[Hypertension associated with pregnancy. Epidemiologic study of 311 consecutive cases].
The epidemiologic aspects of 311 consecutive cases of hypertension associated with pregnancy seen in the Department of Obstetrics and Gynecology, Hospital de Santa Maria/University of Lisbon Medical School between January 1st 1988 and December 31st 1992, are reviewed. Seventeen cases were multifetal pregnancies. Using the criteria proposed by the American College of Obstetricians and Gynecologists the cases were classified as follows: Mild preeclampsia, 64 cases (7 in twins); severe preeclampsia 50 cases (5 in twins); chronic hypertensive disease, 81 (1 in twins); chronic hypertension with superimposed preeclampsia, 16 (all singleton pregnancies); transient hypertension of pregnancy, 84 (4 in twins); unclassified hypertension, 16 cases of singleton pregnancies. No maternal deaths occurred. The most frequent maternal complications (eclampsia, HELLP syndrome, abruptio placentae and acute renal failure) were seen in preeclampsia (mild and severe forms). Only 2 significant maternal complications were observed in the cases of superimposed preeclampsia on chronic hypertensive disease. In the other groups maternal complications were seldom seen. Excepting in transient hypertension, perinatal morbidity and mortality were frequent in all groups, specially in severe preeclampsia and superimposed preeclampsia, when the delivery occurred before 34 weeks; after that time of pregnancy there were no neonatal deaths in any of the groups and intrauterine growth retardation and fetal distress were the most common fetal complications in all groups. In the whole, uncomplicated chronic hypertension and transient hypertension of pregnancy were the clinical situations in which maternal and perinatal complications were milder and less frequent. No perinatal problems were found in the group of unclassified hypertension.