Impact of the COVID-19 pandemic on preterm birth and stillbirth: A nationwide, population-based retrospective cohort study

OBJECTIVE: This study aimed to establish whether there was a decrease in the rate of prematurity in France after the beginning of lockdown (March 17, 2020) and whether there was an increase in the rate of stillbirths compared with 2017 to 2019. STUDY DESIGN: We included all births from January to September of each year from 2017 to 2020 from the national Programme de Médicalisation des Systèmes d’Information database: 496,171 newborns from women with singleton pregnancies and 15,441 newborns from women with multiple pregnancies were included for 2020. Concerning the 2017 to 2019 period, we included a mean of 518,798 newborns from women with singleton pregnancies and 16,441 newborns from women with multiple pregnancies per year. RESULTS: Between April to May 2017 to 2019 and April to May 2020, there was a decrease of - 7.53% in the rate of prematurity (from 5.31% to 4.91%; P < 0.01) for singleton pregnancies. Between these 2 periods, the rate of change was −12.90% between 22 and 27 WG (P = 0.03), +1.96% between 28 and 31 WG (P = 0.69), and −8.24% between 32 and 36 WG (P < 0.01). The decrease in the rate of prematurity was still observed after the end of lockdown (from June to September 2020). For multiple births, there was no decrease in prematurity between January to September 2017 to 2019 and January to September 2020: 50.14% vs. 50.36% (P = 0.63), respectively, for twins and 95.51% vs. 94.9% (P = 0.62), respectively, for high-order multiple pregnancies. In January to September, there were 363 stillbirths among singleton pregnancies in 2017 to 2019 and 114 in 2020 (0.00% change rate). Among the 1752 women with a diagnosis of SARS-CoV-2 infection with singleton pregnancies, the rate of prematurity was higher in 2020 than in 2017 to 2019 (9.93% vs. 5.32%; P < 0.01), regardless of the severity of prematurity (P < 0.05 for all). CONCLUSION: Large-scale socioenvironmental modifications like the lockdown in spring 2020 may be associated with beneficial effects on perinatal morbidity. We did not find an increase in the rate of stillbirth since the beginning of the pandemic. At this stage, the practical consequences are not obvious, but our results encourage further reflection regarding behaviors that could modify the risk of prematurity outside of the context of an epidemic.