ArticleLancet regional health. Americas2021
The association of COVID-19 infection in pregnancy with preterm birth: A retrospective cohort study in California.
Article in Lancet regional health. Americas, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 68 papers, 2 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
68 citing papers in PubMed, 2 syntheses or guidelines pooled it, 112 citations in OpenAlex.
- Perinatal and neonatal outcomes among women with multimorbidity during pregnancy globally: a systematic review.BMC pediatrics · 2026Pooled it
- COVID-19 vaccination during pregnancy: a systematic review and meta-analysis.BMC pregnancy and childbirth · 2023Pooled it
- Methodological considerations for investigating the impact of abortion restrictions on outcomes using aggregate panel data.American journal of epidemiology · 2026Article
- Mild SARS-CoV-2 maternal infection in mice induces transient offspring neurodevelopmental aberrance.Proceedings of the National Academy of Sciences of the United States of America · 2026Article
- Association between COVID-19 outbreak and preterm birth rates in a low-infection cohort from a tertiary Shanghai maternity center: a retrospective study.Frontiers in pediatrics · 2026Article
- Article
- Maternal and neonatal outcomes with different screening strategies for gestational diabetes mellitus: a retrospective cohort study.The journal of maternal-fetal & neonatal medicine : the official journal of the European Association of Perinatal Medicine, the Federation of Asia and Oceania Perinatal Societies, the International Society of Perinatal Obstetricians · 2025Article
- Severe acute respiratory syndrome coronavirus 2 and preterm birth, clinical implications-A register-based cohort study from Sweden.Pregnancy (Hoboken, N.J.) · 2025Article
- Neutrophils at the Maternal-Fetal Interface: Agents of Protection or Destruction?American journal of reproductive immunology (New York, N.Y. : 1989) · 2025Review
- Impact of COVID-19 Control Measures on Birth Outcomes in Ho Chi Minh City, Vietnam.Journal of preventive medicine and public health = Yebang Uihakhoe chi · 2025Article
- Association between SARS-CoV-2 infection during pregnancy and placental pathology assessed by histology and gene expression.Pregnancy (Hoboken, N.J.) · 2025Article
- The Spectrum of Hesitancy in COVID-19 Vaccine Uptake Among Pregnant Latinas on the United States-Mexico Border.Women's reproductive health (Philadelphia, Pa.) · 2025Article
- Perinatal Health and Healthcare Utilisation During the COVID-19 Pandemic: A Nationwide Interrupted Time Series Analysis.Paediatric and perinatal epidemiology · 2025Article
- Mothers and mosquitoes: climate change contributes to the spread of vector-borne pathogens posing a substantial threat to pregnant women.Seminars in immunopathology · 2025Review
- Associations of pregnancy timing relative to the COVID-19 pandemic, maternal SARS-CoV-2 infection, and adverse perinatal outcomes.Annals of epidemiology · 2025Article
- Maternal and Neonatal Outcomes in COVID-19-Positive Pregnant Women.Maternal-fetal medicine (Wolters Kluwer Health, Inc.) · 2025Article
- The Effectiveness and Influence of COVID-19 Vaccination on Perinatal Individuals and Their Newborns: An Updated Meta-Analysis.The Canadian journal of infectious diseases & medical microbiology = Journal canadien des maladies infectieuses et de la microbiologie medicale · 2025Review
- PostCOVID-19 Impact on Perinatal Outcomes.Diagnostics (Basel, Switzerland) · 2024Article
- COVID-19 diagnosis, vaccination during pregnancy, and adverse pregnancy outcomes of 865,654 women in England and Wales: a population-based cohort study.The Lancet regional health. Europe · 2024Article
- Risk and Protective Factors for Preterm Birth Among Racial, Ethnic, and Socioeconomic Groups in California.JAMA network open · 2024Article
8 more citing papers are in PubMed but not listed here.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
28 authors at 6 institutions in 1 country.
Funding
Abstract
introductionOur understanding of the association between coronavirus disease 19 (COVID-19) and preterm or early term birth among racially and ethnically diverse populations and people with chronic medical conditions is limited.
methodsWe determined the association between COVID-19 and preterm (PTB) birth among live births documented by California Vital Statistics birth certificates between July 2020 and January 2021 (n=240,147). We used best obstetric estimate of gestational age to classify births as very preterm (VPTB, <32 weeks), PTB (< 37 weeks), early term (37 and 38 weeks), and term (39-44 weeks), as each confer independent risks to infant health and development. Separately, we calculated the joint effects of COVID-19 diagnosis, hypertension, diabetes, and obesity on PTB and VPTB.
findingsCOVID-19 diagnoses on birth certificates increased for all racial/ethnic groups between July 2020 and January 2021 and were highest for American Indian/Alaska Native (12.9%), Native Hawaiian/Pacific Islander (11.4%), and Latinx (10.3%) birthing people. COVID-19 diagnosis was associated with an increased risk of VPTB (aRR 1.6, 95% CI [1.4, 1.9]), PTB (aRR 1.4, 95% CI [1.3, 1.4]), and early term birth (aRR 1.1, 95% CI [1.1, 1.2]). There was no effect modification of the overall association by race/ethnicity or insurance status. COVID-19 diagnosis was associated with elevated risk of PTB in people with hypertension, diabetes, and/or obesity.
interpretationIn a large population-based study, COVID-19 diagnosis increased the risk of VPTB, PTB, and early term birth, particularly among people with medical comorbidities. Considering increased circulation of COVID-19 variants, preventative measures, including vaccination, should be prioritized for birthing persons.
fundingUCSF-Kaiser Department of Research Building Interdisciplinary Research Careers in Women's Health Program (BIRCWH) National Institute of Child Health and Human Development (NICHD) and the Office of Research on Women's Health (ORWH) [K12 HD052163] and the California Preterm Birth Initiative, funded by Marc and Lynn Benioff.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.