Comparison of perinatal health of children born from IVF in Finland in the early and late 1990s

BACKGROUND: The purpose of this study was to investigate whether perinatal health outcomes changed during the 1990s with the increasing use of IVF. METHODS: Data were from the Finnish Medical Birth Register for periods 1991-1993 and 1998-1999. Outcomes of IVF infants and other infants were compared, both overall and separately for singleton and multiple births, by adjusting for mothers' background variables by logistic regression. RESULTS: The IVF multiple birth rate, especially the number of triplets, declined from the first (1991-1993) to the second (1998-1999) time-period. The outcomes for IVF newborns improved, especially for multiple births. After adjusting for mothers' background variables, the odds ratios for preterm birth and low birthweight decreased among singletons from 2.2 [95% confidence interval (CI) 1.8-2.8] to 1.8 (CI 1.5-2.1) and from 2.4 (CI 1.9-3.1) to 1.7 (CI 1.4-2.1) respectively and more among multiples from 2.4 (CI 2.0-2.9) to 1.5 (CI 1.2-1.7) and from 1.9 (CI 1.6-2.3) to 1.1 (CI 1.0-1.3) respectively. Still, overall the outcomes for IVF infants remained poorer than those for other infants. A correlation was found between increased use of antenatal services and improved outcomes, but causality cannot be assumed. CONCLUSION: A trend of improved perinatal health of multiple IVF children was found, mainly due to a decrease in higher order multiple births.