OBJECTIVE: The current literature emphasizes increased risk of adverse outcomes in the presence of proteinuria and hypertension. The objective of this study was to compare the frequency of adverse fetal outcomes in women who developed hypertensive disorders with or without proteinuria. STUDY DESIGN: The study design was a secondary analysis of data from women who had preeclampsia in a previous pregnancy (n = 598) who were enrolled in a multicenter trial of aspirin for the prevention of preeclampsia. The women had no history of chronic hypertension or renal disease and were normotensive at study inclusion. The maternal and perinatal outcome variables assessed were preterm delivery at <37 and <35 weeks of gestation, rate of small-for-gestational-age infants, and abruptio placenta. Data were analyzed by using the chi-square test, and women who remained normotensive or who had mild gestational hypertension were considered as a single group because they had similar outcomes. RESULTS: As compared to mild preeclampsia, women who developed severe gestational hypertension (without proteinuria) had higher rates of both preterm delivery at <37 weeks of gestation and small-for-gestational-age infants. In addition, when compared to women with mild preeclampsia, for women with severe gestational hypertension, gestational age and birth weight were significantly lower at delivery (P <. 003 for both age and birth weight). Moreover, women who developed severe gestational hypertension had higher rates of preterm delivery at <37 weeks of gestation (54.2% vs 17.8%, P =. 001) and at <35 weeks of gestation (25.0% vs 8.4%, P =. 0161), and delivery of small-for-gestational-age infants (20.8% vs 6.5%, P =. 024) when compared to women who remained normotensive or those who developed mild gestational hypertension. There were no statistically significant differences in perinatal outcomes between the normotensive/mild gestational hypertension and the mild preeclampsia groups. Overall, women who had severe gestational hypertension had increased rates of preterm delivery and delivery of small-for-gestational-age infants than women with mild gestational hypertension or mild preeclampsia. In the presence of severe hypertension, proteinuria did not increase the rates of preterm delivery or delivery of small-for-gestational-age infants. CONCLUSIONS: In women who have gestational hypertension or preeclampsia, increased rates of preterm delivery and delivery of small-for-gestational-age infants are present only in those with severe hypertension. In these women, the presence of proteinuria does not influence perinatal outcome. © 2002 by Mosby, Inc.