Effect of the interval between pregnancies on perinatal outcomes among white and black women.

Abstract

We evaluated interpregnancy interval in relation to adverse perinatal outcomes and whether the relationship differed by race. We analyzed the vital statistics data for multiparous white and black women in Michigan who delivered a singleton live birth during the period 1993 through 1998, using stratified and logistic regression techniques. Among women of both races, the risk for delivering low birth weight, premature, and small-for-gestational-age birth was lowest if the interpregnancy interval was 18 to 23 months. In comparison, among white women, the odds ratios for the 3 outcomes were 1.5, 1.3, and 1.3, respectively, if the interval was <6 months, and 1.9, 1.4, and 1.7, respectively, if the interval was > or =120 months, controlling for other factors. Similarly, among black women, the odds ratios were 1.5, 1.2, and 1.3, respectively, if the interval was <6 months, and 1.6, 1.3, and 1.4, respectively, if the interval was > or =120 months. An interpregnancy interval of 18 to 23 months is associated with the lowest risk for adverse perinatal outcomes among both white and black women.