Population-Level Study on Fetal Deaths and Preterm Births during SARS-CoV-2 Pandemic in the State of Michigan

The aim of the study is to explore the effect of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic on preterm birth at different gestational ages and fetal death in the state of Michigan.

Data on live births and fetal deaths in the state of Michigan from March to November in the years 2017 through 2020 were obtained from Michigan Department of Health and Human Services (MDHHS). Preterm birth rate, fetal death rate (per 1,000 live births) overall and stratified by race and maternal comorbidities during the period of pandemic (March-November 2020) were compared with the same period (March-November) in the prepandemic years (2017-2019).

Of 328,879 live births and 1,470 fetal deaths during the study period, 77,983 live births and 242 fetal deaths were reported in 2020. Compared with prepandemic years, fetal death rate per 1,000 live births was significantly lower in 2020 (3.1 vs. 4.7 [2017], 5.2 [2018], 4.4 [2019], p-value <0.001). The adjusted risk for fetal death in 2020 was decreased (odds ratio [OR] = 0.64 [95% confidence interval (CI): 0.56-0.74], p <0.0001), compared with prepandemic years. Fetal death was significantly associated with African-American race, pregnancy hypertension and prepregnancy diabetes. No significant difference in the proportion of preterm births (<37 weeks' gestation) was noted between pandemic and prepandemic years (9.9 vs. 10.0%, p = 0.50). There was no significant difference in the risk of preterm birth across gestational age strata (<28, 28-31^6/7, 32-36^6/7, 37-41^6/7, and >42 weeks) between pandemic and prepandemic years on multinomial analysis. Significant associations with preterm birth across all years included African American race, lower level of maternal education, pregnancy-induced hypertension, chronic hypertension, prepregnancy diabetes, congenital anomalies, previous preterm birth, and prolonged rupture of membranes >12 hours.

Fetal death rate was significantly lower whereas preterm births remained unchanged during pandemic in comparison with prepandemic years in the state of Michigan.

· A decrease in fetal death rate was noted during SARS CoV-2 pandemic in the State of Michigan.. · Overall state-wide rates of preterm birth did not change in 2020, compared to previous years.. · Significant risk factors associated with preterm birth and fetal deaths did not differ between prepandemic and pandemic years..