New predictors of early impaired placentation preceding miscarriage before 10 weeks of gestation in IVF pregnancies: A prospective study.

INTRODUCTION:In a recent study of 10,011 pregnant women, 95% of miscarriages occurred before routine ultrasound scan at 11-14 weeks. Our study aimed to identify early first trimester parameters which may predict miscarriage before 10 weeks of gestation for in vitro fertilization (IVF) pregnancies. METHODS:A cohort of 115 healthy IVF patients with a singleton viable embryo in early first trimester were studied in a tertiary university-affiliated medical center (April 2017-June 2018). Calculations included gestational age (GA); ultrasound evaluation of crown-rump length (CRL), mean gestational sac diameter (GSD) and volume (GSV), mean yolk sac diameter (YSD) and volume (YSV); fetal heart rate (FHR), mean uterine arteries pulsatility index (UtA-PI); and maternal blood placental protein 13 (PP13) levels. Patients were divided into three groups by GA; and early miscarriage versus ongoing pregnancy after GA 10 weeks. RESULTS:Early fetal loss occurred in 14.8% of patients; miscarriage group had higher discrepancy between calculated and measured GA (P < 0.001), lower GSD and GSV (P = 0.005 and P = 0.02, respectively), significantly different YSD and YSV, and lower GSD/YSD and GSV/YSV ratios (P = 0.001 and P = 0.003, respectively). UtA-PI/CRL ratio was higher in patients with miscarriage at GA 46-48 days and GA >48 days (P = 0.034 and P = 0.026, respectively). PP13/CRL ratio was higher in patients with miscarriage at GA >48 days (P = 0.041). DISCUSSION:In IVF pregnancies with live embryo at first ultrasound scan, high UtA-PI/CRL and maternal blood PP13/CRL ratios may indicate impaired placentation preceded early pregnancy loss. A larger cohort is needed to further verify these predictions.