Maternal and child outcome after in vitro fertilization--a review of 25 years of population-based data from Sweden

Objective: To summarize data on deliveries after in vitro fertilization (IVF) performed in Sweden up to 2006.

Design: Cohort study of women and children, conceived after IVF, with comparisons of deliveries after IVF before and after 1 April 2001.

Setting: Study based on Swedish health registers.

Population: Births registered in the Swedish Medical Birth Register with information on IVF from all IVF clinics in Sweden.

Methods: Results from the second study period are summarized, and outcomes between the two periods are compared. Long-term follow-up is based on data from both periods.

Main outcome measures: Maternal and perinatal outcomes, long-term sequels.

Results: Some maternal pregnancy complications decreased in rate, notably pre-eclampsia and premature rupture of membranes. The rate of multiple births and preterm births decreased dramatically, with a better neonatal outcome, including reduced neonatal mortality. No difference in outcome existed between IVF and intracytoplasmic sperm injection or between the use of fresh and cryopreserved embryos, but children born after blastocyst transfer had a slightly higher risk for preterm birth and congenital malformations than children born after cleavage stage transfer. An increased risk for cerebral palsy, possibly for attention deficit and hyperactivity disorder, for impaired visual acuity and for childhood cancer was noted, but these outcomes were rare also after IVF. An increased risk for asthma was demonstrated. No effect on maternal cancer risk was seen.

Conclusion: A marked decrease in multiple births was the main reason for better pregnancy and neonatal outcome and may also have a beneficial effect on long-term results, notably cerebral palsy.