Risk of intrauterine transmission and pregnancy outcomes following SARS-CoV-2 infection in the first or second trimester: a prospective cohort study.

BACKGROUND

China encountered a nation-wide outbreak of SARS-CoV-2 transmission during December 2022-January 2023 after discontinuation of the strict zero-Covid-19 policy on December 7, 2022. However, data on its impact on early pregnancy was limited. We aimed to investigate the risk of intrauterine transmission and pregnancy outcomes following SARS-CoV-2 infection during the first or second trimester, and to assess the safety of post-infection amniocentesis.

METHODS

From January 31 to February 28, 2023, we prospectively invited all pregnant women who were referred for amniocentesis to perform chromosomal microarray analysis to participate in this study. Based on the infection time, the participants were divided into group one with Covid-19 in the first trimester and and group two with Covid-19 in the second trimester. Amniotic fluid samples were analyzed for SARS-CoV-2 RNA using qRT-PCR. Pregnancy and neonatal outcomes were assessed through obstetric ultrasound examination and follow-ups.

RESULTS

In total, 225 women with 239 fetuses (14 sets of twin pregnancy) underwent amniocentesis in the study period. Finally, 134 pregnant women (6 sets of twin pregnancy) were included. They were infected with SARS-CoV-2 at gestational age 3 to 25 weeks. Amniocentesis was performed at gestational age 17 to 33 weeks. None of the 140 amniotic fluid samples tested positive for SARS-CoV-2 RNA, indicating no intrauterine transmission. Rates of premature delivery (8.8%) and birth weight (3335.8 g vs. 3279.9 g, p = 0.607) did not differ significantly between the first and second trimester infection groups.

CONCLUSION

No evidence of vertical transmission or adverse pregnancy outcomes was observed following SARS-CoV-2 infection during the first or second trimesters. Amniocentesis beyond the acute phase of infection appears safe.