Sexual behavior and pregnancy outcome data for 392 HIV-infected women were analyzed. During the 6 months before study entry, 71.2% (279 of 392 women) were sexually active. In multivariate regression, women with baseline CD4+ > or = 200/microl were more likely than women with CD4+ < 200/microl to be sexually active (adjusted odds ratio [OR] = 1.75; 95% confidence interval [CI], 1.06-2.88; p = .03). Consistent condom use was reported with 58.4% (149 of 255) of steady male partners and 65.7% (23 of 35) of casual partners. Overall, 90.3% of 279 sexually active women were using contraception. Among women aged between 15 and 44 years (n = 320), the incidence of pregnancy in the year before HIV diagnosis was 27.5 per 100 person-years (PY) (95% CI, 22.1-33.9) compared with 8.3/100 PY (95% CI, 6.8-10.2) in the time since HIV diagnosis (p < .001). The incidence of therapeutic termination of pregnancies conceived in the 20 weeks before HIV diagnosis (10.6/100 PY) was more than triple that after diagnosis (3.1/100 PY; p = .001). After publication of results of zidovudine prophylaxis of mother-to-child transmission, pregnancy rates did not increase, but the incidence of therapeutic abortion dropped from 4.3/100 PY to 1.4/100 PY (p = .009). Knowledge of sexual behavior, including pregnancy frequency and outcome, can assist in tailoring counseling for HIV-infected women concerning sexual and reproductive health.