Perinatal features of pregnancies complicated by nuchal cord.

The perinatal data of 550 fetuses with a nuchal cord at delivery were compared with those of a control group matched for gestational age, maternal age, and parity. The study group was subsequently subdivided into those fetuses with either single or multiple coils of nuchal cord. No significant differences were found in the comparison of routine ultrasound data between the two groups. The perinatal mortality rate and the prevalence of arterial pH less than 7.16, venous pH less than 7.20, and Apgar scores less than 7 at 5 and 10 minutes were similar in both groups. There was a significantly higher incidence of Apgar score less than 7 at 1 minute, meconium-stained amniotic fluid, emergency cesarean section, need for neonatal resuscitation, and of admission to the neonatal intensive care unit in the nuchal cord group compared with the controls. Multiple looping of the umbilical cord around the fetal neck was the main factor accounting for the higher incidence of these complications and the only explanation put forward for the three perinatal deaths that occurred in this group, all of whom presented in the preceding week with decreased fetal movements. The results of the present study suggest that sonographic identification of nuchal cord may be an important observation during third trimester sonography, particularly when evaluating cases of decreased fetal movements.