To describe how SARS-CoV-2 infection at the time of delivery affected maternal and neonatal outcomes across four major waves of the COVID-19 pandemic in Italy. This is a large, prospective, nationwide cohort study collecting maternal and neonatal data in case of maternal peripartum SARS-CoV-2 infection between February 2020 and March 2022. Data were stratified across the four observed pandemic waves. Among 5201 COVID-19-positive mothers, the risk of being symptomatic at delivery was significantly higher in the first and third waves (20.8-20.8%) than in the second and fourth (13.2-12.2%). Among their 5284 neonates, the risk of prematurity (gestational age <37 weeks) was significantly higher in the first and third waves (15.6-12.5%). The risk of intrauterine transmission was always very low, while the risk of postnatal transmission during rooming-in was higher and peaked at 4.5% during the fourth wave. A total of 80% of positive neonates were asymptomatic. The risk of adverse maternal and neonatal outcomes was significantly higher during the first and third waves, dominated by unsequenced variants and the Delta variant, respectively. Postnatal transmission accounted for most neonatal infections and was more frequent during the Omicron period. However, the paucity of symptoms in infected neonates should lead us not to separate the dyad.

From 2020 to today, considerable knowledge on SARS-CoV-2 has been collected, even on pregnant women and their fetuses and newborns, and clinical guidelines have been written and implemented worldwide. Vaccination has considerably improved outcomes, but hesitancy amongst pregnant patients and the emergence of variants remain challenging, and SARS-CoV-2 positivity during pregnancy continues to be associated with an increased risk of maternal complications, premature delivery, and higher neonatal mortality and morbidity. A body of data now exists on the effect of SARS-CoV-2 during pregnancy on early neonatal outcomes, medical education in obstetrics and pediatrics, and longer-term developmental outcomes. This review aimed to present important findings on clinical outcomes and health recommendations for neonate born from a SARS-CoV-2-positive mother in order to summarize effective preventive healthcare guidelines.