Experience of the national cohort of pregnant women with HIV and their children in Spain: temporal trends in vertical transmission of HIV and associated infections

[Display omitted] The vertical transmission rate (VTR) of HIV has decreased to less than 2% in high-income countries, in spite of which perinatal infections continue to occur. We present data from the national cohort of pregnant women living with HIV and their children in Spain. The objectives were to describe the characteristics of this population, evaluate the VTR of HIV, the safety of antiretroviral therapy (ART) and the prevalence of coinfection. Multicentre prospective, observational and descriptive study with participation of 62 hospitals. The sample included pegnant women living with HIV whose children were born between January 2020 and December 2022. We collected prospective data on the characteristics of mothers and children using an online questionnaire (REDCap web application). The study included 414 mother-child dyads. Most mothers were immigrants (227/349; 65.1%). The main route of HIV infection was heterosexual transmission (160/402; 39.8%), followed by vertical transmission (44/402; 10.9%). The diagnosis was made before conception in 313/389 women (80.4%), 394/402 (98%) received ART during pregnancy and 356/402 (89.3%) had an undetectable viral load at the time of delivery. The delivery was vaginal in 230/388 children (59.3%). The proportion of preterm birth was 11.1%. The most frequent neonatal prophylaxis approach was monotherapy with zidovudine (358/414; 86.5%). There were 3 cases of vertical transmission of HIV (95% CI, 0%–1.54%). Only one newborn was breastfed. At present, most women living with HIV in Spain receive the diagnosis before conception, are of foreign ancestry and achieve good control of the infection. Although the VTR is very low in Spain, there are still infections that could be prevented with early diagnosis and treatment. La tasa de transmisión materno-infantil (TMI) del VIH ha disminuido a menos del 2% en países desarrollados, a pesar de lo cual siguen produciéndose infecciones. Se presentan los datos de la Cohorte Nacional Española de mujeres embarazadas que viven con VIH y sus hijos. Los objetivos fueron describir sus características, evaluar la TMI de VIH, la seguridad del tratamiento antirretroviral (TAR) y la prevalencia de coinfecciones. Estudio descriptivo, observacional, prospectivo y multicéntrico con participación de 62 hospitales. Se incluyeron las embarazadas cuyos hijos nacieron entre enero 2020 y diciembre 2022. Se recogieron prospectivamente características de las madres y niños en REDCap. Hubo 414 pares