153. Spiral arterial blood flow during pregnancy; a systematic review and meta-analysis

Abstract

Objectives To evaluate the physiological adaptation of blood flow in human uterine spiral arteries throughout the course of normotensive and hypertensive pregnancies based on existing literature. Methods A systematic literature review and meta-analysis on the change of arterial uterine spiral arteries, measured by Doppler ultrasonography, was conducted. Literature search was performed in Pubmed, EMBASE and Cochrane Library. The search was limited to papers published in English. Both first and second selection were performed by two independent researchers. Weighted means of the Doppler indices were calculated for the three pregnancy trimesters. Results Seven longitudinal prospective and four cross-sectional studies were included with publication dates ranging from 1995 to 2015. Ultrasound measurements were performed at certain gestational ages using transvaginal or transabdominal transducers. In normotensive pregnancies, pulsatility index (PI) decreased from 0.76 (95% CI: 0.65–0.86) in the first trimester to 0.51 (95% CI: 0.45–0.57) (p Conclusions PI and RI in uterine spiral arteries both decreased with advancing gestational age with the largest decrease between the first and second trimester. This is in concordance with previous histological hypertrophic decidual vasculopathy- and Doppler uterine artery findings. Longitudinal studies examining comprehensively the predictive value of spiral artery Doppler for hypertensive pregnancies are yet to be determined.