Antepartum stillbirth rates during the COVID-19 pandemic in Austria: A population-based study

Background The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 has had dramatic effects on the pregnant population worldwide, increasing the risk of adverse perinatal outcomes. Objective To assess the incidence of antepartum stillbirth (aSB) during the COVID-19 pandemic in Austria. Methods We collected epidemiological data from the Austrian Birth Registry and compared the rate of aSB (i.e., fetal death at or after 24(+0) gestational weeks) during the pandemic period (March-December 2020) and in the respective pre-pandemic months (2015-2019). Results In total, 65 660 pregnancies were included, of which 171 resulted in aSB at 33.7 +/- 4.8 gestational weeks. During the pandemic, the aSB rate increased from 2.49 parts per thousand to 2.60 parts per thousand (P = 0.601), in contrast to the significant decline in preterm deliveries at or before 37 gestational weeks from 0.61 parts per thousand to 0.56 parts per thousand (relative risk [RR] 0.93; 95% confidence interval [CI] 0.91-0.96; P < 0.001). During the first lockdown, the aSB rate significantly increased from 2.38 parts per thousand to 3.52 parts per thousand (P = 0.021), yielding an adjusted odds ratio of 1.57 (95% CI 1.08-2.27; P = 0.018). The event of aSB during the COVID-19 pandemic was strongly related with increased fetal weight and maternal obesity. Conclusion In Austria, there has been an overall increase in the incidence of aSB during the pandemic with a significant peak during the first lockdown.