Impacts of COVID-19 pandemic on preterm birth: a systematic review and meta-analysis

Abstract

Objectives

The coronavirus disease 2019 (COVID-19) pandemic has significantly affected healthcare systems and daily wellbeing. However, the reports of the indirect impacts of the pandemic on preterm birth remain conflicting. We performed a meta-analysis to examine whether the pandemic altered the risk of preterm birth.

Study Design

A systematic review and meta-analysis of the previous literature.

Methods

We searched MEDLINE and Embase databases until March 2022 using appropriate keywords and extracted 63 eligible studies that compared preterm between the COVID-19 pandemic period and the pre-pandemic period. A random-effects model was used to obtain the pooled odds of each outcome. The study protocol was registered with PROSPERO (No. CRD42022326717).

Results

The search identified 3827 studies, of which 63 reports were included. A total of 3,220,370 pregnancies during the COVID-19 pandemic period and 6,122,615 pregnancies during the pre-pandemic period were studied. Compared with the pre-pandemic period, we identified a significant decreased odds of preterm birth (PTB, < 37 weeks’ gestation) [pooled OR (95%CI) = 0.96 (0.94, 0.98); I ² = 78.7%; 62 studies] and extremely preterm birth (EPTB, < 28 weeks’ gestation) [pooled OR (95%CI) = 0.92 (0.87, 0.97); I ² = 26.4%; 25 studies] during the pandemic, while there was only a borderline significant reduction in the odds of very preterm birth (VPTB, < 32 weeks’ gestation) [pooled OR (95%CI) = 0.93 (0.86, 1.01); I ² = 90.1%; 33 studies] between the two periods. There was significant publication bias for PTB.

Conclusion

Pooled results suggested the COVID-19 pandemic was associated with preterm birth, even though there was only a borderline significant reduction for VPTB during the pandemic compared with the pre-pandemic period. Large studies showed conflicting results, and further research on whether the change is related to pandemic mitigation measures was warranted.