Obstetric outcome of singleton pregnancies after IVF: a matched control study in four Dutch university hospitals

In singleton pregnancies after IVF a high rate of preterm deliveries and an increased rate of small-for-gestational age (SGA) children in comparison t o the general parturient population have been reported. However, due to dif ferences between IVF mothers and their peers who conceived naturally, caref ul selection of the control group is necessary to assess whether IVF pregna ncies really carry increased risks of adverse outcome. In our study 307 IVF pregnancies were compared with 307 control pregnancies after elaborate mat ching for an extensive number of maternal characteristics, as well as for t he hospital that provided the obstetric care. Four Dutch university hospita ls contributed to the study. In cases with spontaneous onset of labour, ges tational age at delivery was 3 days shorter in the IVF group (275 versus 27 8 days, P = 0.05), The proportion of SGA was higher in the IVF group (16.2 versus 7.9%, P < 0.001), The combination of these two results denotes a dis tinct difference between IVF and control pregnancies. Placental weight was comparable in both groups.