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Am J Perinatol 2026; 43(02): 204-208
DOI: 10.1055/a-2599-4867
Original Article

Decreased Newborn Size following COVID-19 Infection during Pregnancy: The Role of Timing of Infection

Authors

  • Hannah Yang

    1   Central Michigan University College of Medicine, Mount Pleasant, Michigan

  • Eleanor Nguyen

    1   Central Michigan University College of Medicine, Mount Pleasant, Michigan

  • Yosra Elsayed

    1   Central Michigan University College of Medicine, Mount Pleasant, Michigan

  • Victoria Zablocki

    1   Central Michigan University College of Medicine, Mount Pleasant, Michigan

  • Beth A. Bailey 

    1   Central Michigan University College of Medicine, Mount Pleasant, Michigan

Funding None.
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Abstract

Objective

The objective of this study was to examine the effect of coronavirus disease 2019 (COVID-19) infection during pregnancy on birth outcomes, including the relationship between the trimester of COVID-19 infection and newborn size. Findings could be used to better inform appropriate management of COVID-19 during pregnancy.

Study Design

This retrospective chart review study included patients diagnosed with COVID-19 who received care at a single university-affiliated obstetrics practice. Pregnant patients with a diagnosis of COVID-19 between April 2022 and April 2023 were included in this study. Participant demographics and birth outcomes were extracted and analyzed.

Results

Our sample included 141 women who had COVID-19 during pregnancy, grouped based on the trimester of COVID-19 infection. In analyses adjusted for confounding background factors, those with a COVID-19 infection during the second trimester (n = 57) and third trimester (n = 50) had newborns with significantly decreased head circumference at birth compared with those infected during the first trimester (p < 0.05). In addition, compared with those with a COVID-19 infection during the first trimester, those who had COVID-19 during the third trimester had an average 1.3 cm decreased birth length.

Conclusion

In the current study, COVID-19 infection later in pregnancy, especially in the third trimester, significantly predicted decreased birth weight, length, and head circumference.

Key Points

  • COVID-19 infection may impact newborn size.

  • Third-trimester infection was most detrimental.

  • Late-term monitoring may be warranted.

Keywords

viral infection - COVID-19 - trimester - birth outcomes - newborn size


Publication History

Received: 19 March 2025

Accepted: 01 May 2025

Accepted Manuscript online:
05 May 2025

Article published online:
23 May 2025

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