Maternal SARS-CoV-2 infection: What to expect in newborns

ABSTRACT

Background: The COVID-19 pandemic has changed the paradigm when it comes to infection control. However, there are still many doubts about pregnancy and the perinatal period in this context, even though many studies suggest the benignity of infection in this phase. The present study took place in a Level II Hospital with differentiated perinatal care and describes the newborns whose mothers were infected with COVID-19 during pregnancy. We aim to understand the mother-newborn pattern of transmission and clinical, analytical and serologic follow-up. Methods: Prospective observational study from 1/4/2020 to 31/5/2021, using the clinical files of every SARS-COV-2 PCR-positive mother and their newborns. Among others, we evaluated the state of infection of the newborn at 12 and 48h and after 14 days with SARS-Cov-2 PCR tests. In the first three months, serologic and clinical evaluation were performed. Results: Of the 1684 live births, 60 (3,6%) mothers were infected with SARS-COV-2 during pregnancy, 43% of which were diagnosed in the screening performed during/before labour. The median value of gestational age was 39 weeks, and the average weight was 3171g. 81,7% of the newborns remained with their mother in the hospital ward, and 85% were breastfed. 7 newborns (11,7%) needed NICU, one of which was born at 32 weeks because the mother needed ICU support due to COVID-19. Of the 26 newborns whose mothers were positive in labour, 15 were tested for SARS-Cov-2 PCR in the first 12 h, and 21 within 48h all of them were negative.16 were tested after 14 days. Only one of them (6,2%) tested positive but remained asymptomatic. Serologic anti-spike and anti-nucleocapsid analyses were performed in 32 babies 10 of them (31.3%) showed positive antibodies. In these cases, 80% of the mothers were positive in the 3rd trimester and 20% in the 2nd trimester. The clinical follow-up showed a positive outcome in all of them. Conclusions: This study supports others that show the benignity of perinatal SARS-COV-2 infection. There were no more significant rates of prematurity or NICU need. None of the newborns tested positive in SARS-Cov-2 PCR tests in the first 48h, supporting the rarity of the vertical infection, and only one has been affected by horizontal transmission.