Hypercoiling of the umbilical cord and placental maturation defect: associated pathology?

Our objective was to determine whether there is an association between hypercoiling of the umbilical cord and placental maturation defect. From a database comprising 1147 cases, containing data on all placentas examined at our institution during the study period, we selected all cases with a gestational age of at least 37 weeks that exhibited hypercoiling of the umbilical cord (coiling density above the 90th percentile, n = 42); we also examined 2 matched controls for each case, one with hypocoiling and one with normocoiling. The mean number of syncytiocapillary membranes (SCM) per terminal villus was calculated. Presence of a placental maturation defect was defined as the mean number of SCM below the 10th percentile. Correlations were assessed using Spearman's rho. Relations between dichotomous variables were tested using logistic regression. Mean number of SCM per terminal villus (+/-standard deviation) was 1.25 +/- 0.65. Difference in mean between hypo- and hypercoiled cords was 0.37 (95% confidence interval [CI], 0.07 to 0.67). The correlation coefficient between mean number of SCM and umbilical coiling index (UCI, coils/cm) was -0.28 (P = 0.002). The odds ratio (OR) for placental maturation defect in presence of hypercoiling was 2.61 (95% CI, 0.75 to 9.12). The OR for fetal death was 132 (95% CI, 13.2 to 1315) in the presence of a placental maturation defect and 5.49 (95% CI, 1.02 to 29.6) in the presence of hypercoiling. The OR for indication of fetal hypoxia/ischemia was 12.3 (95% CI, 3.0 to 50.3) in the presence of a placental maturation defect and 3.2 (95% CI, 0.95 to 10.9) in the presence of hypercoiling. We found a trend toward placental maturation defect in the presence of hypercoiling and an inverse relationship between the mean number of SCM in the terminal villi and the UCI. We confirmed associations between fetal death and both a maturation defect and hypercoiling and found an association between histological indication of fetal hypoxia/ischemia and a placental maturation defect.