Resum

Background: Children uninfected but exposed to HIV intra-utero (CHEU) are at higher risk of prematurity and low birth weight (LBW), factors associated with long-term growth impairment. Data is scarce regarding the effects of integrase inhibitor regimens during pregnancy in non-limited resource settings. Methods: Descriptive retrospective study of mother-child pairs from 62 Spanish hospitals in the National Cohort of Pregnant Women with HIV and their Children. All children born between January 2020 and December 2023 were included. Data on obstetric, virological, immunological, and antiretroviral treatment (ART) variables were analyzed for association with premature birth or LBWGA via univariate logistic regression models. Results : We included 502 pregnant women living with HIV and their 516 newborns. 32.6% were Caucasian and 44% had a first pregnancy. The median maternal age was 36 years [IQR 32-40]. At the last prenatal checkup, the median CD4 count was 631 cells/mm³ [IQR 435-835] and 88.4% of women were under viral suppression (<50 copies/mL). Regarding maternal ART, 59.7% were on integrase inhibitors (INSTIs), of which 17.9% (49/274) were on bictegravir. Prematurity incidence was 11.6%, with a median gestational age of 34.5 weeks [IQR 32-36]. An 8.7% of newborns were diagnosed with LBG, with a median weight of 2380 g [IQR 2250-2600]. Singleton pregnancies were associated with a 79% lower probability of prematurity (OR 0.21, 95%CI 0.06-0.66; p=0.007) and LBW (OR 0.21, 95% CI 0.06-0.71; p=0.012) than multiple pregnancies. Additionally, having at least one prenatal checkup each trimester was associated with a 69% lower likelihood of LBW (OR 0.31, 95% CI 0.14-0.68; p=0.003). We found no association between CD4 count or viral load at the last prenatal checkup and prematurity or LBWGA. Regarding ART, there were no significant differences in the clinical characteristics of mothers treated with INSTI-based regimens compared to those on protease inhibitors or non-nucleoside reverse transcriptase inhibitors. However, regimens including bictegravir were associated with a higher incidence of LBW (OR 2.5, 95%CI 1.08-5.84; p=0.03). Conclusions : Optimizing regimens during pregnancy is key for the prevention of poor outcomes, including impaired growth, in the expanding population of CHEU. Larger cohorts and long-term follow-ups are needed to identify optimal treatments, adjust for potential confounders, and inform future prevention and intervention strategies.