Vertical transmission of HIV from 2007 to 2018 in a reference university hospital in Rio de Janeiro

The aim of the study was to assess the factors associated with mother-to-child transmission (MTCT) of HIV. The study design is a retrospective cohort. The population consisted of 323 HIV-positive mothers and their newborns, attended at the Perinatal Nucleus/HUPE-UERJ, municipality of Rio de Janeiro, in the period of 2007-2018. The average age of mothers was 27 years (14-44), with 12.7% (41) of adolescents. The majority (66.8%) knew they were infected during pregnancy: 39.4% in the current pregnancy and 27.4% in a previous pregnancy. The incidence of MTCT was 2.7% in 2007-2009, 1% in 2010-2015 and 0 in 2016-2018. The viral load in the 3rd trimester of pregnancy was > 1.000 copies/mL or unknown in all mothers with positive newborns and in 19% (42/221) of mothers with negative newborns (p=0.003). The duration of antiretroviral use was > 4 weeks in 92.3% (264/286) of mothers with HIV-negative newborns and in 2 in the HIV-positive group (p=0.004). One of the 4 infected newborns and 2 of the negative ones did not use oral zidovudine (p=0.04). There was no association between amniorrhexis and MTCT (p=0.99), with the Apgar score in the 5th minute of life (p=0.96), with marital status (p=0.54), ethnicity (p=0.65), adolescence (p=0.42), mode of delivery (p=0.99), beginning of prenatal care (p=0.44) or with maternal comorbidities (p=0.48). The conclusion of the study points out that the main factors associated with MTCT are the elevated maternal viral load in the 3rd trimester, the time of use of ART and the non-administration of zidovudine for the newborns.