Antepartum diagnosis of noncoiled umbilical cords

The null hypothesis is that fetuses with noncoiled umbilical cords diagnosed in the antepartum period will have outcomes no different from those with normally coiled cords.

We prospectively gathered data from Jan. 1 through May 18, 1992, from all fetuses undergoing routine ultrasonographic evaluation. The outcomes of fetuses noted to have noncoiled umbilical cords were compared with those of a control group of fetuses with normally coiled cords. The control group consisted of those subjects undergoing ultrasonography during the study period who were ultimately transferred to our perinatal practice for the remainder of the pregnancy (i.e., the highest-risk patients). Two outcome parameters were selected for comparison: fetal anomalies and fetal death.

Six hundred eighty-seven consecutive ultrasonographic examinations were performed. Twenty-five subjects (3.7%) had noncoiled umbilical cords identified ultrasonographically (mean gestational age at diagnosis 20.3 +/- 3.5 [SD] weeks). The control group had 197 subjects. The combined incidence of fetal anomalies or death in the noncoiled group (16%) was significantly greater (p < or = 0.05, relative risk 4.6 [95% confidence interval 1.41 to 14.15]) than that of the control group (3.5%). The noncoiled group had two fetal deaths (8%), whereas two deaths (1%) occurred among controls (p < or = 0.05, relative risk 8 [95% confidence interval 1.16 to 50]). Two (8%) fetal anomalies (anencephaly, prune-belly syndrome) occurred in the noncoiled group, whereas the controls (n = 197) had five fetuses (2.5%) with anomalies (not significant).

The antepartum identification of noncoiled umbilical cords appears to be a risk factor for suboptimal pregnancy outcome.