Increase in preterm stillbirths in association with reduction in iatrogenic preterm births during COVID-19 lockdown in Australia: a multicenter cohort study

• Published in: American journal of obstetrics and gynecology 2022-09, Vol.227 (3), p.491.e1-491.e17
• Main Authors: Hui, Lisa, Marzan, Melvin Barrientos, Potenza, Stephanie, Rolnik, Daniel L., Pritchard, Natasha, Said, Joanne M., Palmer, Kirsten R., Whitehead, Clare L., Sheehan, Penelope M., Ford, Jolyon, Mol, Ben W., Walker, Susan P.
• Format: Article
• Language: English
• Subjects: cohort studies; COVID-19; Original Research; pregnancy outcome; premature birth; stillbirth
• ISSN: 0002-9378; 1097-6868
• DOI: 10.1016/j.ajog.2022.04.022

The COVID-19 pandemic has been associated with a worsening of perinatal outcomes in many regions around the world. Melbourne, Australia, had one of the longest and most stringent lockdowns worldwide in 2020 while recording only rare instances of COVID-19 infection in pregnant women. This study aimed to compare the stillbirth and preterm birth rates in women who were exposed or unexposed to lockdown restrictions during pregnancy. This was a retrospective, multicenter cohort study of perinatal outcomes in Melbourne before and during the COVID-19 lockdown. The lockdown period was defined as the period from March 23, 2020 to March 14, 2021. Routinely-collected maternity data on singleton pregnancies ≥24 weeks gestation without congenital anomalies were obtained from all the 12 public hospitals in Melbourne. We defined the lockdown-exposed cohort as those women for whom weeks 20 to 40 of gestation occurred during the lockdown and the unexposed control group as women from the corresponding calendar periods 12 and 24 months before. The main outcome measures were stillbirth, preterm birth, fetal growth restriction (birthweight < third centile), and iatrogenic preterm birth for fetal compromise. We performed multivariable logistic regression analysis to compare the odds of stillbirth, preterm birth, fetal growth restriction, and iatrogenic preterm birth for fetal compromise, adjusting for multiple covariates. There were 24,817 births in the exposed group and 50,017 births in the control group. There was a significantly higher risk of preterm stillbirth in the exposed group than the control group (0.26% vs 0.18%; adjusted odds ratio, 1.49; 95% confidence interval, 1.08–2.05; P=.015). There was also a significant reduction in the preterm birth of live infants