ABSTRACT
Background: Melbourne, Australia, recorded one of the longest and most stringent pandemic lockdowns in 2020, which was associated with an increase in preterm stillbirths among singleton pregnancies. Twin pregnancies may be particularly susceptible to the impacts of pandemic disruptions to maternity care due to their higher background risk of adverse perinatal outcomes. Objective: To compare the rates of adverse perinatal outcomes in twin pregnancies exposed and unexposed to lockdown restrictions in Melbourne. Study Design: Multicenter retrospective cohort study of all twin pregnancies birthing in public maternity hospitals in Melbourne. We compared perinatal outcomes between a pre-pandemic group ('unexposed') and two lockdown-exposed groups: exposure 1 from 22 March 2020 to 21 March 2021 and exposure 2 from 22 March 2021 to 27 March 2022. We analyzed routinely-collected maternity data on all twin births >20 weeks where outcomes were available for both infants. The primary outcomes were rates of preterm birth<37 weeks and all-cause stillbirth. Multivariable log-binomial regression models were used to compare perinatal outcomes between the pre-pandemic group and women in whom weeks 20+0 to 40+0 of their pregnancy occurred entirely during each lockdown-exposure period. Perinatal outcomes were calculated per infant; maternal outcomes were calculated per pregnancy. Results: We included 2267 women birthing twins. Total preterm births<37 weeks were significantly lower in the exposure 1 group compared with the pre-pandemic group (63.1% vs 68.3% respectively; adjusted risk ratio, aRR 0.92 95% CI 0.87-0.98, p=0.01). This was driven by both fewer iatrogenic preterm births (44.1% vs 48.1%; aRR 0.97 95% CI 0.92-1.03, p=0.39) and fewer spontaneous preterm births (18.9% vs 20.3%; aRR 0.95 95% CI 0.90-0.99, p=0.04). There were also significantly lower rates of preterm birth<34 weeks in the exposure 1 group compared with the pre-pandemic group (19.9% vs 23.0%, aRR 0.93 95% CI 0.89-0.98 p=0.01). Total iatrogenic births for fetal compromise were significantly lower (13.4% vs 20.4%; aRR 0.94 95% CI 0.89-0.98, p=0.01). There were fewer special care nursery admissions (38.5% vs 43.4%; aRR 0.91 95% CI 0.87-0.95, p<0.001). There was no associated difference in all-cause stillbirths (1.5% vs 1.6%; aRR 1.00 95% CI 0.99-1.01, p=0.82), adjusted stillbirths, birthweight<3rd centile (5.7% vs 6.0%; aRR 1.00, 95% CI 0.98-1.02 p=0.74) or neonatal intensive care unit admissions in the exposure 1 group compared to the pre-pandemic group. In contrast, when comparing the pre-pandemic group with exposure 2 group, there was no significant difference in the rates of preterm birth<37 or <34 weeks (p>0.05). However, during exposure 2 the rate of preterm birth<28 weeks was significantly higher (7.2% vs 4.8%; aRR 1.03 95% CI 1.01-1.05, p=0.04) and infants were more likely to be admitted to a neonatal intensive care unit (25.0% vs 19.6%; aRR 1.06 95% CI 1.03-1.10, p<0.0001) compared with the pre-pandemic period. Conclusions: Melbourne's first lockdown-exposure period was associated with fewer twin preterm births<34 and <37 weeks without significant differences in stillbirths or adverse newborn outcomes. These lower rates were not sustained into the second exposure period. Pandemic conditions may provide important lessons for future antenatal care of twin pregnancies, including prevention of preterm birth and optimal timing of birth.
