Neonatal Sepsis and Outcomes of Maternal Group B Streptococcus Colonization in Preterm Birth

Main Article Content

Chanikarn Rungvachira
Siriporn Trainak

Abstract

Objectives: To evaluate the association between maternal Group B Streptococcus (GBS) colonization in preterm birth and neonatal outcomes.


Materials and Methods: A single-center retrospective paired cohort study was conducted at Chonburi Hospital, Thailand, from January 2014 to December 2024. Pregnant women admitted with preterm labor and delivery who underwent recto-vaginal swab culture were included. Pregnant women were categorized into two group based on Group B streptococcus (GBS) cultured status. Maternal and neonatal outcomes were compared between group. For adjusted analyses, GBS-positive mothers were matched 1:1 with GBS-negative mothers by year of recto-vaginal swab collection and gestational age at delivery. Logistic regression was performed to identify independent risk factors for neonatal sepsis in paired cohort.


Results: Among 3,895 women with preterm delivery, 114 mothers (2.9%) were colonized with GBS, accounting for 123 neonates. In the unpaired analysis, neonatal sepsis did not differ significantly between neonates born to GBS-positive and GBS-negative mothers (33.9% vs. 36.5%, p = 0.556). The rate of stillbirth occurred more among GBS-positive mothers. In the paired cohort of 114 matched maternal pairs and their neonates, maternal GBS colonization was not independently associated with neonatal sepsis or other neonatal morbidities. Multivariable analysis identified lower gestational age and birth weight between 1.5–2.5 kg as an independent risk factors for neonatal sepsis.


Conclusion: Maternal GBS colonization in preterm birth was not an independent risk factor for neonatal sepsis. Neonatal sepsis was primarily related to prematurity-associated factors, while stillbirth was more frequent among GBS-positive mothers.

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Rungvachira, C.; Trainak, S. Neonatal Sepsis and Outcomes of Maternal Group B Streptococcus Colonization in Preterm Birth. Thai J Obstet Gynaecol 2026.
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References

Bradley E, Blencowe H, Moller AB, Okwaraji YB, Sadler F, Gruending A, et al. Born too soon: global epidemiology of preterm birth and drivers for change. Reprod Health 2025;22:105.

World Health Organization. “Healthy Beginnings, Hopeful Futures”: Thailand Marks World Health Day 2025 with Commitment to Strengthen Care for Preterm Infants. In; 2025.

Fund UNCs. Under-five mortality. In: UNICEF Data : Monitoring the situation of children and women; 2025.

Cunningham FG LK, Bloom SL, Dashe JS, Hoffman BL, Casey BM, Spong CY. Williams Obstetrics. 26th edition ed. New York: McGraw-Hill Education; 2022.

Kornwalai Kinpoon SC. The Incidence and Risk Factors for Preterm Delivery in Northeast Thailand. Thai Journal of Obstetrics and Gynaecology 2564;29:100-11.

Prevention of Group B Streptococcal Early-Onset Disease in Newborns: ACOG Committee Opinion, Number 797. Obstet Gynecol 2020;135:e51-e72.

Bianchi-Jassir F, Seale AC, Kohli-Lynch M, Lawn JE, Baker CJ, Bartlett L, et al. Preterm Birth Associated With Group B Streptococcus Maternal Colonization Worldwide: Systematic Review and Meta-analyses. Clin Infect Dis 2017;65:S133-s42.

Warrier LM, Joy S, C RR, Bashir RA. Group B Streptococcal Colonization among Pregnant Women and Neonates in a Tertiary Care Hospital in South India. Indian J Pediatr 2022;89:1187-94.

Dai W, Zhang Y, Xu Y, Zhu M, Rong X, Zhong Q. The effect of group B streptococcus on maternal and infants' prognosis in Guizhou, China. Biosci Rep 2019;39.

Lohrmann F, Hufnagel M, Kunze M, Afshar B, Creti R, Detcheva A, et al. Neonatal invasive disease caused by Streptococcus agalactiae in Europe: the DEVANI multi-center study. Infection 2023;51:981-91.

ราชวิทยาลัยสูตินรีแพทย์แห่งประเทศไทย. แนวทางเวชปฏิบัติ: การดูแลรักษาภาวะเจ็บครรภ์คลอดและถุงน้ำคร่ำรั่วก่อนกำหนด. กรุงเทพฯ; 2566. Report No.: OB 66-033.

ACOG. Methods for Estimating the Due Date. Washington, DC: American College of Obstetricians and Gynecologists; 2017. Report No.: Committee Opinion No. 700.

Chess PR. Avery’s Neonatology Board Review: Certification and Clinical Refresher. 1st edition ed. Philadelphia, PA: Elsevier; 2019.

Gomella TLC, M. Douglas; Eyal, Fabien G.; Tuttle, Deborah J. Neonatology: Management, Procedures, On-Call Problems, Diseases, and Drugs. 7th edition ed. New York: McGraw-Hill Education; 2013.

