COVID-19 and maternal and perinatal outcomes

Changes in preterm birth and stillbirth during COVID-19 lockdowns in 26 countries

Preterm birth (PTB) is the leading cause of infant mortality worldwide. Changes in PTB rates, ranging from -90% to +30%, were reported in many countries following early COVID-19 pandemic response measures ('lockdowns'). It is unclear whether this variation reflects real differences in lockdown impacts, or perhaps differences in stillbirth rates and/or study designs. Here we present interrupted time series and meta-analyses using harmonized data from 52 million births in 26 countries, 18 of which had representative population-based data, with overall PTB rates ranging from 6% to 12% and stillbirth ranging from 2.5 to 10.5 per 1,000 births. We show small reductions in PTB in the first (odds ratio 0.96, 95% confidence interval 0.95-0.98, P value <0.0001), second (0.96, 0.92-0.99, 0.03) and third (0.97, 0.94-1.00, 0.09) months of lockdown, but not in the fourth month of lockdown (0.99, 0.96-1.01, 0.34), although there were some between-country differences after the first month. For high-income countries in this study, we did not observe an association between lockdown and stillbirths in the second (1.00, 0.88-1.14, 0.98), third (0.99, 0.88-1.12, 0.89) and fourth (1.01, 0.87-1.18, 0.86) months of lockdown, although we have imprecise estimates due to stillbirths being a relatively rare event. We did, however, find evidence of increased risk of stillbirth in the first month of lockdown in high-income countries (1.14, 1.02-1.29, 0.02) and, in Brazil, we found evidence for an association between lockdown and stillbirth in the second (1.09, 1.03-1.15, 0.002), third (1.10, 1.03-1.17, 0.003) and fourth (1.12, 1.05-1.19, <0.001) months of lockdown. With an estimated 14.8 million PTB annually worldwide, the modest reductions observed during early pandemic lockdowns translate into large numbers of PTB averted globally and warrant further research into causal pathways.

Fewer Preterm Births in the First COVID-19 Pandemic Year? An Evaluation of the Berlin Perinatal Data for the Years 2017 to 2020

Introduction The study analyzes and interprets possible effects of the COVID-19 pandemic on the preterm birth rate. Research questions included: were there fewer preterm births in Berlin in 2020, the first year of the pandemic, compared to the three years before the pandemic? Were there differences in preterm birth rates grouped according to weeks of gestation? Method The perinatal data of all singleton pregnancies were evaluated with regard to birth rates in Berlin, and the numbers of preterm neonates born in the three pre-pandemic years from 2017 to 2019 were compared to the rate for 2020, the first year of the pandemic. Results The overall number of singleton pregnancies born in maternity hospitals and labor wards in Berlin decreased in the first year of the pandemic. The percentage of preterm neonates born before 37 + 0 weeks of gestation (GW) was significantly lower in 2020 compared to the three previous years, with significantly more preterm neonates born before 28 + 0 GW and significantly fewer preterm neonates born between 28 + 0 to 35 + 0 GW. In 2020, significantly fewer neonates born before 37 + 0 weeks of gestation were delivered by primary caesarean section. The incidence of induced births was approximately the same. Conclusions In the first year of the pandemic, a range of social, iatrogenic, and biological factors may have had an impact on preterm birth rates. A Germany-wide evaluation of perinatal data across different German federal states for the period 2020 to 2022 would offer the opportunity to identify the causes of this lower rate of preterm births and determine whether conclusions can be drawn from this which would affect future strategies to reduce preterm birth rates.

Effects of the SARS-CoV-2 pandemic on perinatal activity in Yorkshire and the Humber region during 2020: an interrupted time series analysis

OBJECTIVE

To assess the impact of public health measures taken during the COVID-19 pandemic on perinatal health indicators.

DESIGN

Interrupted time series analysis comparing periods of the pandemic with the previous 5 years.

SETTING

Yorkshire and the Humber region, England (2015-2020).

MAIN OUTCOME MEASURES

Relative risk (RR) of stillbirth, extreme preterm (EPT, <27 weeks' gestational age) delivery, hypoxic ischaemic encephalopathy (HIE) and meconium aspiration syndrome (MAS), antenatal transfer for threatened EPT delivery and postnatal transfer for EPT birth, HIE or MAS.

RESULTS

Stillbirths fell from 3.7/1000 deliveries prepandemic to 2.9/1000 afterwards; EPT births decreased from 2.5/1000 to 1.8/1000 live births. Following adjustment, during the first lockdown there were decreased antenatal transfers (RR 0.74, 95% CI 0.57 to 0.94) with non-statistically significant increased stillbirth (RR 1.08, 95% CI 0.78 to 1.51) and decreased EPT admissions (RR 0.88, 95% CI 0.60 to 1.29). Over the entire pandemic period, antenatal transfer (RR 0.64, 95% CI 0.55 to 0.76) and EPT birth (RR 0.73, 95% CI 0.56 to 0.94) decreased; stillbirths showed non-statistically significant increases overall (RR 1.21, 95% CI 0.98 to 1.49) but with increasing trend through the pandemic (RR 1.11, 95% CI 1.00 to 1.22). No changes were seen for HIE, MAS, postnatal transfers or in subgroup analyses by ethnicity.

CONCLUSIONS

Lower rates of antenatal transfer and extreme preterm birth were identified, alongside an apparent increase in stillbirth over time. The findings provide evidence that effects on perinatal activity related to the pandemic changed over time.

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

Background

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.

Objective

This study aimed to compare the stillbirth and preterm birth rates in women who were exposed or unexposed to lockdown restrictions during pregnancy.

Study Design

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.

Results

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 <37 weeks (5.68% vs 6.07%; adjusted odds ratio, 0.93; 95% confidence interval, 0.87–0.99; P=.02), which was largely mediated by a significant reduction in iatrogenic preterm birth (3.01% vs 3.27%; adjusted odds ratio, 0.91; 95% confidence interval, 0.83–0.99; P=.03), including iatrogenic preterm birth for fetal compromise (1.25% vs 1.51%; adjusted odds ratio, 0.82; 95% confidence interval, 0.71–0.93; P=.003). There were also significant reductions in special care nursery admissions during lockdown (11.53% vs 12.51%; adjusted odds ratio, 0.90; 95% confidence interval, 0.86–0.95; P<.0001). There was a trend to fewer spontaneous preterm births <37 weeks in the exposed group of a similar magnitude to that reported in other countries (2.69% vs 2.82%; adjusted odds ratio, 0.95; 95% confidence interval, 0.87–1.05; P=.32).

Conclusion

Lockdown restrictions in Melbourne, Australia were associated with a significant reduction in iatrogenic preterm birth for fetal compromise and a significant increase in preterm stillbirths. This raises concerns that pandemic conditions in 2020 may have led to a failure to identify and appropriately care for pregnant women at an increased risk of antepartum stillbirth. Further research is required to understand the relationship between these 2 findings and to inform our ongoing responses to the pandemic.