CASE-CONTROL STUDY OF THE RISK-FACTORS FOR ECLAMPSIA

A case-control study was conducted to investigate risk factors for ecl ampsia. A total of 66 cases of eclampsia were ascertained from deliver ies between 1977 and 1992 at two hospitals in Houston, Texas, based on the criteria defined by the American College of Obstetrics and Gyneco logy. Cases were matched to nonpreeclamptic controls on a 4:1 ratio on the basis of hospital and month of delivery, The ratio of eclampsia c ases to number of deliveries over the study period was 0.63 per 1,000. In a logistic regression model, risk factors for eclampsia included 1 ) two or fewer prenatal care visits (odds ratio (OR) = 6.10, 95% confi dence interval (Cl) 2.26-16.41), 2) urinary tract infection (OR = 4.23 , 95% Cl 1.27-14.06), 3) primigravidity (OR = 2.87, 95% Cl 0.97-8.44), 4) obesity (OR = 2.49, 95% Cl 0.78-7.96), 5) black ethnicity (OR = 2. 25, 95% Cl 0.88-5.78), 6) history of diabetes (OR = 2.07, 95% Cl 0.45- 9.62), and 7) age less than or equal to 20 years (OR = 1.55, 95% Cl 0. 47-5.10). Nulliparity was not shown to be a risk factor for eclampsia when controlled for primigravidity, and neither were previous history of abortion or previous history of pregnancy-induced hypertension, Thu s, prior pregnancy itself, independent of outcome and preeclamptic/ecl amptic complications, appears to be the protective factor against ecla mpsia in a subsequent pregnancy.