with cases reported in the literature. STUDY DESIGN Records of all monoamniotic twin pregnancies managed at the University of Connecticut Health Center from March 1986 to August 1996 were reviewed. A MEDLINE search from January 1966 to August 1996 was performed, and each report was screened for accuracy of diagnosis. Only cases with umbilical cord entanglement of nonconjoined like-sex twins, the obstetricians confirmation at delivery, or pathologic confirmation of monoamniotic placentation were included. Data collected were as follows: birth outcome, gestational age at delivery, birth weight, gender, Apgar scores, hematocrit, cord knotting, and neonatal complications. Cases from the literature were divided into those with prenatal diagnosis and those without. RESULTS Thirteen monoamniotic pregnancies resulting in 26 infants who were born alive were managed at our center. The average gestational age at diagnosis was 16.3 weeks. All had antenatal fetal surveillance including serial sonograms and nonstress tests. The average gestational age and birth weight at delivery were 32.9 weeks and 1669 gm, respectively. Cord entanglement was noted in all cases, with knotting in 8 of 13. Two pairs of 26 newborns had evidence of twin-twin transfusion syndrome. Eight of 13 monoamniotic pregnancies were delivered because of nonreassuring results of nonstress test, two because of preterm labor, two electively because of lung maturity, and one because of intrauterine growth restriction. Two of the 26 infants died in the neonatal period, one of congenital heart disease and one of sepsis and asphyxia. The MEDLINE search revealed 96 articles with a total of 202 sets of monoamniotic twins. Comparison of cases (13 sets) with the historic control group without prenatal diagnosis (77 sets) showed a 71% reduction in relative risk of perinatal mortality. CONCLUSIONS With accurate prenatal diagnosis, intensive fetal surveillance, and appropriately timed delivery, perinatal survival of monoamniotic twins is improved; it was 92% in this series.

Relationship between fetal biophysical activities and umbilical cord blood gas values

In a prospective study of 62 patients undergoing cesarean section before the onset of labor a fetal biophysical profile assessment was performed within 3 hours before the cesarean section. The presence or absence of the individual fetal biophysical activities (fetal heart rate reactivity, fetal breathing movements, fetal body movements, and fetal tone) were correlated with umbilical cord blood gas and acid-base measurements (artery and vein). Fetuses with nonreactive nonstress test results or the absence of breathing had significantly lower cord artery pH, PO2 bicarbonate, and base excess measurements but not a significantly different PCO2 level as compared with fetuses that had these activities present. Fetuses with the absence of movements or tone had lower pH, PO2 bicarbonate, and base excess levels and higher PCO2 levels as compared with fetuses with the presence of movements or tone, respectively. These blood gas and acid-base differences were observed in both umbilical cord artery and vein. Subsequent analysis of the blood gas and acid-base measurements of the fetuses with compromised biophysical activities revealed that there are different levels of acidemia, hypoxemia, and hypercapnia at which the individual biophysical activities are compromised. These data suggest that the first manifestations of fetal hypoxemia and acidemia are nonreactive nonstress test results and loss of fetal breathing; in advanced acidemia, hypoxemia, and hypercapnia fetal movements and fetal tone are compromised.

Fetal weight estimation formulas with head, abdominal, femur, and thigh circumference measurements

Most current sonographic techniques for estimating fetal weight involve measurements of the head, abdomen, and femur length both alone and in combination. The value of the fetal thigh circumference measurement in addition to the head, abdominal, and femur length measurements has not been investigated previously. Eighty-nine patients were scanned within 72 hours of delivery, and the following ultrasonic fetal parameters were obtained in all fetuses: biparietal diameter, head circumference, abdominal circumference, femur length, and thigh circumference. With multiple stepwise regression analysis, the best-fit formulas were developed with one, two, three, four, and five parameters, respectively. The best results were obtained by combining measurements of all five parameters: biparietal diameter, head circumference, abdominal circumference, femur length, and thigh circumference. The mean error of this formula was 6%, the mean deviation 0.3%, and the SD 7.8%. These data suggest that the addition of thigh circumference to measurements of the head, abdomen, and femur length improves the accuracy of fetal weight estimates.

