Maternal and fetal outcomes in oocyte donation pregnancies

BACKGROUND: Since the first successful use of donated oocytes in 1984, the number of oocyte donation cycles in Europe and the USA has dramatically increased. Consequently, there has been increasing interest in the impact of oocyte donation on maternal and fetal outcomes. OBJECTIVE AND RATIONALE: The aim of this review was to summarize the literature regarding maternal and fetal outcomes from pregnancies conceived through oocyte donation. SEARCH METHODS: Identification of relevant publications was through research within the Embase Medline and PubMed databases, the Google-indexed scientific literature and periodic specialized magazines from the on-line Library Service of the University of Milan. OUTCOMES: Oocyte donation seems to be independently associated with a higher rate of pregnancy-induced hypertension and pre-eclampsia. An explanatory hypothesis is that an immunological maladaptation causes placenta-mediated disorders in oocyte donation pregnancies. The risks are even higher in twin pregnancies. Oocyte donation also seems to be associated with lower fetal birthweight. However, after adjusting for obstetric complications, most studies report less pronounced differences in birthweight or no dissimilarities. The incidence of cesarean section is increased without clear clinical indications. WIDER IMPLICATIONS: Oocyte donation pregnancies are associated with a higher rate of placental disorders of pregnancy, such as gestational hypertension and pre-eclampsia. The risk of poorer neonatal outcomes is increased in oocyte donation pregnancies compared to other in-vitro fertilization pregnancies. Poorer outcomes have been demonstrated especially for twin pregnancies and in association with previous chronic pathologies or the development of obstetrics complications.