Ultrasound characteristics and pregnancy loss in bovine IVF-derived pregnancies

Abstract

We compared ultrasound characteristics during the first trimester of Girolando female bovine IVF gestations that reached term or not. Pregnant recipients (n = 35) were followed up by ultrasonography every 6 days from D37 up to D90 or until the fetal heartbeat ceased. Embryonic vesicle diameter (EVD), fetometry parameters crown rump length (CRL) and biparietal diameter (BPD), and fetal heart rate (FHR) were assessed in fetuses from recipients that completed gestational development (n = 30) (Control group) or experienced pregnancy loss (n = 5) (Pregnancy Loss group). Results were analyzed by ANOVA repeated measurements. A detection of embryonic vesicle was not possible at D31 in gestations that did not reach term. CRL was decreased in pregnancy loss group and differed at D37 (16.17 ± 0.30 vs 13.14 ± 0.77 mm, for control and pregnancy loss group, respectively) and D55 (46.13 ± 0.51 vs 41.88 ± 2.74 mm, for control and pregnancy loss group, respectively). BPD values were similar between groups. FHR decreased at D49 (181.52 ± 0.82 vs 164.75 ± 9.29 bpm, for control and pregnancy loss group, respectively) and D55 (175.41 ± 2.19 vs 150.80 ± 15.10 bpm, for control and pregnancy loss group, respectively) in early pregnancy losses. These findings indicate that embryonic vesicle, CRL and FHR monitoring of IVF-derived gestations at days 31, 37 and 55 could be useful to predict an increased risk of pregnancy loss.