Impact of COVID-19 mitigation measures on the incidence of preterm birth: a national quasi-experimental study

Abstract

Background Preterm birth is the leading cause of child mortality globally, with many survivors experiencing long-term adverse consequences. Preliminary evidence suggests that numbers of preterm births greatly reduced following implementation of policy measures aimed at mitigating the effects of the COVID-19 pandemic. We aimed to study the impact of the COVID-19 mitigation measures implemented in the Netherlands in a stepwise fashion on March 9, March 15, and March 23, 2020, on the incidence of preterm birth.Methods We used a national quasi-experimental difference-in-regression-discontinuity approach. We used data from the neonatal dried blood spot screening programme (2010−20) cross-validated against national perinatal registry data. Stratified analyses were done according to gestational age subgroups, and sensitivity analyses were done to assess robustness of the findings. We explored potential effect modification by neighbourhood socioeconomic status, sex, and small-for-gestational-age status. FindingsData on 1 599 547 singleton neonates were available, including 56 720 births that occurred after implementation of COVID-19 mitigation measures on March 9, 2020. Consistent reductions in the incidence of preterm birth were seen across various time windows surrounding March 9 (± 2 months [n=531 823] odds ratio [OR] 0•77, 95% CI 0•66-0•91, p=0•0026; ± 3 months [n=796 531] OR 0•85, 0•73-0•98, p=0•028; ± 4 months [n=1 066 872] OR 0•84, 0•73-0•97, p=0•023). Decreases in incidence observed following the March 15 measures were of smaller magnitude, but not statistically significant. No changes were observed after March 23. Reductions in the incidence of preterm births after March 9 were consistent across gestational age strata and robust in sensitivity analyses. They appeared confined to neighbourhoods of high socioeconomic status, but effect modification was not statistically significant.Interpretation In this national quasi-experimental study, initial implementation of COVID-19 mitigation measures was associated with a substantial reduction in the incidence of preterm births in the following months, in agreement with preliminary observations elsewhere. Integration of comparable data from across the globe is needed to further substantiate these findings and start exploring underlying mechanisms.

Trends in intensive neonatal care during the COVID-19 outbreak in Japan

“…These results at least suggest that the number of high-risk newborns requiring intensive neonatal care was decreased during this outbreak, even though the possibility of the hospitals' incapability of providing intensive neonatal care remains. Combined with consistent findings in three early reports in Europe, [1][2][3] our study reinforces the hypothesis that changes in lifestyles at the maternal and community levels during the COVID-19 outbreak (movement restriction and the increased focus on infection prevention measures) might have had a positive secondary effect on maternal or fetal conditions, possibly through reduced rates of intrauterine infections or alleviated maternal physical stress. Our findings reappraise the importance of arranging the prenatal living environment to protect newborns and mothers.…”

Prematurity Rates During the Coronavirus Disease 2019 (COVID-19) Pandemic Lockdown in Melbourne, Australia

“…We confirm an association between lockdown and reduced preterm birth rates. 1 – 3 The reduction that occurred was stronger in medically indicated than in spontaneous prematurity and, reassuringly, without increases in stillbirth or undetected small-for-gestational-age neonates. Conversely, we also found a decrease in stillbirth rates during lockdown.…”

“…Preliminary international data suggest a decrease in prematurity during the coronavirus disease 2019 (COVID-19) pandemic, 1 – 3 potentially due to the effect of lockdown. Others could not confirm this observation.…”

Lack of changes in preterm delivery and stillbirths during COVID-19 lockdown in a European region

“…Three studies in Europe have reported a reduction in prematurity rates during the COVID-19 pandemic, suggesting that contingency measures could have an impact on prematurity rates [3][4][5]. Whether the behavior of prematurity rates is consistent with and in a similar proportion to what is seen in other parts of Europe is not known.…”