Preterm premature rupture of the membranes: A risk factor for the development of abruptio placentae

A retrospective study of 298 patients with preterm premature rupture of the membranes managed expectantly during a 3-year period investigated the association between preterm premature rupture of the membranes and abruptio placentae. Expectant management was associated with the development of abruptio placentae in 19 of these 298 patients (6.3%). The prevalence of abruptio placentae in the entire population during the same 3-year period was 2.7%, whereas in patients without preterm premature rupture of the membranes it was 2%. None of the patients developed clinical or laboratory evidence of disseminated intravascular coagulation and no infection (maternal or neonatal) was noted among the patients who had abruptio placentae. Patients with preterm premature rupture of the membranes and severe oligohydramnios (largest pocket less than 1 cm) seem to be at particular risk for developing this complication. These data suggest that abruptio placentae should be considered as one of the possible risks of expectant management in preterm premature rupture of the membranes.

Comparison of six different ultrasonographic methods for predicting lethal fetal pulmonary hypoplasia

Nomograms of six different ultrasonographic fetal parameters were established by studying uncomplicated, singleton pregnancies, with well-established dates, between 16 and 40 weeks of gestation. The studied parameters could reflect fetal lung mass and included the following: chest circumference (CC), chest area (CA), chest area minus heart area (CA - HA), chest circumference/abdominal circumference ratio (CC X 100/AC), chest area/heart area ratio (CA/HA), and chest area minus heart area divided by chest area ratio [(CA - HA) X 100/CA]. The effect of ruptured membranes on these six ultrasonographic parameters was assessed by studying patients who had premature rupture of the membranes of less than 1 weeks duration. It was found that premature rupture of the membranes is associated with increased frequency of CC, CA, and CA - HA measurements at or below the 5th percentile. However, in patients with premature rupture of the membranes all measurements were within the normal range for the three ratios. The efficacy of each of the six parameters was determined by studying 13 fetuses at high risk for development of lethal pulmonary hypoplasia. The (CA - HA) X 100/CA parameter had the best diagnostic accuracy (sensitivity 85%, specificity 85%, positive predictive value 83%, and negative predictive value 85%).

Second-Trimester Ultrasound Markers for Detection of Trisomy 21: Which Markers Are Best?

Objective To investigate which second-trimester ultrasound markers for aneuploidy are the most diagnostically efficient in detecting fetal trisomy 21. Methods All second-trimester genetic sonograms performed since November 1, 1992 for women at increased risk for fetal trisomy 21 were analyzed restrospectively. Statistical analysis included descriptive statistics, the test of proportions, and univariate and multivariable logistic regression analysis using trisomy 21 as the dependent variable and ten aneuploidy ultrasound markers as independent variables. Results There were 581 normal fetuses, 23 with trisomy 21 and four with other chromosomal abnormalities. When one or more abnormal ultrasound markers were present, the sensitivity and flase-positive rate for trisomy 21 were 87% and 13.4%, respectively. After adjusting for confounders, multivariate logistic regression analysis showed the best combination of ultrasound markers for detecting trisomy 21 to be nuchal fold thickening (relative risk [RR] 85.5; 95% CONFIDENCE INTERVAL [CI] 20.4; 95% CI 4.5, 92.1)). The model combining these three ultrasound markers yielded a sensitivity of 87% and a false-positive rate of 6.7%. Conclusion By using only three ultrasound markers (combination of nuchal fold thickening, pyelectasis, and short humerus) the false-positive rate is decreased from 13.4% to 6.7% without any compromise in the sensitivity (87%). The clinical usefulness of evaluating the various secondtrimester ultrasound markers needs to be evaluated in prospective studies.