Passive transplacental immunity against the respiratory syncytial virus (RSV) appears to mediate infant protection during the first 6 months of life (1). Observations of environmental exposure in pregnant women during an RSV epidemic could influence these children's susceptibility to infection by offering levels of antibodies that are transferred to the fetus. However, there is no prospective study in the population at risk such as children with congenital heart disease, as well as the effective levels of anti-RSV immunoglobulin G (IgG) as protective biomarkers for RSV infection after delivery (2)

Justification

The most serious evolution of the clinical disease of acute RSV bronchiolitis in children under 6 months of age is related to lower exposure of the pregnant woman to the RSV epidemic. With maternal immunization through natural exposure, it is logical to relate protection to children for severe RSV disease. However, it is not proven (3).

1. - Nandapalan N, Taylor CE, Greenwell J, et al. Seasonal variations in maternal serum and mammary immunity to RS virus. J Med Virol. 1986;20(1):79-87. doi:10.1002/jmv.1890200110
2. - Stensballe LG, Ravn H, Kristensen K, Meakins T, Aaby P, Simoes EA. Seasonal variation of maternally derived respiratory syncytial virus antibodies and association with infant hospitalizations for respiratory syncytial virus. J Pediatr. 2009;154(2):296-298. doi:10.1016/j.jpeds.2008.07.053
3. - Ramos-Fernández JM, et al. Does exposure of pregnant women to epidemic respiratory syncytial virus affect the severity of bronchiolitis? Enferm Infec Microbiol Clin. 2017. https://doi.org/10.1016/j.eimc.2018.07.002)

A prospective cohort study of mothers with a prenatal diagnosis of a fetus with congenital heart disease will be carried out. To whom titers will be measured. Anti-RSV IGG antibodies result from previous exposure.

According to the IGG titers in anti-RSV serum, 2 groups will be formed:

Protective Mothers (high IGG titers) Non-protective mothers (low IGG titers) The products will be followed up for 6 months after birth to correlate the maternal titers of Ac anti-RSV with the presence and severity of respiratory infection by RSV (Bronchiolitis) in this period.

Population and period

Pregnant women evaluated in the National Medical Center 20 de Noviembre, Pediatric Cardiology service for the prenatal diagnosis of congenital heart disease in their fetuses. Newborns with corroborated congenital heart disease with prenatal diagnosis.

Study inclusion period February 1, 2021, to October 30, 2021. Study follow-up period March 1 2021 to December 30 2021.

Sample type: Non-randomized, for convenience, sequential and with an estimated of 30 patients per group.

Inclusion Criteria:

1. Pregnant mothers in the third trimester of gestational age, with a child with congenital heart disease diagnosed by fetal echocardiogram
2. Approval of informed consent
3. Newborn of term or preterm, with corroborated congenital heart disease and presenting with a respiratory infection by RSV

Exclusion Criteria:

1. - Non-acceptance of informed consent
2. - Premature birth and need for neonatal intensive care for more than 4 weeks.
3. - Newborn with bronchopulmonary dysplasia

Elimination criteria

1.- Use of palivizumab

Pregnant women evaluated in the National Medical Center 20 de Noviembre, Pediatric Cardiology service for the prenatal diagnosis of congenital heart disease in their fetuses. Newborns with corroborated congenital heart disease with prenatal diagnosis.

Data are available upon direct request with the principal investigator through official and unofficial communication.

5 years