Uterine artery blood flow velocity waveforms in pregnant women with müllerian duct anomaly: a biologic model for uteroplacental insufficiency.

ABSTRACT

OBJECTIVE: The purpose of this study was to determine whether there are demonstrable alterations in uterine artery blood flow in pregnant women with müllerian duct anomaly. STUDY DESIGN: Flow velocity waveforms obtained from the placental and nonplacental uterine arteries were studied at 18 to 24 weeks' gestational age in 15 pregnant women with müllerian duct anomaly and in 30 controls. The systolic/diastolic ratios were compared and correlated with the degree of placental laterality and perinatal outcome. RESULTS: Systolic/diastolic ratio in the uterine artery was abnormal in 80% of the cases and in 10% of controls (p < 0.0001). A completely lateral placenta was found in 10 of 15 women of the study group and only in 1 of the 30 controls (p < 0.0001). Women with müllerian duct anomaly had higher systolic/diastolic ratios in the nonplacental uterine artery than those with a normal uterus (median 4.3, range 2.0 to 7.4 vs median 2.8, range 2.0 to 4.0; p < 0.001). Twelve of 15 women of the study group had poor perinatal outcome compared with 4 of the 30 controls (p < 0.001). Among those women with poor perinatal outcome, 11 of 12 (92%) in the study group and only 1 of the 4 (25%) in the control group had an abnormal systolic/diastolic ratio in the uterine arteries (p < 0.05). CONCLUSION: There is a clear association between placental laterality and high systolic/diastolic ratio in the nonplacental uterine artery in pregnant women with müllerian duct anomaly who had poor perinatal outcome. This finding suggests that unilateral placental implantation could lead to functional exclusion of one uterine artery from the uteroplacental circulation and could explain pregnancy complications in women with developmental fusion defects of the uterus.