Subject(s)
Iatrogenic Disease , COVID-19 , Stillbirth , Abnormalities, Drug-InducedABSTRACT
Background: COVID-19 infection in pregnancy is associated with a higher risk of progression to severe disease, but vaccine uptake by pregnant women is hindered by persistent safety concerns. COVID-19 vaccination in pregnancy has been shown to reduce stillbirth, but its relationship with preterm birth is uncertain. Objective: The aim of this study was to investigate the sociodemographic characteristics associated with vaccine uptake in Melbourne, Australia, and to compare perinatal outcomes by vaccination status. Study design: Retrospective multicenter cohort study in Melbourne following the national recommendations for mRNA COVID-19 vaccination during pregnancy in June 2021. Routinely collected data from all 12 public maternity hospitals in Melbourne were extracted on births > 20 weeks gestation from 1st July 2021 to 31 March 2022. Maternal sociodemographic characteristics were analyzed from the total birth cohort. Perinatal outcomes were compared between vaccinated and unvaccinated women for whom weeks 20-43 of gestation fell entirely within the 9-month data collection period. The primary outcome was the rate of congenital anomaly in singleton infants >= 20 weeks gestation among women vaccinated during pregnancy. Secondary perinatal outcomes including stillbirth, preterm birth (spontaneous and iatrogenic), birthweight <= 3rd centile, and newborn intensive care unit admissions were examined for singleton infants >= 24 weeks gestation without congenital anomalies. We calculated the adjusted odds ratio of congenital anomalies and perinatal outcomes among vaccinated versus unvaccinated women using inverse propensity score weighting regression adjustment with multiple covariates; p< 0.05 was considered statistically significant. Results: Births from 32,536 women were analyzed: 17,365 (53.4%) were vaccinated and 15,171 (47.6%) were unvaccinated. Vaccinated women were significantly more likely to be older, nulliparous, non-smoking, not requiring an interpreter, of higher socioeconomic status, and vaccinated against pertussis and influenza. Vaccination status also varied by region of birth: compared with women born in Australia, women born in South and Eastern Europe, the Middle East, Africa and Oceania had lower adjusted odds of vaccination. There was no significant increase in the rate of congenital anomalies or birth weight <= 3rd centile in vaccinated women. Vaccinated women were significantly less like to have an infant with a major congenital anomaly compared with the unvaccinated group (2.4% vs 3.0%, aOR 0.72, 95%CI 0.56-0.94, p=0.02). This finding remained significant even when the analysis was restricted to women vaccinated before 20 weeks gestation. Vaccinated women had a significantly lower rate of stillbirth (0.2% vs 0.8%, aOR 0.18, 95%CI 0.09-0.37, P < 0.001. Vaccination was associated with a significant reduction in total preterm births < 37 weeks (5.1% vs 9.2%, aOR 0.60, 95% CI 0.51-0.71, p< 0.001), spontaneous preterm birth (2.4% vs 4.0%, aOR 0.73 95% CI 0.56-0.96, p=0.02) and iatrogenic preterm birth (2.7% vs 5.2%, aOR 0.52, 95%CI 0.41-0.65, p< 0.001). Conclusions COVID-19 Vaccine coverage was significantly influenced by known social determinants of health, which is likely to influence the strong association between COVID-19 vaccination and lower risks of stillbirth and preterm birth. We did not observe any adverse impacts of vaccination on fetal growth or development.
Subject(s)
COVID-19 , Stillbirth , Congenital AbnormalitiesABSTRACT
ObjectivesThe 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. DesignRetrospective multi-centre cohort study of perinatal outcomes before and during COVID-19 lockdown SettingBirth outcomes from all 12 public maternity hospitals in metropolitan Melbourne Inclusion criteriaSingleton 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 measuresOdds of stillbirth, preterm birth (PTB), birth weight < 3rd centile, and iatrogenic PTB for fetal compromise, adjusting for multiple covariates. ResultsThere 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). ConclusionsLockdown restrictions in a high-income setting, in the absence of high 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. Trial registrationThis study was registered as an observational study with the Australian and New Zealand Clinical Trials Registry (ACTRN12620000878976).
Subject(s)
Congenital Abnormalities , Attention Deficit and Disruptive Behavior Disorders , COVID-19 , StillbirthABSTRACT
Objectives To balance the costs and effects comparing a strict lockdown versus a flexible social distancing strategy for societies affected by Coronavirus-19 Disease (COVID-19). Design Cost-effectiveness analysis. Participants We used societal data and COVID-19 mortality rates from the public domain. Interventions The intervention was a strict lockdown strategy that has been followed by Denmark. Reference strategy was flexible social distancing policy as was applied by Sweden. We derived mortality rates from COVID-19 national statistics, assumed the expected life years lost from each COVID-19 death to be 11 years and calculated lost life years until 31st August 2020. Expected economic costs were derived from gross domestic productivity (GDP) statistics from each country's official statistics bureau and forecasted GDP. The incremental financial costs of the strict lockdown were calculated by comparing Sweden with Denmark using externally available market information. Calculations were projected per one million inhabitants. In sensitivity analyses we varied the total cost of the lockdown (range -50% to +100%). Main outcome measure Financial costs per life years saved. Results In Sweden, the number of people who died with COVID-19 was 577 per million inhabitants, resulting in an estimated 6,350 life years lost per million inhabitants. In Denmark, where a strict lockdown strategy was installed for months, the number of people dying with COVID-19 was on average 111 per million, resulting in an estimated 1,216 life years per million inhabitants lost. The incremental costs of strict lockdown to save one life year was US$ 137,285, and higher in most of the sensitivity analyses. Conclusions Comparisons of public health interventions for COVID-19 should take into account life years saved and not only lost lives. Strict lockdown costs more than US$ 130,000 per life year saved. As our all our assumptions were in favour of strict lockdown, a flexible social distancing policy in response to COVID19 is defendable.