P-751 Development of hypertensive complications in oocyte donation pregnancy: a systematic review and individual participant data meta-analysis (DONOR IPD)
Authors: Van Bentem K , Van der Hoorn M  L , Van Lith J , Le Cessie S , Lashley L 
Published: July 2024

Abstract

Study question
Is the risk for hypertensive complications, including pregnancy-induced hypertension and preeclampsia, increased in oocyte donation pregnancy compared to autologous oocyte pregnancies?

Summary answer
We found an approximate 2.5-fold increased risk for hypertensive complications in oocyte donation pregnancy compared to autologous oocyte pregnancy using individual participant data meta-analysis approaches.

What is known already
Oocyte donation (OD) is an established assisted reproductive technique involving an oocyte donor and recipient. Due to the expansion of indications and emerging trends, the number of OD treatments is rising. Previous meta-analyses highlight increased risks of hypertensive complications compared to naturally conceived (NC) and IVF/ICSI pregnancies, including pregnancy induced hypertension (PIH) and preeclampsia (PE). However, limitations exist due to study quality, lack of correction for confounders, and heterogeneity.

Study design, size, duration
We conducted the DONation of Oocytes in Reproduction individual participant data (DONOR IPD) meta-analysis to determine the risk for the development of hypertensive complications in OD pregnancy, in comparison to autologous oocyte pregnancy. The DONOR IPD meta-analysis aims to address confounders, enhance statistical power, and provide robust evidence.

Participants/materials, setting, methods
A literature search was conducted using PubMed, EMBASE and Cochrane up to March 2023. We included observational studies that compared OD pregnancy beyond 20 weeks of gestation with autologous pregnancy, reporting on hypertensive pregnancy complications. Authors of eligible articles asked to share IPD. The DONOR IPD meta-analysis was executed using both a one- and two-stage approach, adjusted for confounders maternal age, parity and multiple gestation. Furthermore, sensitivity, meta-regression and subgroup analyses were performed.

Main results and the role of chance
IPD was sought for 58 cohorts, and eventually provided from sixteen cohorts with data of 2,747 OD, 4,699 autologous IVF/ICSI, and 33,323 NC pregnancies in total. The one- and two-stage approach comparing OD to autologous pregnancy resulted in adjusted ORs of respectively 2.62 (95% CI 2.22-3.10) and 2.65 (95% CI 2.08-3.39) for hypertensive complications in total, 2.15 (95% CI 1.73-2.68) and 1.49 (95% CI 0.80-2.80) for PIH, and 2.28 (95% CI 1.88-2.78) and 2.39 (95% CI 1.94-2.94) for PE. When the autologous group was split in NC and IVF/ICSI pregnancies, the higher risks in OD pregnancy for hypertensive complications, including PIH and PE, remained. However, compared to autologous pregnancies no significant increase in the risk for HELLP syndrome was observed in OD pregnancy.

Limitations, reasons for caution
The use of IPD still encounters certain limitations, such as IPD availability bias, and the dependency of methodological quality and heterogeneity of primary studies. To address these issues, we conducted additional sensitivity, meta-regression, and subgroup analyses.

Wider implications of the findings
Currently, none of the worldwide used guidelines indicate OD as a risk factor for hypertensive complications. As the DONOR IPD meta-analysis results in the best evidence based statement for international guidelines in obstetrics untill now, alertness of health care professionals must be increased towards the risk profile of these pregnancies.

Trial registration number
Financial support from the Leiden University Medical Center (the Netherlands) for an MD/PhD grant for K. van Bentem.