Impact of COVID-19 and vaccination on first and second trimester screening results.

COVID-19 has been shown to affect pregnant women. Since pregnant women are at risk of this infection, vaccination against COVID-19 has been suggested as an imperative way to diminish rate of COVID-19 in this population. In the current observational study, we have collected data of first and second trimester screening (FTS and STS) from pregnant women who were infected with SARS-CoV-2 and/or vaccinated against COVID-19 during their pregnancy, and compared this data with a group of control pregnant women. The cohort included 4612 and 2426 women referred for FTS and STS, respectively. There was no significant difference in median values of Pregnancy-associated plasma protein A (PAPP-A) and human chorionic gonadotropin-beta subunit (βHCG) between infected women and controls. Moreover, these levels were not different between "Infected + vaccinated" and "Only vaccinated" groups. However, median values of PAPP-A and βHCG were higher in "Infected + vaccinated" and "Only vaccinated" groups compared with "Infected" and "Control" groups (P < 0.001). Median values of unconjugated Estriol (uE3) and βHCG markers were not different between "Only vaccinated" and "Control" groups, yet both markers were elevated in "Infected" and "Infected + vaccinated" groups compared with other groups. AFP values were higher in "Infected" group (P = 0.012). However, multiple of the median (MoM) and risk of open spina bifida (OSB) were not affected. Finally, median of calculated risk of trisomy 18 was lower in "Infected" and "Vaccinated" groups compared with controls (P = 0.007). Moreover, AstraZeneca and Sinopharm vaccines were associated with elevation of the calculated risk values of trisomy 21 and trisomy 18 (P < 0.001). While Sinopharm did not affect nuchal translucency (NT) and NT MoM (P = 0.13), AstraZeneca and Barakat increased and decreased these values, respectively (P values = 0.0027 and 0.015, respectively). Taken together, COVID-19 during pregnancy might be associated with some adverse obstetric outcomes. Besides, vaccination against this infection might affect the results of STS or FTS.