Adverse obstetric outcomes in pregnancies resulting from oocyte donation: a retrospective cohort case study in Sweden

BACKGROUND: Oocyte donation has been associated to gestational diabetes, hypertensive disorders, placental abnormalities, preterm delivery and increased rate of caesarean delivery while simultaneously being characterized by high rates of primiparity, advanced maternal age and multiple gestation constituting the individual risk of mode of conception difficult to assess. This study aims to explore obstetrical outcomes among relatively young women with optimal health status conceiving singletons with donated versus autologous oocytes (via IVF and spontaneously). METHODS: National retrospective cohort case study involving 76 women conceiving with donated oocytes, 150 nulliparous women without infertility conceiving spontaneously and 63 women conceiving after non-donor IVF. Data on obstetric outcomes were retrieved from the National Birth Medical Register and the medical records of oocyte recipients from the treating University Hospitals of Sweden. Demographic and logistic regression analysis were performed to examine the association of mode of conception and obstetric outcomes. RESULTS: Women conceiving with donated oocytes (OD) had a higher risk of hypertensive disorders [adjusted Odds Ratio (aOR) 2.84, 95 % CI (1.04–7.81)], oligohydramnios [aOR 12.74, 95 % CI (1.24–130.49)], postpartum hemorrhage [aOR 7.11, 95 % CI (2.02–24.97)] and retained placenta [aOR 6.71, 95 % CI (1.58–28.40)] when compared to women who conceived spontaneously, after adjusting for relevant covariates. Similar trends, though not statistically significant, were noted when comparing OD pregnant women to women who had undergone non-donor IVF. Caesarean delivery [aOR 2.95, 95 % CI (1.52–5.71); aOR 5.20, 95 % CI (2.21–12.22)] and induction of labor [aOR 3.00, 95 % CI (1.39–6.44); aOR 2.80, 95 % CI (1.10–7.08)] occurred more frequently in the OD group, compared to the group conceiving spontaneously and through IVF respectively. No differences in gestational length were noted between the groups. With regard to the indication of OD treatment, higher intervention was observed in women with diminished ovarian reserve but the risk for hypertensive disorders did not differ after adjustment. CONCLUSION: The selection process of recipients for medically indicated oocyte donation treatment in Sweden seems to be effective in excluding women with severe comorbidities. Nevertheless, oocyte recipients-despite being relatively young and of optimal health status- need careful counseling preconceptionally and closer monitoring prenatally for the development of hypertensive disorders.