(229) A national population cohort study of congenital abnormalities following SARS-CoV-2 infection and COVID-19 vaccination during pregnancy

Background: Evidence on associations between COVID-19 vaccination or SARS-CoV-2 infection and the risk of congenital anomalies is limited.

Objectives: We present findings from a national population cohort investigation aimed at estimating the association of SARS-CoV-2 infection and COVID-19 vaccination during pregnancy with the diagnosis of congenital abnormalities.

Methods: This retrospective cohort study utilized national population data. Individual-level data of mothers who delivered babies between January 1, 2021, and December 31, 2022, along with their infants, were obtained from the National Health Insurance System database (from January 1, 2021, to December 31, 2022). These data were linked with SARS-CoV-2 infection surveillance data (from October 8, 2020, to December 31, 2021) and the COVID-19 vaccination registry (from February 26, 2021, to March 31, 2022), customized for research purposes. Babies diagnosed with any type of congenital abnormality, according to the ICD-10 codes as defined by the European Surveillance of Congenital Anomalies classification, were identified. Odds ratios (ORs) for congenital abnormalities per SARS-CoV-2 infection and COVID-19 vaccination during pregnancy were calculated, adjusting for women's age, residential area, employment status, presence of disability, season of delivery, and the sex of the baby.

Results: Among a total of 296,754 mother and neonate pairs, 273 (0.1%) mothers experienced COVID-19 infection, and 3,502 (1.2%) mothers received COVID-19 vaccination during pregnancy. Approximately 12% (n=34,763) infants had at least one minor and major congenital abnormalities. The association between SARS-CoV-2 infection during pregnancy and congenital abnormalities was not evident (OR=0.78, 95% confidence interval [CI]: 0.58, 1.05). The OR of any type of congenital abnormality was 1.05 (95% CI: 0.96, 1.15) per COVID-19 vaccination during pregnancy. The ORs of any congenital abnormalities did not differ across different types of vaccines.

Conclusions: Our findings underscore the importance of ongoing monitoring and research to better understand the potential impacts of COVID-19 infection and vaccination on pregnancy outcomes. Further investigation with longer follow-up periods is warranted to validate these findings and inform public health strategies aimed at safeguarding maternal and fetal health during the COVID-19 pandemic.