Placenta accreta is associated with IVF pregnancies: a retrospective chart review

Objective To study the association between placenta accreta (PA) and in vitro fertilisation (IVF) pregnancies. Design Retrospective chart review. Setting Tertiary care centre in Jerusalem, Israel. Sample During January 2004-February 2009, 25 193 deliveries occurred in our hospital, including 752 (3%) deliveries of IVF pregnancies. Methods Placenta accreta was only diagnosed when there were histological findings from the placenta associated with the suitable clinical course. Demographic, obstetrical and fertility characteristics of these patients were retrieved from hospital files. Main outcome measure Rates of PA in pregnancies achieved with IVF versus rates of PA in spontaneous pregnancies. Results The rate of PA in the IVF group was 12/752 (16/1000) pregnancies, compared with 30/24 441 (1.2/1000) among spontaneous pregnancies (P < 0.0001; OR 13.2; 95% CI 6.7-25.8). Among the variables examined, parity, rate of caesarean delivery in the index pregnancy, and birthweight differed significantly between IVF and spontaneous pregnancies. Conclusions The odds of developing PA are significantly higher in IVF pregnancies than in spontaneous pregnancies. These differences may stem from differences in the endometrial environment, or from changes to the endometrium wrought by IVF treatment protocols.