The effects of in vitro fertilization on subsequent pregnancy outcome

Objective: The purpose of this study was to look at the effects of assisted reproductive technology on subsequent pregnancy outcome variables.Methods: This retrospective study was performed using the Regional Perinatal Data System, a population-based birth registry. The data system is used by all 23 hospitals in the 14-county region of Central New York. 42,656 births were analyzed from January 1, 1995 through December 31, 1996. The associations between in vitro fertilization and premature rupture of membranes (PROM), preterm delivery (PTD), age, gravidity, parity, and race were evaluated using chi(2) and Fisher's two-tailed Exact analyses. Odds ratios represent the magnitude of the association.Results:Women undergoing in vitro fertilization were significantly more likely to experience PTD and PROM. They were significantly more likely to be nulliparous, primigravidas, or over the age of 34.Conclusions: This analysis shows a strong association between women who have undergone in vitro fertilization and adverse pregnancy outcomes including PROM and preterm delivery. This study suggests a need for intensified obstetric care and the assignment of high risk pregnancy status to those women who have undergone in vitro fertilization. This association has not been previously reported and underscores the need for a comprehensive data system to analyze adverse events within a region and develop strategies for prevention.