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DOI: 10.1055/a-2599-4867
Decreased Newborn Size following COVID-19 Infection during Pregnancy: The Role of Timing of Infection
Funding None.

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
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COVID-19 infection may impact newborn size.
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Third-trimester infection was most detrimental.
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Late-term monitoring may be warranted.
Publication History
Received: 19 March 2025
Accepted: 01 May 2025
Accepted Manuscript online:
05 May 2025
Article published online:
23 May 2025
© 2025. Thieme. All rights reserved.
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References
- 1 Maudhoo A, Khalil A. Viral pulmonary infection in pregnancy - including COVID-19, SARS, influenza A, and varicella. Best Pract Res Clin Obstet Gynaecol 2022; 85 (Pt A): 17-25
- 2 Seif KE, Tadbiri H, Mangione M. et al. The impact of trimester of COVID-19 infection on pregnancy outcomes after recovery. J Perinat Med 2023; 51 (07) 868-873
- 3 Overton EE, Goffman D, Friedman AM. The epidemiology of COVID-19 in pregnancy. Clin Obstet Gynecol 2022; 65 (01) 110-122
- 4 Mosby LG, Rasmussen SA, Jamieson DJ. 2009 pandemic influenza A (H1N1) in pregnancy: a systematic review of the literature. Am J Obstet Gynecol 2011; 205 (01) 10-18
- 5 Abdullahi H, Elnahas A, Konje JC. Seasonal influenza during pregnancy. Eur J Obstet Gynecol Reprod Biol 2021; 258: 235-239
- 6 Fallach N, Segal Y, Agassy J. et al. Pregnancy outcomes after SARS-CoV-2 infection by trimester: a large, population-based cohort study. PLoS One 2022; 17 (07) e0270893
- 7 Bai Y, Tao X. Comparison of COVID-19 and influenza characteristics. J Zhejiang Univ Sci B 2021; 22 (02) 87-98
- 8 Villar J, Ariff S, Gunier RB. et al. Maternal and neonatal morbidity and mortality among pregnant women with and without covid-19 infection: the intercovid multinational cohort study. JAMA Pediatr 2021; 175 (08) 817-826
- 9 Lokken EM, Huebner EM, Taylor GG. et al; Washington State COVID-19 in Pregnancy Collaborative. Disease severity, pregnancy outcomes, and maternal deaths among pregnant patients with severe acute respiratory syndrome coronavirus 2 infection in Washington State. Am J Obstet Gynecol 2021; 225 (01) 77.e1-77.e14
- 10 Virk S, Gangu K, Nasrullah A. et al. Impact of Covid-19 on pregnancy outcomes across trimesters in the United States. Biomedicines 2023; 11 (11) 2886
- 11 Sertel E, Demir M. Evaluation of the effects of COVID-19 disease and the trimester in which the disease is diagnosed on obstetric and neonatal outcomes: a retrospective cohort study. J Obstet Gynaecol Res 2023; 49 (02) 614-624
- 12 Piekos SN, Roper RT, Hwang YM. et al. The effect of maternal SARS-CoV-2 infection timing on birth outcomes: a retrospective multicentre cohort study. Lancet Digit Health 2022; 4 (02) e95-e104
- 13 Regan AK, Moore HC, Sullivan SG, DE Klerk N, Effler PV. Epidemiology of seasonal influenza infection in pregnant women and its impact on birth outcomes. Epidemiol Infect 2017; 145 (14) 2930-2939
- 14 Yu W, Hu X, Cao B. Viral infections during pregnancy: the big challenge threatening maternal and fetal health. Matern Fetal Med 2021; 4 (01) 72-86
- 15 Racicot K, Mor G. Risks associated with viral infections during pregnancy. J Clin Invest 2017; 127 (05) 1591-1599
- 16 Liong S, Oseghale O, To EE. et al. Influenza A virus causes maternal and fetal pathology via innate and adaptive vascular inflammation in mice. Proc Natl Acad Sci U S A 2020; 117 (40) 24964-24973
- 17 Onwuzurike C, Diouf K, Meadows AR, Nour NM. Racial and ethnic disparities in severity of COVID-19 disease in pregnancy in the United States. Int J Gynaecol Obstet 2020; 151 (02) 293-295