The international Perinatal Outcomes in the Pandemic (iPOP) study: Protocol

Sarah J. Stock, Helga Zoega, Meredith Brockway, Rachel H. Mulholland, Jessica E. Miller, Jasper V. Been, Rachael Wood, Ishaya I. Abok, Belal Alshaikh, Adejumoke I. Ayede, Fabiana Bacchini, Zulfiqar A. Bhutta, Bronwyn K. Brew, Jeffrey Brook, Clara Calvert, Marsha Campbell-Yeo, Deborah Chan, James Chirombo, Kristin L. Connor, Mandy DalyKristjana Einarsdóttir, Ilaria Fantasia, Meredith Franklin, Abigail Fraser, Siri Eldevik Håberg, Lisa Hui, Luis Huicho, Maria C. Magnus, Andrew D. Morris, Livia Nagy-Bonnard, Natasha Nassar, Sylvester Dodzi Nyadanu, Dedeke Iyabode Olabisi, Kirsten R. Palmer, Lars Henning Pedersen, Gavin Pereira, Amy Racine-Poon, Manon Ranger, Tonia Rihs, Christoph Saner, Aziz Sheikh, Emma M. Swift, Lloyd Tooke, Marcelo L. Urquia, Clare Whitehead, Christopher Yilgwan, Natalie Rodriguez, David Burgner, Meghan B. Azad, iPOP Study Team

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Preterm birth is the leading cause of infant death worldwide, but the causes of preterm birth are largely unknown. During the early COVID-19 lockdowns, dramatic reductions in preterm birth were reported; however, these trends may be offset by increases in stillbirth rates. It is important to study these trends globally as the pandemic continues, and to understand the underlying cause(s). Lockdowns have dramatically impacted maternal workload, access to healthcare, hygiene practices, and air pollution - all of which could impact perinatal outcomes and might affect pregnant women differently in different regions of the world. In the international Perinatal Outcomes in the Pandemic (iPOP) Study, we will seize the unique opportunity offered by the COVID-19 pandemic to answer urgent questions about perinatal health. In the first two study phases, we will use population-based aggregate data and standardized outcome definitions to: 1) Determine rates of preterm birth, low birth weight, and stillbirth and describe changes during lockdowns; and assess if these changes are consistent globally, or differ by region and income setting, 2) Determine if the magnitude of changes in adverse perinatal outcomes during lockdown are modified by regional differences in COVID-19 infection rates, lockdown stringency, adherence to lockdown measures, air quality, or other social and economic markers, obtained from publicly available datasets. We will undertake an interrupted time series analysis covering births from January 2015 through July 2020. The iPOP Study will involve at least 121 researchers in 37 countries, including obstetricians, neonatologists, epidemiologists, public health researchers, environmental scientists, and policymakers. We will leverage the most disruptive and widespread 'natural experiment' of our lifetime to make rapid discoveries about preterm birth. Whether the COVID-19 pandemic is worsening or unexpectedly improving perinatal outcomes, our research will provide critical new information to shape prenatal care strategies throughout (and well beyond) the pandemic.

Original languageEnglish
Article number21
Number of pages17
JournalWellcome Open Research
Publication statusPublished - Oct 2021


  • COVID-19
  • Global trends
  • Low birth weight
  • Pandemic lockdowns
  • Perinatal outcomes
  • Preterm birth
  • Stillbirth

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