Characteristics and outcome of infants born to mothers with SARS-CoV-2 infection during the first three waves of COVID-19 pandemic in northern Iran: A prospective cross-sectional study.

Background: Despite the rapid increase in knowledge about coronavirus disease 2019 (COVID-19), there is limited data on vertical transmission, viral loads in mother-neonate pairs, and health outcomes. We aimed to describe the characteristics, viral loads, and short-and mid-term outcomes of neonates born to mothers with confirmed COVID-19 infection in northern Iran. Materials and methods: In a cross-sectional study, we prospectively collected and analyzed the clinical features, reverse transcription-polymerase chain reaction (RT-PCR) results, viral loads, and outcomes of 60 neonates delivered by 58 SARS-CoV-2 infected pregnant women in maternity hospitals of Mazandaran University of Medical Sciences (northern Iran) during first three waves of the pandemic from March 1 to December 31, 2020. We assessed neonates' short and mid-term outcomes up to 24 months after the pandemic. We also described the timing of mother-to-infant transmission based on the classification presented by the World Health Organization. Results: Of the 17767 deliveries, 58 mothers had confirmed and probable COVID-19 infection. Twenty (33.3%) neonates were positive for SARS-CoV-2, two of whom had possible in utero transmission. Twenty-five (41.2%) neonates were preterm, most of whom were born during the first and second waves in which mothers were critically ill. 19 (31.7%) patients needed resuscitation in the delivery room. 34 (56.7%) neonates were isolated in the neonatal intensive care unit. We observed a significant relationship between the maternal and neonatal viral load (correlation coefficient = 0.983, P = 0.00). No neonatal death was observed and all babies had a good outcome. Conclusions: The results showed that vertical transmission of SARS-CoV-2 is possible but rare. Regional factors and severity of mother's disease may influence the clinical course of neonates. With increasing experience, proper observance of health precautions, and rapid development of evidence-based response systems for regional and global disasters, the transmission rate of SARS-CoV-2 from mother to newborn is reduced.