Postpartum Uterine-Artery Velocity Waveforms in Women with Sickle Cell Disease

Abstract

Objective: To investigate the changes in uterine Doppler velocimetry during the postpartum period in women with homozygous sickle cell (SS) disease and to correlate these findings with values in the third trimester and with neonatal outcomes. Methods: We studied the postpartum changes in uterine Doppler velocimetry in 16 women with SS disease in relation to third-trimester systolic/diastolic (S/D) ratios and neonatal outcome. All patients had repeated measures of uterine S/D ratios biweekly in the third trimester from 28 weeks of pregnancy until delivery, and at 24 h, and 3 and 6 weeks postpartum. Results: Overall the mean S/D ratio in the first 24 h for these 16 women was 2.72 ± 0.72 and increased progressively to a mean S/D ratio of 6.88 ± 0.96 at 6 weeks postpartum, with the reappearance of a diastolic notch by the 3rd postpartum week. Twelve women who had normal (≤2.6) uterine S/D ratios during pregnancy delivered appropriate-for-gestational-age (AGA) infants. The remaining 4 women had abnormal uterine S/D ratios, and in 3 of these pregnancies, small-for-gestational-age (SGA) infants were delivered. The mean S/D ratios for the subgroups with abnormal value at each of the three postpartum periods were significantly higher than for the 12 SS patients with normal third-trimester values. Postpartum S/D ratios for the 3 women with SGA births were also significantly higher at 24 h and 6 weeks postpartum when compared to SS patients with AGA infants. Conclusion: We concluded that postpartum S/D ratios are higher in women with SS disease that have abnormal values in the third trimester and that they are associated with SGA births. In SS patients the nonpregnant pattern of uterine artery velocity waveforms which reappears postpartum may reflect an increase in the uteroplacental circulatory impedence due to reversal of the alterations in the spiral arteries induced by trophoblastic invasion during pregnancy or subinvolution of the placental bed. Additional studies are needed to further elucidate these important hemodynamic changes in women with hemoglobinopathies and to identify patterns predictive of neonatal outcomes in these high-risk patients.