Obstetric outcome of in vitro maturation treatment and risk of congenital malformations

Abstract

In vitro maturation (IVM) does not require ovarian stimulation (OS), and sex steroid levels remain at physiological range during the treatment cycle. This could be more important than initially thought, because recent findings suggest an association between OS and preterm birth and small-for-gestational-age babies. Even singletons from conventional OS–IVF cycles are found to be at higher risk of preterm birth and weigh less than spontaneously conceived infants. Currently available data on IVM infants show that they are not more likely to be delivered preterm or not more likely to be underweight than infants conceived spontaneously or by OS–IVF. To the contrary, they appear to weigh heavier than IVF infants. The risk of major birth defects does not seem to increase in IVM infants as compared to conventional OS–IVF infants or the general population. Beyond the well-known benefit of decreasing the risk of ovarian hyperstimulation syndrome and avoiding estrogen exposure in patients with hormone sensitive tumors, the above-mentioned findings can be corroborated in future studies; IVM or natural cycle IVF/M may also prove advantageous by avoiding obstetric complications associated with abnormal placentation observed in OS–IVF pregnancies.