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 (ßHCG) 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 ßHCG 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 ßHCG 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.

Fine-tuning of routine combined first- trimester screening: The ratio of serum-free- beta-human chorionic gonadotropin (fß-hCG) to pregnancy-associated plasma protein-A (PAPP-A) could improve performance of Down syndrome screening program, a retrospective cohort study in Iran.

OBJECTIVES: To evaluate the performance of the current national screening policy for Down syndrome (DS) in Iran and suggest a more efficient protocol with a wealth of a large series of first-trimester screening (FTS) data obtained from Nilou medical laboratory. To fulfill this aim, detection rate (DR), positive screening rate (PSR), false negative rate (FNR) and odds of being affected given a positive results (OAPR) were calculated at different cutoff risk. In the latest update of DS screening program in Iran, there is no place for intermediate group to be further investigated. Next, we proposed a novel parameter namely the ratio of fß-hCG multiple of the median (MoM) value to PAPP-A MoM value to delicately categorize FTS results in a way that reduce FNR without imposing unnecessary anxious and extra money on most families. METHODS: The present investigation was conducted retrospectively on 197,210 pregnancies undergoing FTS for aneuploidies in Nilou medical laboratory, Tehran, Iran, from March 2015 to February 2016. RESULTS: Intermediate risk group is important as 23 out of 45 FN fell in the range 1:250 to 1:1100. By applying the proposed index, the ratio of fß-hCG MoM to PAPP-A MoM and subsequent decision about NIPT, 8 out of 23 FN cases in intermediate group could be detected. CONCLUSION: Compared with the current policy, our novel proposed approach had better performance and could be applied by the Iran National Health Service to improve the screening program guideline.