Higher rate of early-onset preeclampsia in pregnancies following oocyte donation according to increasing maternal age

Objective: To assess the influence of maternal age on the incidence of early-onset preeclampsia requiring delivery before 34 weeks of gestation in pregnancies obtained after oocyte donation. Methods: We carried out a prospective cohort analysis of 431 single and twin pregnancies, admitted to 3 Tertiary Referral Hospital in Northern Italy between 2008 and 2017. The rate of early-onset PE was calculated and stratified according to maternal age (from 30 to 49 years). A reference population of 11,197 single pregnancies collected prospectively at the first trimester of pregnancy in the same geographic area of Italy and in same hospitals was used to calculate the expected incidence of early-onset PE. Results: In women who delivered after 24 weeks of gestation, the rate of early-onset PE was much higher in oocyte-donation pregnancies, reaching 6.7% (29/431), than the expected rate of 0.5% of the cohort of reference. The mean early PE rate was 4.1% (10/242) in singletons and 10.1% (19/189) in twin pregnancies. According to maternal age, the rate of early PE was 1.16% and 3.12% at 30 years, and 4.98% and 13.14% at 49 years in single and twin pregnancies obtained after oocyte donation, respectively. Conclusion: Pregnancies obtained after oocyte donation delivering after 24 weeks had a higher risk of early-onset PE requiring delivery before 34 weeks of gestation, than the general population. The risk is directly correlated with the increase of maternal age and is also higher in twin pregnancies.