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Licensed Unlicensed Requires Authentication Published by De Gruyter December 18, 2020

Racial disparities in recurrent preterm delivery risk: mediation analysis of prenatal care timing

  • Khalidha Nasiri EMAIL logo , Erica E. M. Moodie and Haim A. Abenhaim



We estimated the degree to which the association between race and spontaneous recurrent preterm delivery is mediated by the timing of the first prenatal care visit.


A retrospective population-based cohort study was conducted using the U.S. National Center for Health Statistics Natality Files. We identified 644,576 women with a prior PTB who delivered singleton live neonates between 2011 and 2017. A mediation analysis was conducted using log-binomial regression to evaluate the mediating effect of timing of first prenatal care visit.


During the seven-year period, 349,293 (54.2%) White non-Hispanic women, 131,296 (20.4%) Black non-Hispanic women, 132,367 (20.5%) Hispanic women, and 31,620 (4.9%) Other women had a prior preterm delivery. The risk of late prenatal care initiation was higher in Black non-Hispanic women, Hispanic women, and Other women (women of other racial/ethnic backgrounds) compared to White non-Hispanic women, and the risk of preterm delivery was higher in women with late prenatal care initiation. Between 8 and 15% of the association between race and spontaneous recurrent preterm delivery acted through the delayed timing of the first prenatal care visit.


Racial disparities in spontaneous recurrent preterm delivery rates can be partly, but not primarily, attributed to timing of first prenatal care visit.

Corresponding author: Khalidha Nasiri, MSc, MD Candidate, Schulich School of Medicine, Western University, London, ON, Canada; Department of Epidemiology and Biostatistics, McGill University, Montreal, QC, Canada; and Center for Clinical Epidemiology and Community Studies, Jewish General Hospital, Montreal, QC, Canada, E-mail:


Khalidha Nasiri received funding from the Canadian Institutes of Health Research – Frederick Banting and Charles Best Canada Graduate Scholarship in support of her Master’s research. They were not involved in study design, collection, analysis and interpretation of the data, report writing, and in the decision to submit the article for publication.

  1. Research funding: None declared.

  2. Author contributions: All authors have accepted responsibility for the entire content of this manuscript and approved its submission.

  3. Competing interests: Khalidha Nasiri received funding from the Canadian Institutes of Health Research – Frederick Banting and Charles Best Canada Graduate Scholarship in support of her Master’s research. They were not involved in study design, collection, analysis and interpretation of the data, report writing, and in the decision to submit the article for publication. All other authors state no conflict of interest.

  4. Ethical approval: The Research Ethics Committee at the authors’ institution considered this study exempt from ethical approval because it is based on publicly available data.


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Supplementary Material

The online version of this article offers supplementary material (

Received: 2020-03-26
Accepted: 2020-12-02
Published Online: 2020-12-18
Published in Print: 2021-05-26

© 2020 Walter de Gruyter GmbH, Berlin/Boston

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