Early gestational bleeding and pregnancy outcome: a multivariable analysis.

The effect of early vaginal bleeding on pregnancy outcome was assessed for 16 305 singleton stillborn and liveborn deliveries at three obstetric units in Jerusalem, Israel during 1975-1976. A total of 2385 women (14.6%) reported gestational bleeding before the seventh month of pregnancy. Of these, 2166 reported light bleeding (spotting), 191 heavy bleeding, and 28 both light and heavy bleeding. Logistic regression models revealed an unexpected interaction among light bleeding, hormone usage, and pregnancy outcome in that the risks of a low birth weight, pre-term and small-for-dates term delivery were significantly increased only for those women who had light bleeding and who had not used therapeutic hormones. Heavy vaginal bleeding, in contrast, was associated with an excess risk of these perinatal complications regardless of hormone usage. There was also a suggestion that certain subgroups of women with vaginal bleeding might be at an increased risk of delivering an offspring with congenital malformations.