Comprehensive fetal ultrasonographic growth measurements in triplet gestations.

OBJECTIVE: Our purpose was to create tables and graphs of ultrasonographically derived fetal growth parameters in longitudinally studied triplet gestations from a single center. STUDY DESIGN: All triplet pregnancies managed by our division from 1987 through 1998 were identified. All had first-trimester dating sonograms and complete obstetric sonograms obtained by means of 3.5- or 5.0-MHz curvilinear transducers with freeze-freeze capability and on-screen calipers. Sonograms to assess fetal growth were obtained every 2 to 4 weeks, from 16 to 18 weeks' gestation until delivery. Fetal parameters obtained with each sonogram included biparietal diameter; head circumference; bicerebellar diameter; abdominal circumference; femur, humerus, tibia, and fibula lengths; estimated fetal weight; and head circumference/abdominal circumference ratio. Regression analysis was performed with JMP and Cricket Graph software packages, and lines of best fit with 95% confidence intervals were generated. RESULTS: A total of 443 ultrasonographic examinations were performed for 33 triplet pregnancies (99 fetuses). Each had between 3 and 6 sonograms obtained, all between 16 and 35 weeks' gestation. Scatterplots of each of the fetal growth parameters against gestational age were created with regression lines of best fit and 95% confidence intervals. All growth parameters were dependent on gestational age. CONCLUSION: A comprehensive set of fetal growth measurements in triplets from the United States is now available and can be used to assess longitudinal fetal growth.

Maternal serum screening for fetal trisomy 18: a comparison of fixed cutoff and patient-specific risk protocols.

OBJECTIVE: To compare the effectiveness of two widely used protocols for second-trimester screening for fetal trisomy 18. METHODS: Second-trimester screening results for 41,565 women were reviewed to determine whether pregnancies could be considered to be at high risk for trisomy 18. The screening test was considered positive if either maternal serum concentrations of alpha-fetoprotein (MSAFP), hCG, and unconjugated estriol (E3) fell below defined levels, or the second-trimester patient-specific risk (based on maternal age and serum analytes) was greater than 1:100. Detection rates, false-positive rates, and pregnancy outcomes for the two protocols were compared. RESULTS: The fixed-cutoff method showed a 23% detection rate and a 0.19% false-positive rate for trisomy 18. These low rates were in close agreement with a theoretical expectation for fixed-cutoff trisomy 18 screening. The risk-based approach resulted in a 69% detection rate and a 0.45% false-positive rate. Both methods identified pregnancies with other fetal anomalies. CONCLUSION: Overall, the risk-based method is more effective than the fixed-cutoff approach to trisomy 18 screening.

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.

Resolution of human parvovirus B19-induced nonimmune hydrops after intrauterine transfusion.

Our objective is to report our experience with cases of prolonged recovery from nonimmune hydrops secondary to human parvovirus B19 infection occurring after intrauterine transfusion. We reviewed cases referred to our unit over a 10 year period for exposure to parvovirus B19 infection. Those cases with serologic evidence of recent infection were identified. The cases requiring intrauterine transfusion were reviewed for demographic details, time of exposure, parvovirus B19 serology, gestational age at detection of nonimmune hydrops, number and results of fetal blood samples, duration from intrauterine transfusion to resolution of hydrops, and neonatal outcome. Of 38 cases identified through serologic evidence of recent parvovirus B19 infection, 35 (92.1%) did not develop hydrops, and these were followed by serial ultrasonography for 8 weeks from the time of exposure. Three cases (7.9%) developed hydrops and required intrauterine transfusion; in two the transfusion was intravascular and in one it was intraperitoneal. The mean duration from intrauterine transfusion to resolution of hydrops was 8 weeks 2 days. Pregnancy outcome in all cases was normal. In cases of nonimmune hydrops secondary to parvovirus B19 infection, resolution of the hydrops after intrauterine transfusion may take up to 12 weeks with a normal pregnancy outcome.

Fetal seizures: further observations.

BACKGROUND: Previous reports of ultrasonographically diagnosed seizure activity in utero have described fetuses with obvious, gross, tonic-clonic movements of trunk and extremities. CASES: Three fetuses with akinesia deformation sequence are described: two with arthrogryposis multiplex congenita and one with Pena-Shokeir syndrome. Each was demonstrated by serial real-time ultrasound examinations to have joint contractures, absent fetal breathing motions, and lack of gross movements other than sonographically evident subtle seizure activity. CONCLUSION: Fetal seizure activity can be subtle when seen in the presence of fetal anomalies that limit joint movement. The prognosis remains poor.

Clinical chorioamnionitis is not predicted by umbilical artery Doppler velocimetry in patients with premature rupture of membranes.

Chorioamnionitis substantially increases fetal and neonatal morbidity. Infants born to women with chorioamnionitis have a fourfold increase in neonatal morbidity. If this condition could be predicted before the clinical manifestation and thereby treated earlier, an improved perinatal outcome might reasonably be expected. Based on the in vitro model of bacteria-induced vasoconstriction and pulmonary hypertension noted in sheep and lambs after exposure to the spent medium of a bacterial culture, we theorized that infected amniotic fluid may produce vasospasm of umbilical and placental vessels, reduce fetal perfusion, and increase perinatal asphyxia, morbidity, and mortality. Umbilical vessel vasospasm may be detected by measuring the systolic-diastolic ratio (S/D) of the umbilical artery. Continuous Doppler flow studies of the umbilical artery S/D were performed prospectively on 51 patients with premature rupture of membranes who were not in labor. The most recent test, done within 1 day of delivery, was compared with pregnancy outcome. Ten subjects developed clinical chorioamnionitis, of whom none had an abnormal S/D. Six of 41 women without clinical chorioamnionitis had abnormal S/Ds. These data do not support the use of Doppler measurement of the S/D as a predictor of clinical chorioamnionitis.

Prenatal ultrasonographic fetal iliac bone measurement. Correlation with gestational age.

The variety of circumstances under which ultrasound examinations are performed makes fetal iliac bone measurement an important indicator of gestational age. We studied 322 well-dated pregnancies from 13 to 40 weeks' gestation with sonogram measurements of the fetal iliac bone in order to examine the relationship between gestational age and bone length. The results indicate a linear relationship, as described by the equation iliac length = -0.376 + (0.0887) (gestational age). The fit of the data to a straight line was quite close (R2 = .877, P = .0001). The data were used to obtain a nomogram for growth of the fetal iliac bone.

Crouzon syndrome: prenatal ultrasound diagnosis by binocular diameters.

This is a report of second-trimester prenatal diagnosis of Crouzon syndrome suggested by binocular and interorbital diameter measurement and family history. Early prenatal diagnosis provides the option of termination or optimal postnatal management for families who choose to continue the pregnancy.