Design
This prospective multicenter cohort study was conducted between July 3rd 2020 and January 24th 2021 at Emek and Baruch-Padeh Medical Centers, two university-affiliated medical centers in north Israel. The study protocol was approved by the Local Institutional Review Boards (60-20-EMC and 90-20-POR). Informed consent was obtained from all individuals who participated in the study.
The study cohort consisted of pregnant women≄18 years old who had a positive nasopharyngeal swab for SARS-CoV-2, as determined by RT-PCR, during pregnancy.
Women were enrolled at admission to the delivery ward, before delivery, by one of the team investigators. After enrollment, SARS-CoV-2 anti-nucleocapsid-IgG, anti-spike-IgG and anti-spike-IgM levels in maternal and cord blood were measured near delivery. Nasopharyngeal samples were collected from the neonates in the Department of Neonatology and were subjected to SARS-CoV-2 PCR testing. Participants were excluded from the study if both cord blood serology tests and neonatal RT-PCR could not be obtained due to technical reasons.