Background Severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) infection has been linked to increased maternal and fetal morbidity and mortality, as evidenced by numerous studies. Given the potential exacerbation of autoimmune diseases during viral infections, maternal and fetal complications such as preterm birth, low birth weight, or preeclampsia, often observed in pregnancies involving autoimmune thyroiditis with hypothyroidism, may be further aggravated. This study seeks to ascertain whether the association between viral infection and hypothyroidism contributes to an increase in adverse pregnancy outcomes. Methods This study included a cohort of 145 pregnant women with SARS-CoV-2 infection, who delivered in the Department of Obstetrics and Gynecology of the University Emergency Hospital in Bucharest, Romania, between January 1, 2020, and December 31, 2022. The participants were divided into two groups depending on the presence of autoimmune thyroiditis with hypothyroidism. We examined the maternal and fetal demographic parameters, paraclinical laboratory parameters, and outcomes, aiming to identify disparities between the two groups. Results Among the 145 SARS-CoV-2-positive pregnant women, the prevalence of hypothyroidism was 8.96%, with 13 cases reported. In the hypothyroidism group, the mean age of coronavirus disease 2019 (COVID-19) patients was higher (34.07 ± 5.18 years vs. 29.25 ± 6.23 years), as was the number of cases of investigated pregnancies, 12 (92.31%) vs. 91 (68.94%). There was no statistically significant correlation observed between fetal weight at birth, one-minute Apgar score, neonatal intensive care unit (NICU) admission, or intrauterine growth restriction between the two groups. Nevertheless, a case of stillbirth was recorded in the hypothyroidism group. The presence of thyroid pathology did not exacerbate the progression of the viral infection, as evidenced by the absence of cases of preeclampsia, ICU admission, or SARS-CoV-2 pneumonia. Conversely, the presence of hypothyroidism in pregnant women with SARS-CoV-2 infection was associated with lower uric acid levels and a slight decrease in international normalised ratio (INR) values. Additionally, there was a significant negative association between uric acid levels and the one-minute Apgar score in the hypothyroidism group, while no such correlations were observed in the other group. Furthermore, there was a statistically significant correlation between intrauterine growth restriction and uric acid values, as well as between the one-minute Apgar score and INR parameters, in both groups. Conclusion The link between SARS-CoV-2 infection and hypothyroidism does not appear to increase the risk of preterm birth, intrauterine growth restriction, or low fetal weight at birth. However, it may be associated with a higher risk of stillbirth. The presence of hypothyroidism in pregnant women with COVID-19 correlates with lower maternal uric acid levels and a slight decrease in INR values. The one-minute Apgar score correlates with the level of uric acid in pregnant women with SARS-CoV-2 infection and hypothyroidism.
