Comparison of uterine artery Doppler measurements at 6weeks of pregnancy after IVF between pregnancies that resulted in miscarriage and ongoing pregnancies.

Abstract

To compare uterine artery pulsatility index (UTPI) at 6weeks of pregnancy following in vitro fertilization (IVF) and embryo transfer (ET) between clinical pregnancies that resulted in a miscarriage and those that were ongoing beyond 12weeks. A prospective observational study was conducted in an IVF unit at Prince of Wales Hospital, Hong Kong, between December 1, 2017 and December 31, 2019. UTPI was measured at 6weeks of pregnancy among women who conceived following IVF/ET. Among 153 participants, 22 (14.4%) had a miscarriage whereas 131 (85.6%) had an ongoing pregnancy beyond 12weeks. Median UTPI in pregnancies that ended in a miscarriage was significantly lower than those that progressed beyond 12weeks (2.1, IQR 1.9-2.4 vs 2.50, IQR 2.2-2.9, respectively; P<0.001). The likelihood of the pregnancy ending in a miscarriage when the UTPI was above the 75th percentile (>2.9), between the 25th-75th percentiles (2.2-2.9), and below the 25th percentile (<2.2) was 0%, 13.2%, and 27.7%, respectively (P=0.001). IVF pregnancies that resulted in a miscarriage were associated with reduced resistance to uterine artery blood flow at 6weeks of pregnancy.