Reduction in preterm births during the COVID-19 lockdown in Ireland: a natural experiment allowing analysis of data from the prior two decades
Authors: Philip RK , Purtill H , Reidy E , Daly M , Imcha M , McGrath D , O’Connell NH , Dunne CP 
Published: June 2020

AbstractBackgroundAetiology of preterm birth (PTB) is heterogeneous and preventive strategies remain elusive. Socio-environmental measures implemented as Ireland’s prudent response to the SARS-CoV-2 virus (COVID-19) pandemic represented, in effect, a national lockdown and have possibly influenced the health and wellbeing of pregnant women and unborn infants. Cumulative impact of such socio-environmental factors operating contemporaneously on PTB has never been assessed before.MethodsRegional PTB trends of very low birth weight (VLBW) infants in one designated health area of Ireland over two decades were analysed. Poisson regression and rate ratio analyses with 95% CI were conducted. Observed regional data from January – April 2020 were compared to historical regional and national data and forecasted national figures for 2020.ResultsPoisson regression analysis found that the regional historical VLBW rate per 1000 live births for January to April, 2001-2019 was 8.18 (95% CI: 7.21, 9.29). During January to April 2020, an unusually low VLBW rate of just 2.17 per 1000 live births was observed. The rate ratio of 3.77 (95% CI: 1.21, 11.75), p = 0.022, estimates that for the last two decades there was, on average, 3.77 times the rate of VLBW, compared to the period January to April 2020 during which there is a 73% reduction. National Irish VLBW rate for 2020 is forecasted to be reduced to 400 per 60,000 births compared to the historical 500-600 range.ConclusionAn unprecedented reduction in PTB of VLBW infants was observed in one health region of Ireland during the COVID-19 lockdown. Potential determinants of this unique temporal trend reside in the summative socio-environmental impact of the COVID-19 dictated lockdown. Our findings, if mirrored in other regions that have adopted similar measures to combat the pandemic, demonstrate the potential to evaluate these implicated interdependent behavioural and socio-environmental modifiers to positively influence PTB rates globally.Key QuestionsWhat is already known?Premature birth is an important contributor for under-five mortality globally.Currently there is no broadly accepted and effective strategy to prevent the birth of premature very low birth weight infants.Impact of socio-environmental and maternal behavioural modifications on the incidence of preterm birth has not been assessed.What are the new findings?COVID-19-triggered national lockdown in Ireland created an opportunity to study the cumulative influence of socio-environmental modifications on pregnant mothers.An unprecedented 73% reduction in the rate of very low birth weight deliveries was noted in one designated health region of Ireland during January to April of 2020 in comparison to the preceding 20 year timeframe.Our observations, if nationally mirrored, indicate that birth rate of very low birth weight premature infants in Ireland is forecasted to decrease considerably in 2020.What do the new findings imply?Socially rooted modifiers such as family support, work related stress and commuting, environmental pollution, infection avoidance, sleep and nutritional support, adequate exercise, reduced exposure to tobacco and illicit drugs, avoidance of financial strain, all cumulatively could contribute to reduce preterm birth rate.Our observations, if reflected in other countries that adopted COVID-19-prompted lockdown measures, would redefine the antecedents that trigger the yet poorly understood pathways leading to preterm births.Prematurity rate would be the most important ‘curve to bend’ in the context of reducing infant mortality globally and thus promote the achievement of sustainable development goals for children.