Nausea and vomiting during teenage pregnancy: effects on birth weight.

Early pregnancy nausea and vomiting (NVP) has been reported to be a favorable risk factor for pregnancy outcome. We studied nausea and vomiting in 239 randomly selected teens from a geographic-based cohort of nearly 2800 pregnant adolescents from Camden County, New Jersey. Early (first trimester) NVP was reported by 20.9%, and an additional 17.6% reported that their NVP persisted into the second or third trimester (late NVP). After adjusting for confounding factors (length of gestation, maternal age, ethnicity, prepregnant body mass index, weight gain, and smoking), we found that early NVP alone did not significantly affect birth weight. Late NVP, however, was associated with a significant decrement in birth weight (-256.5 +/- 108.0 g, p less than 0.05). Further, the effect of late NVP was greater when maternal weight gain was inadequate. Teenagers with continued NVP are more likely to be nutritionally stressed during the course of their pregnancy.