Strategies for Prevention of Mother-to-Child Transmission Adopted in the "Real-World" Setting: Data From the Italian Register for HIV-1 Infection in Children

Background: Strategies for prevention of HIV-1 mother-to-child transmission (PMTCT) have been continuously optimized. However, cases of vertical transmission continue to occur in high-income countries. Objectives: To investigate changes in PMTCT strategies adopted by Italian clinicians over time and to evaluate risk factors for transmission. Methods: Data from mother-child pairs prospectively collected by the Italian Register, born in Italy in 1996-2016, were analyzed. Risk factors for MTCT were explored by logistic regression analyses. Results: Six thousand five hundred three children (348 infections) were included. In our cohort, the proportion of children born to foreign mothers increased from 18.3% (563/3078) in 1996%-2003% to 66.2% (559/857) in 2011-2016 (P < 0.0001). Combination neonatal prophylaxis use significantly (P < 0.0001) increased over time, reaching 6.3% (56/857) after 2010, and it was largely (4.2%) adopted in early preterm infants. The proportion of vaginal deliveries in women with undetectable viral load (VL) increased over time and was 9.9% (85/857) in 2011-2016; no infection occurred among them. In children followed up since birth MTCT, rate was 3.5% (96/2783) in 1996-2003; 1.4% (36/2480) in 2004-2010; and 1.1% (9/835) in 2011-2016. At a multivariate analysis, factors associated with MTCT were vaginal delivery with detectable or missing VL or nonelective caesarean delivery, prematurity, breastfeeding, lack of maternal or neonatal antiretroviral therapy, detectable maternal VL, and age at first observation. Previously described increased risk of offspring of immigrant women was not confirmed. Conclusions: Risk of MTCT in Italy is ongoing, even in recent years, underling the need for implementation of the current screening program in pregnancy. Large combination neonatal prophylaxis use in preterm infants was observed, even if data on safety and efficacy in prematures are poor.