Routine prenatal screening for HIV in a low-prevalence setting

The objectives of this study were to assess the effect of British Columbia's June 1994 guidelines for prenatal HIV screening on the rate of maternal-fetal HIV transmission and to estimate the cost-effectiveness of such screening. The authors conducted a retrospective review of pregnancy and delivery statistics, HIV screening practices, laboratory testing volume, prenatal and labour management decisions of HIV-positive women, maternal-fetal transmission rates and associated costs. Over 1995 and 1996, 135,681 women were pregnant and 92,645 carried to term. The rate of HIV testing increased from 55% to 76% of pregnancies on chart review at one hospital between November 1995 and November 1996. On the basis of seroprevalence studies, an estimated 50.2 pregnancies and 34.3 (95% confidence interval 17.6 to 51.0) live births to HIV-positive women were expected. Of 42 identified mother-infant pairs with an estimated date of delivery during 1995 or 1996, 25 were known only through screening. Of these 25 cases, there were 10 terminations, 1 spontaneous abortion and 14 cases in which the woman elected to carry the pregnancy to term with antiretroviral therapy. There was one stillbirth. One instance of maternal-fetal HIV transmission occurred among the 13 live births. The net savings attributable to prevented infections among babies carried to term were $165,586, with a saving per prevented case of $75,266. A routine offer of pregnancy screening for HIV in a low-prevalence setting reduces the rate of maternal-fetal HIV transmission and may rival other widely accepted health care expenditures in terms of cost-effectiveness.