Maternal and neonatal outcomes of pregnancies obtained by homologous versus heterologous assisted reproduction technique: a single centre retrospective observational study

BACKGROUND: Assisted Reproduction Technologies (ART) have acquired a growing role in the treatment of fertility worldwide. Pregnancies obtained with ART generally has positive outcomes, but adverse effects on the health of the mother and the child have been reported. Comparisons between different techniques show a different influence on the incidence of complications, with oocyte donation being associated with overall higher risks for maternal and foetal health. METHODS: We carried out a single-centre retrospective study on a cohort of women who had obtained pregnancy through ART. The population was divided into heterologous ART and homologous ART, and maternal and foetal outcomes were compared. Maternal outcomes were gestational hypertension, preeclampsia, intrahepatic cholestasis, intrauterine foetal death, preterm premature rupture of membranes, preterm delivery, use of prophylaxis during the first trimester (low molecular weight heparin, cardioaspirin, cortisone), mode of delivery. Neonatal outcomes were low birth weight and small for gestational age. RESULTS: Of the selected 140 patients, 56 belonged to the heterologous ART group (40.0%), and 84 to the homologous ART group (60.0%). The two groups presented with a significant difference in mean age, 39.7 in the group of pregnancies achieved with homologous ART versus 40.7 in the group of pregnancies achieved through heterologous ART. Preterm delivery occurred in 2.4% of autologous ART pregnancies compared to 14.5% of heterologous ART pregnancies (p<0.05). When adjusted for parity and age, heterologous ART was not independently related to preterm birth (OR 2.980; 95% CI 0.533 – 16.679). Elective caesarean section was more common in the group of heterologous ART compared to that of homologous ART (50.0% vs 30.9%, p<0.05). When adjusted for parity and age, however, homologous ART was not independently related to an increase in caesarean sections (OR 0.962; 95%CI 0.424 – 2.184). CONCLUSIONS: Although a large literature confirms the association between oocyte donation (heterologous ART) and an increase rate of maternal and foetal adverse outcomes if compared to homologous ART, our study did not yield any statistically significant differences between the incidence of adverse outcomes in the two groups. Preterm birth and the rate of elective caesarean sections seemed higher in the heterologous ART group. Further studies should be performed in order to better explore the correlation between heterologous ART and maternal and foetal complications, the reasons for such increased risk and how to prevent negative outcomes.