Diagnosis of HIV infection in pregnancy: data from a national cohort of pregnant women with HIV in Italy

We analysed the characteristics of the pregnancies with a previously undetected HIV infection in a national observational study of pregnant women with HIV in Italy. In a total of 443 pregnancies with available date of HIV diagnosis, 118 were characterized by a previously undetected HIV infection (26(.)6 %, 95 % CI 22(.)5-30(.)8). The following factors were independently associated with this occurrence in a multivariate analysis (adjusted odds ratios; 95 % CIs): foreign nationality (5(.)1, 2(.)8-9(.)3); no pre-conception counselling (35(.)9, 4(.)8-266(.)1); first pregnancy (2(.)1, 1(.)2-4(.)0); asymptomatic status (6(.)8, 1(.)5-30(.)6). Women with previously undetected infection started antiretroviral treatment significantly later during pregnancy (P < 0(.)001). Missed diagnosis was responsible for one case of transmission. A high rate of previously undetected HIV infection was observed. This suggests a good HIV detection during pregnancy, but also the need to reinforce HIV testing strategies among women of childbearing age. We identified some determinants which may be considered for intervention measures.