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.

Clara Calvert, Meredith Brockway, Helga Zoega, Jessica E. Miller, Jasper V. Been, Adeladza Kofi Amegah, Amy Racine-Poon, Solmaz Eradat Oskoui, Ishaya I. Abok, Nima Aghaeepour, Christie D. Akwaowo, Belal N. Alshaikh, Adejumoke I. Ayede, Fabiana Bacchini, Behzad Barekatain, Rodrigo Barnes, Karolina Bebak, Anick Berard, Zulfiqar A. Bhutta, Jeffrey R. Brook, Lenroy R. Bryan, Kim N. Cajachagua-Torres, Marsha Campbell-Yeo, Dinh-Toi Chu, Kristin L. Connor, Luc Cornette, Sandra Cortés, Mandy Daly, Christian Debauche, Iyabode Olabisi F. Dedeke, Kristjana Einarsdóttir, Hilde Engjom, Guadalupe Estrada-Gutierrez, Ilaria Fantasia, Nicole M. Fiorentino, Meredith Franklin, Abigail Fraser, Onesmus W. Gachuno, Linda A. Gallo, Mika Gissler, Siri E. Håberg, Abbas Habibelahi, Jonas Häggström, Lauren Hookham, Lisa Hui, Luis Huicho, Karen J. Hunter, Sayeeda Huq, Ashish KC, Seilesh Kadambari, Roya Kelishadi, Narjes Khalili, Joanna Kippen, Kirsty Le Doare, Javier Llorca, Laura A. Magee, Maria C. Magnus, Kenneth K. C. Man, Patrick M. Mburugu, Rishi P. Mediratta, Andrew D. Morris, Nazeem Muhajarine, Rachel H. Mulholland, Livia Nagy Bonnard, Victoria Nakibuuka, Natasha Nassar, Sylvester D. Nyadanu, Laura Oakley, Adesina Oladokun, Oladapo O. Olayemi, Olanike A. Olutekunbi, Rosena O. Oluwafemi, Taofik O. Ogunkunle, Chris Orton, Anne K. Örtqvist, Joseph Ouma, Oyejoke Oyapero, Kirsten R. Palmer, Lars H. Pedersen, Gavin Pereira, Isabel Pereyra, Roy K. Philip, Dominik Pruski, Marcin Przybylski, Hugo G. Quezada-Pinedo, Annette K. Regan, Natasha R. Rhoda, Tonia A. Rihs, Taylor Riley, Thiago Augusto Hernandes Rocha, Daniel L. Rolnik, Christoph Saner, Francisco J. Schneuer, Vivienne L. Souter, Olof Stephansson, Shengzhi Sun, Emma M. Swift, Miklós Szabó, Marleen Temmerman, Lloyd Tooke, Marcelo L. Urquia, Peter von Dadelszen, Gregory A. Wellenius, Clare Whitehead, Ian C. K. Wong, Rachael Wood, Katarzyna Wróblewska-Seniuk, Kojo Yeboah-Antwi, Christopher S. Yilgwan, Agnieszka Zawiejska, Aziz Sheikh, Natalie Rodriguez, David Burgner, Sarah J. Stock, Meghan B. Azad