Sosa M, Eckert LO, Kachikis A. Understanding GBS infection in pregnancy: exploring adverse maternal and pregnancy outcomes and the prospect of a GBS vaccine. Therapeutic Advances in Infectious Disease 2025;12:20499361251343710.

Khamchiangta C BA, Srisupundit K. The prevalence of group B Streptococcus (GBS) colonization in pregnant women. Journal of the Medical Association of Thailand 2017;100:1162-6.

Chen X, Cao S, Fu X, Ni Y, Huang B, Wu J, et al. The risk factors for Group B Streptococcus colonization during pregnancy and influences of intrapartum antibiotic prophylaxis on maternal and neonatal outcomes. BMC Pregnancy Childbirth 2023;23:207.

Rick AM, Aguilar A, Cortes R, Gordillo R, Melgar M, Samayoa-Reyes G, et al. Group B Streptococci Colonization in Pregnant Guatemalan Women: Prevalence, Risk Factors, and Vaginal Microbiome. Open Forum Infect Dis 2017;4:ofx020.

Hall J, Adams NH, Bartlett L, Seale AC, Lamagni T, Bianchi-Jassir F, et al. Maternal Disease With Group B Streptococcus and Serotype Distribution Worldwide: Systematic Review and Meta-analyses. Clinical Infectious Diseases 2017;65:S112-S24.

Edwards JM, Watson N, Focht C, Wynn C, Todd CA, Walter EB, et al. Group B Streptococcus (GBS) Colonization and Disease among Pregnant Women: A Historical Cohort Study. Infectious Diseases in Obstetrics and Gynecology 2019;2019:5430493.

Lee J, Naiduvaje K, Chew KL, Charan N, Chan YH, Lin RT, et al. Preventing early-onset group B streptococcal sepsis: clinical risk factor-based screening or culture-based screening? Singapore Med J 2021;62:34-8.

Stoll BJ, Puopolo KM, Hansen NI, Sánchez PJ, Bell EF, Carlo WA, et al. Early-Onset Neonatal Sepsis 2015 to 2017, the Rise of Escherichia coli, and the Need for Novel Prevention Strategies. JAMA Pediatrics 2020;174:e200593-e.

Moftian N, Samad Soltani T, Mirnia K, Esfandiari A, Tabib MS, Rezaei Hachesu P. Clinical Risk Factors for Early-Onset Sepsis in Neonates: An International Delphi Study. Iran J Med Sci 2023;48:57-69.

Briggs-Steinberg C, Roth P. Early-Onset Sepsis in Newborns. Pediatrics In Review 2023;44:14-22.

Villamor-Martinez E, Lubach GA, Rahim OM, Degraeuwe P, Zimmermann LJ, Kramer BW, et al. Association of Histological and Clinical Chorioamnionitis With Neonatal Sepsis Among Preterm Infants: A Systematic Review, Meta-Analysis, and Meta-Regression. Front Immunol 2020;11:972.

Poku VO. Maternal mortality: The role of Mycoplasma hominis and its impact on neonatal health. Health Sciences Review 2022;4:100036.

Sung TJ. Ureaplasma infections in pre-term infants: Recent information regarding the role of Ureaplasma species as neonatal pathogens. Korean J Pediatr 2010;53:989-93.

Li S, Huang J, Chen Z, Guo D, Yao Z, Ye X. Antibiotic Prevention for Maternal Group B Streptococcal Colonization on Neonatal GBS-Related Adverse Outcomes: A Meta-Analysis. Frontiers in Microbiology 2017;Volume 8 - 2017.

Mahtab S, Madewell ZJ, Madhi SA, Wise A, Swart PJ, Velaphi S, et al. Stillbirths and Neonatal Deaths Caused by Group B Streptococcus in Africa and South Asia Identified Through Child Health and Mortality Prevention Surveillance (CHAMPS). Open Forum Infectious Diseases 2023;10.

Guo L, Han W, Su Y, Wang N, Chen X, Ma J, et al. Perinatal risk factors for neonatal early-onset sepsis: a meta-analysis of observational studies. J Matern Fetal Neonatal Med 2023;36:2259049.

Belachew A, Tewabe T. Neonatal sepsis and its association with birth weight and gestational age among admitted neonates in Ethiopia: systematic review and meta-analysis. BMC Pediatrics 2020;20:55.

Ocviyanti D, Wahono WT. Risk Factors for Neonatal Sepsis in Pregnant Women with Premature Rupture of the Membrane. J Pregnancy 2018;2018:4823404.

Eiamcharoenlap J, Samutchaikij T. Maternal Factors Associated with Early Onset Neonatal Sepsis in Preterm newborns at Maharat Nakhon Ratchasima Hospital. Thai Journal of Obstetrics and Gynaecology 2025;34:42-9.