Assessment of materno-foetal transmission of SARS-CoV-2: A prospective pilot study.

Background: The issue of vertical transmission of SARS-CoV-2 infection to the foetus has not yet been resolved. Its main reason is lack of a bigger study to analyse this question. The evidence of the affection of the foetus during antenatal or intrapartum period is limited to some anecdotal reports. To look for the possibility of vertical transmission of Severe Acute Respiratory Syndrome - Corona Virus-2 (SARS-CoV-2) infection to the foetus, this prospective pilot study was conducted at a tertiary health care COVID-19 designated centre of Armed Forces.

Methods: This study was conducted during 01 June 2020 and 15 October 2020 and included 54 covid-positive pregnant mothers. During delivery, amniotic fluid and cord blood samples were collected in a sterile manner. Amniotic fluid samples were not collected during vaginal deliveries as chances of contamination was very high. These samples were tested for the presence of SARS-CoV-2 gene by Reverse Transcriptasee Polymerase Chain Reaction (RT-PCR) test, and the results were analysed. Newborns were allowed to room in with mother, and they underwent throat and nasal swab RT-PCR testing of covid within 24-48 h of delivery.

Results: A total of 1520 pregnant mothers underwent RT-PCR test during the study period. Total positivity rate among our pregnant women was 2.8%. Out of 54 covid-positive women during the study period, amniotic fluid RT-PCR tests were carried out for 43 women, and cord blood was tested for 45 women.

Conclusion: RT-PCR test of amniotic fluid, cord blood and nasal and throat swab of all newborns delivered by SARS-CoV-2-positive pregnant women were negative. Based on our study, the possibility of intrauterine vertical transmission of SARS-CoV-2 infection appears to be unlikely.