TY - JOUR

T1 - Preterm birth, stillbirth and early neonatal mortality during the Danish COVID-19 lockdown

AU - Hedley, Paula L

AU - Hedermann, Gitte

AU - Hagen, Christian M

AU - Bækvad-Hansen, Marie

AU - Hjalgrim, Henrik

AU - Rostgaard, Klaus

AU - Laksafoss, Anna D.

AU - Hoffmann, Steen

AU - Jensen, Jørgen Skov

AU - Breindahl, Morten

AU - Melbye, Mads

AU - Hviid, Anders

AU - Hougaard, David M

AU - Krebs, Lone

AU - Lausten-Thomsen, Ulrik

AU - Christiansen, Michael

N1 - © 2021. The Author(s).

PY - 2022

Y1 - 2022

N2 - Using provisional or opportunistic data, three nationwide studies (The Netherlands, the USA and Denmark) have identified a reduction in preterm or extremely preterm births during periods of COVID-19 restrictions. However, none of the studies accounted for perinatal deaths. To determine whether the reduction in extremely preterm births, observed in Denmark during the COVID-19 lockdown, could be the result of an increase in perinatal deaths and to assess the impact of extended COVID-19 restrictions, we performed a nationwide Danish register-based prevalence proportion study. We examined all singleton pregnancies delivered in Denmark during the COVID-19 strict lockdown calendar periods (March 12-April 14, 2015-2020, N = 31,164 births) and the extended calendar periods of COVID-19 restrictions (February 27-September 30, 2015-2020, N = 214,862 births). The extremely preterm birth rate was reduced (OR 0.27, 95% CI 0.07 to 0.86) during the strict lockdown period in 2020, while perinatal mortality was not significantly different. During the extended period of restrictions in 2020, the extremely preterm birth rate was marginally reduced, and a significant reduction in the stillbirth rate (OR 0.69, 0.50 to 0.95) was observed. No changes in early neonatal mortality rates were found.Conclusion: Stillbirth and extremely preterm birth rates were reduced in Denmark during the period of COVID-19 restrictions and lockdown, respectively, suggesting that aspects of these containment and control measures confer an element of protection. The present observational study does not allow for causal inference; however, the results support the design of studies to ascertain whether behavioural or social changes for pregnant women may improve pregnancy outcomes. What is Known: • The aetiologies of preterm birth and stillbirth are multifaceted and linked to a wide range of socio-demographic, medical, obstetric, foetal, psychosocial and environmental factors. • The COVID-19 lockdown saw a reduction in extremely preterm births in Denmark and other high-income countries. An urgent question is whether this reduction can be explained by increased perinatal mortality. What is New: • The reduction in extremely preterm births during the Danish COVID-19 lockdown was not a consequence of increased perinatal mortality, which remained unchanged during this period. • The stillbirth rate was reduced throughout the extended period of COVID-19 restrictions.

AB - Using provisional or opportunistic data, three nationwide studies (The Netherlands, the USA and Denmark) have identified a reduction in preterm or extremely preterm births during periods of COVID-19 restrictions. However, none of the studies accounted for perinatal deaths. To determine whether the reduction in extremely preterm births, observed in Denmark during the COVID-19 lockdown, could be the result of an increase in perinatal deaths and to assess the impact of extended COVID-19 restrictions, we performed a nationwide Danish register-based prevalence proportion study. We examined all singleton pregnancies delivered in Denmark during the COVID-19 strict lockdown calendar periods (March 12-April 14, 2015-2020, N = 31,164 births) and the extended calendar periods of COVID-19 restrictions (February 27-September 30, 2015-2020, N = 214,862 births). The extremely preterm birth rate was reduced (OR 0.27, 95% CI 0.07 to 0.86) during the strict lockdown period in 2020, while perinatal mortality was not significantly different. During the extended period of restrictions in 2020, the extremely preterm birth rate was marginally reduced, and a significant reduction in the stillbirth rate (OR 0.69, 0.50 to 0.95) was observed. No changes in early neonatal mortality rates were found.Conclusion: Stillbirth and extremely preterm birth rates were reduced in Denmark during the period of COVID-19 restrictions and lockdown, respectively, suggesting that aspects of these containment and control measures confer an element of protection. The present observational study does not allow for causal inference; however, the results support the design of studies to ascertain whether behavioural or social changes for pregnant women may improve pregnancy outcomes. What is Known: • The aetiologies of preterm birth and stillbirth are multifaceted and linked to a wide range of socio-demographic, medical, obstetric, foetal, psychosocial and environmental factors. • The COVID-19 lockdown saw a reduction in extremely preterm births in Denmark and other high-income countries. An urgent question is whether this reduction can be explained by increased perinatal mortality. What is New: • The reduction in extremely preterm births during the Danish COVID-19 lockdown was not a consequence of increased perinatal mortality, which remained unchanged during this period. • The stillbirth rate was reduced throughout the extended period of COVID-19 restrictions.

KW - (MeSH): Gestational Age

KW - COVID-19

KW - Epidemics, Infant, Premature

KW - Infant, Extremely Premature

KW - Perinatal Death

KW - Stillbirth

U2 - 10.1007/s00431-021-04297-4

DO - 10.1007/s00431-021-04297-4

M3 - Journal article

C2 - 34783897

VL - 181

SP - 1175

EP - 1184

JO - Acta Paediatrica Hungarica

JF - Acta Paediatrica Hungarica

SN - 0340-6199

ER -