Impact of the mode of conception on gestational hypertensive disorders at very advanced maternal age

Research question: To study gestational hypertensive disorders in oocyte donation pregnancies compared with other modes of conception at very advanced maternal age. Design: A historical cohort study of all women aged 45-47 years who gave birth to singletons at a tertiary medical centre between March 2011 and May 2018, at 24 weeks' gestation or later. Pregnancy outcomes were compared between donor oocyte (IVF-OD), IVF using autologous oocytes (IVF-A) and naturally conceived pregnancies. A multivariate logistic regression was used to evaluate the association between the mode of conception and gestational hypertensive disorders. Results: The final analysis included 159, 68 and 73 patients in the IVF-OD, IVF-A and natural conception groups, respectively. The rate of gestational hypertensive disorders was significantly higher among those who conceived by IVF compared with those who conceived naturally but did not differ between the two IVF groups (27.0% for IVF-OD, 19.1% for IVF-A, P = 0.204; 5.5% for natural conception, P < 0.001 and P = 0.013 compared with IVF-OD and IVF-A, respectively). The results remained similar in a multivariate logistic regression analysis. The rate of Caesarean deliveries was significantly higher in the IVF-OD and IVF-A groups compared with the natural conception group (83.6%, 70.6% and 37.0%, respectively, P < 0.001), but other pregnancy outcomes did not differ between the groups. Conclusions: IVF pregnancies in the late fifth decade of life were associated with significantly higher rates of gestational hypertensive disorders compared with naturally conceived pregnancies. No difference existed between the two IVF groups. These results may highlight the impact of IVF itself on gestational hypertensive disorders at very advanced maternal age.