Increase in preterm stillbirths and reduction in iatrogenic preterm births for fetal compromise: a multi-centre cohort study of COVID-19 lockdown effects in Melbourne, Australia

Abstract

Objectives: The COVID-19 pandemic has been associated with a worsening of perinatal outcomes in many settings due to the combined impacts of maternal COVID-19 disease, disruptions to maternity care, and overloaded health systems. In 2020, Melbourne endured a unique natural experiment where strict lockdown conditions were accompanied by very low COVID-19 case numbers and the maintenance of health service capacity. The aim of this study was to compare stillbirth and preterm birth rates in women who were exposed or unexposed to lockdown restrictions during pregnancy. Design: Retrospective multi-centre cohort study of perinatal outcomes before and during COVID-19 lockdown Setting: Birth outcomes from all 12 public maternity hospitals in metropolitan Melbourne Inclusion criteria: Singleton births without congenital anomalies from 24 weeks gestation. The lockdown-exposed cohort were those women for whom weeks 20- 40 of gestation would have occurred during the lockdown period of 23 March 2020 to 14 March 2021. The control cohort comprised all pregnancies in the corresponding periods one and two years prior to the exposed cohort. Main outcome measures. Odds of stillbirth, preterm birth (PTB), birth weight less than 3rd centile, and iatrogenic PTB for fetal compromise, adjusting for multiple covariates. Results: There were 24,017 births in the exposed and 50,017 births in the control group. There was a significantly higher risk of preterm, but not term, stillbirth in the exposed group compared with the control group (0.26% vs 0.18%, aOR 1.49, 95%CI 1.08 to 2.05, P = 0.015). There was also a significant reduction in preterm birth < 37 weeks (5.93% vs 6.23%, aOR 0.93, 95%CI 0.87 to 0.99, P=0.03), largely mediated by a reduction in iatrogenic PTB for live births (3.01% vs 3.27%, aOR 0.89, 95%CI 0.81 to 0.98, P = 0.015), including iatrogenic PTB for suspected fetal compromise (1.25% vs 1.51%, aOR 0.79, 95%CI 0.69 to 0.91, P= 0.001). There was no significant difference in the spontaneous PTB rate between the exposed and control groups (2.69% vs 2.82%, aOR 0.94, 95%CI 0.86 to 0.1.03, P=0.25). Conclusions: Lockdown restrictions in a high-income setting with low rates of COVID-19 disease were associated with a significant increase in preterm stillbirths and a significant reduction in iatrogenic PTB for suspected fetal compromise.

Possible toxicity of chronic carbon dioxide exposure associated with mask use, particularly in pregnant women, children and adolescents -a scoping review

“…However, current data on the new Delta variant, imply a possible slightly higher risk of stillbirths (prepandemic stillbirth rate of 0.59% versus 0.98% in COVID-19-affected deliveries and 2.70% during the Delta period), but the evaluation was not able to separate SARS-CoV2 exposure from higher mask exposure in those women [101]. Interestingly, recent data from Australia shows that lockdown restrictions and other measures (including masks that have been mandatory in Australia), in the absence of high rates of COVID-19 disease, were associated with a significant increase in preterm stillbirths [102]. May there be also a link between the pandemic driven excessive mask-use and the fact that 42% of female USA surgeons surveyed between November 2020 and February 2021 [103] lost a pregnancy according to a recent study?…”

“…There is circumstantial evidence that popular mask use may be related to current observations of a significant rise of 28% to 33% in stillbirths worldwide and a reduced verbal, motor and overall cognitive performance of two full standard deviations in scores in children born during the pandemic [99,[102][103][104][105]108]. Assuming that time is a toxicological variable equivalent to dose [52,53] long term everyday mask use cannot be claimed as harmless, as exposure to smaller daily doses will not be much different from exposure to a single high dose.…”

“…Reliable studies on possible carbon dioxide re-breathing while wearing a mask in real-world scenarios are necessary to exclude possible damaging effects [99,[102][103][104][105]108]. Therefore, health authorities should organise and perform further toxicological studies focusing on masks in specific user groups according to Good-Clinical-Practice and Good-Laboratory-Practice.…”