Amniocentesis in HIV pregnant women: 16 years of experience.

The iatrogenic risk of HIV vertical transmission, calculated in initial epidemiologic studies, seemed to counterindicate invasive prenatal diagnosis (PND) procedures. The implementation of highly active antiretroviral therapy (HAART) represented a turning point in PND management, owing to a rapid and effective reduction of maternal viral load (VL). In the present study, we identified cases of vertical transmission in HIV-infected pregnant women who did amniocentesis in the second trimester of pregnancy (n = 27), from 1996 to 2011. We divided our sample into Group A--women under HAART when submitted to amniocentesis (n = 20) and Group B--women without antiretroviral therapy before amniocentesis (n = 7). We had 1 case of vertical transmission in Group B. Preconceptional or early first trimester HIV serology is essential to avoid performing an amniocentesis without antiretroviral therapy or viral suppression. When there is an indication for amniocentesis in an HIV-infected pregnant woman, it should be done if the patient is on HAART and, if possible, when VL is undetectable. Nowadays, with combined first trimester screening test to select pregnancies with high risk of aneuploidies, advanced maternal age is a less frequent indication to perform PND invasive procedures, representing an outstanding gain in prenatal diagnosis of this population.

Potential impact of viral load and genetic makeup of HIV type 1 on mother-to-child transmission: characterization of env-C2V3C3 and nef sequences.

HIV-1 mother-to-child transmission (MTCT) was evaluated in terms of the molecular characterization of the env and nef genomic regions and quantification of maternal RNA viral loads. Assignment of viral subtype was achieved by direct sequencing of PCR 1172 products amplified from proviral DNA in 45 HIV-1-nontransmitting mothers (NTM), along with 13 pairs of HIV-1-transmitting mothers (TM) and their infected children (C). Analysis of the env C2V3C3 and nef sequences revealed that subtypes G and B, and their genetic combinations (AG, BG), accounted for over 84.5% of all viruses identified. The genetic structure form envA-nefG was the most commonly observed, with a lower frequency in the NTM (13.3%) compared to the TM (23.1%) group. A greater number of genetic forms was observed among NTM, namely the presence of sequences assigned to subtypes D and F, as well as the intergenetic A/J, and C/U, recombinant forms, along with a mosaic provirus with a complex putative envA-nefEGE genetic structure. No significant differences were found when RNA viral loads were evaluated as a function of the viral subtypes. Nevertheless, a relatively high quantification of HIV-1 RNA was obtained in the NTM group, emphasizing the importance of the compliance and effectiveness of therapeutic schemes to control viral replication and reduce the risk of HIV vertical transmission. V3 sequences displaying features associated with the R5 phenotype dominated in both groups. Both C2V3C3 and Nef's functional domains were conserved during HIV-1 vertical transmission.