Doppler velocimetry, placental morphology and outcome in insulin-dependent diabetes

The purpose of this study was to determine the underlying cause of abnormal umbilical artery Doppler velocimetry in pregnancies complicated by insulin-dependent diabetes, by evaluating placental morphology and correlating Doppler results with pregnancy outcome. Our study population consisted of 14 pregnancies with normal Doppler results and 11 pregnancies with abnormal Doppler results. Quantitative placental examinations were performed. Maternal and perinatal characteristics were analyzed. Infants from the abnormal Doppler group had a statistically significantly higher incidence than those from the normal Doppler group of hyperbilirubinemia, Cesarean delivery for fetal distress, and neonatal intensive care stay of 2 or more days. Women with abnormal Doppler results delivered earlier (36 vs. 38 weeks) and had infants of lower birth weight (3079 vs. 3629 g). They were also three times more likely to have poor glycemic control (relative risk = 3.2; p = 0.0067). The placentae of both groups showed no statistically significant differences in placental weight, number of tertiary stem villi, number of small muscular arteries, or mean arterial width. Our findings suggest a functional rather than structural placental process as the cause of the abnormal Doppler results in pregnancies complicated by diabetes. An association between glycemic control and Doppler velocimetry is suggested.