DETERMINANTS OF RISK OF SPONTANEOUS-ABORTIONS IN THE FIRST-TRIMESTER OF PREGNANCY

Several factors, such as socioeconomic status, obstetrical and menstru al history, and contraceptive methods, have been associated with risk of spontaneous abortion. We conducted a hospital case-control study to analyze risk factors for spontaneous abortion during the first trimes ter. Cases were 782 women admitted for spontaneous abortion. Controls included 1,543 women who gave birth at term in the same hospitals. Adj usted odds ratios (ORs) for spontaneous abortion were 0.9 and 0.6, res pectively, for women reporting 7-11 and greater than or equal to 12 ye ars of schooling, compared with women reporting <7 years of education. A history of pelvic inflammatory disease increased the odds ratio fiv efold [OR = 5.1; 95% confidence interval (CI) = 1.0-26.2]. The OR for spontaneous abortion was 1.7 (95% CI = 1.4-2.1) in women reporting pre vious spontaneous abortions.