Screening for human immunodeficiency virus infection during pregnancy.

Due to the increased risk of human immunodeficiency virus (HIV) infection during the childbearing years, voluntary screening during the prenatal period has been suggested. To study the impact of such a program in our population of pregnant women, we offered HIV testing to all prenatal patients with informed consent, beginning January 1, 1992. After 18 months (July 1993), HIV testing was offered as a component of our prenatal laboratory panel, using informed refusal. During the first screening period, there were 20 seropositive women among the 14,143 patients (1.4/1000), with 74 refusing testing. During the next 36 months (July 1993 to June 1996), 91 seropositive gravidas were identified among 31,496 parturients (2.9/1000), with only 17 refusing assessment. Free treatment with zidovudine (AZT) for both mother and baby, sponsored by the Mississippi state health department, began in January 1994. The perinatal transmission rate was 33% before AZT treatment, during our period of assessment, and was reduced to 10% during the next 30 months. Based on our data, it appears that a program of universal voluntary screening for HIV infection using informed refusal and free AZT for patients at risk for perinatal transmission results in almost 100% testing and a reduction in vertical transmission.