142. Maternal hypertensive disorders in pregnancy and the association with embryonic growth trajectories

Introduction Embryonic development is under the constant influence of the intrauterine environment. This environment is determined not only by genetic factors, but also by maternal health conditions. A strong association between hypertensive disorders (pre-eclampsia and pregnancy induced hypertension) and both intrauterine growth restriction and low birth weight have been described. However, these associations are mainly limited to second and third trimester foetal growth parameters and birth weight. The association between these hypertensive disorders of pregnancy and first trimester growth parameters have not been investigated yet. Objective/hypothesis In line with the findings on second and third trimester foetal growth, we hypothesize that embryonic (first trimester) growth is reduced in women with pregnancies complicated by hypertensive disorders. Methods Within a large population-based cohort in Rotterdam, The Netherlands, we assessed whether there is an association between maternal hypertensive disorders in pregnancy (both pregnancy induced hypertension and preeclampsia) and embryonic growth, defined as crown-rump-length (CRL) and embryonic volume (EV) using logistic regression analysis. Embryonic volume was measured using 3D ultrasound and virtual reality techniques, which enabled us to take this accurate parameter for embryonic growth into account. Results We included 1631 pregnancies in the analysis. In our first crude model, CRL has a statistically significant association with hypertensive disorders in pregnancy (p = 0.042). This accounts for a decrease of −0.22 SD CRL in women with a pregnancy complicated by a hypertensive disorder, compared to women without a hypertensive disorder. Discussion Our preliminary results suggest that embryonic (first trimester) growth is associated with hypertensive disorders in pregnancy. Additional analysis in which we adjust for confounding factors are currently being conducted. These will clarify the pathway through which embryonic growth is impaired. Moreover, the association with embryonic volume is being analysed, since this is a more accurate parameter for embryonic growth compared to the crown-rump-length.