Does chorionic villus sampling compromise fetal umbilical blood flow?

A possible association of limb reduction defects with chorionic villus sampling (CVS) may be related to compromised umbilical blood flow from the trauma of the procedure. We hypothesized that because CVS may disrupt or compromise umbilical blood flow to the fetus, either by vasoconstriction, bradycardia, or emboli, we would detect these changes using Doppler velocimetry. A cohort of 21 consecutive consenting patients undergoing first-trimester elective CVS for prenatal diagnosis were entered into a prospective longitudinal study. Colour flow Doppler velocimetry was performed on fetal umbilical arterial blood flow immediately before and after CVS to measure the pulsatility index, fetal heart rate, per cent flow time, and maximum flow velocity. Measurements were obtained from three consecutive cardiac cycles in three different umbilical segments and averaged. Potentially confounding variables also recorded included gestational age, method of CVS, number of passes, number of aspirations, placental location, tissue sample size, and operator. Umbilical velocimetry values before and after CVS were compared using the paired t-test and showed no statistically significant differences. No differences were found when data were analysed by gestational age, sample size, method, number of aspirations, placental location, or operator. We were unable to detect any significant change in fetal umbilical arterial blood flow velocimetry or heart rate after performing CVS. Umbilical blood flow does not appear to be routinely compromised by CVS.

Pregnancy outcome after expectant management of premature rupture of the membranes in the second trimester.

Because management of premature rupture of the membranes (PROM) at or before 26 weeks is controversial, we examined maternal and perinatal outcome after expectant management of 44 pregnancies complicated by this problem. Mean gestational age at preterm PROM was 23.9 +/- 1.7 (SD) weeks. The latency period between preterm PROM and delivery ranged from 1 to 68 days, with a medium of 6. Of the patients, 54.6% delivered within a week of PROM, and 79.5% delivered by four weeks; 77.2% developed chorioamnionitis, but despite this high incidence, there was no maternal sepsis or pelvic thrombophlebitis, and no maternal surgery was necessary. Perinatal outcome was 60.5% neonatal survival, 54.2% perinatal survival and a stillbirth rate of 10.4%. Respiratory distress syndrome, bronchopulmonary dysplasia, sepsis and intraventricular hemorrhage were common types of neonatal morbidity. There was no pulmonary hypoplasia, and limb deformity was seen in only two neonates. Costs of expectant management in pregnancies complicated by second-trimester PROM were estimated, and a strategy to reduce cost is suggested.

Umbilical cord blood gases and mortality and morbidity in the very low birth weight infant.

Umbilical cord blood gas values and morbidity and mortality were correlated in 191 very low birth weight (VLBW) infants (500-1500 g). The mean umbilical arterial pH and base excess differed significantly between survivors and non-survivors. The presence of at least moderate acidosis (arterial pH 7.15 or lower) was related significantly to mortality, particularly in infants younger than 26 weeks. The mean cord blood gas values did not predict the presence or severity of hyaline membrane disease or intraventricular hemorrhage, but Apgar scores did. Bronchopulmonary dysplasia, neurologic sequelae, necrotizing enterocolitis, and sepsis also did not correlate with mean cord gas values, but neither did Apgar scores. Furthermore, the severity and type of acidosis did not relate to morbidity. Combining cord blood gases and Apgar scores did not help predict morbidity, which was not surprising because cord pH values correlated poorly with Apgar scores (all r values less than or equal to 0.26). We urge caution in interpreting cord gases as predictors of morbidity in the VLBW infant.