Menu Close

Association between Maternal Obesity and Group B Streptococcus Colonization in a National U.S. Cohort


Venkatesh, Kartik K.; Vladutiu, Catherine J.; Strauss, Robert A.; Thorp, John M., Jr.; Stringer, Jeffrey S. A.; Stamilio, David M.; Hughes, Brenna L.; & Dotters-Katz, Sarah (2020). Association between Maternal Obesity and Group B Streptococcus Colonization in a National U.S. Cohort. Journal of Women's Health, 29(12), 1507-1512. PMCID: PMC7757598


Objective: To investigate the association between maternal obesity as measured by prepregnancy body mass index (BMI) and group B streptococcus (GBS) colonization.
Methods: We conducted a secondary analysis from the Consortium on Safe Labor Study (CSL) in the United States cohort study (2002-2008). Pregnant women with deliveries at ≥37 weeks of gestation who attempted labor were included (115,070 assessed deliveries). The association between maternal prepregnancy BMI, categorized as normal weight or below (<25 kg/m(2)), overweight (25 to <30 kg/m(2)), class I obesity (30 to <35 kg/m(2)), class II obesity (35 to <40 kg/m(2)), and class III obesity (≥40 kg/m(2)), and GBS colonization was modeled using logistic regression with generalized estimating equations. Models adjusted for maternal age, parity, race, pregestational diabetes, insurance status, study site/region, and year of delivery.
Results: The overall prevalence of GBS colonization was 20.5% (23,625/115,070), which increased with rising maternal BMI, normal weight 19.3% (13,543/70,098), overweight 20.8% (5,353/25,733), class I obesity 23.0% (2,596/11,275), class II obesity 26.1% (1,270/4,850), and class III obesity 27.7% (863/3,114). In multivariable analysis, increasing maternal obesity severity was associated with higher odds of GBS colonization, namely overweight (adjusted odds ratio [AOR]: 1.09, 95% confidence interval [CI]: 1.05-1.13), class I obesity (AOR: 1.20, 95% CI: 1.15-1.26), class II obesity (AOR: 1.42, 95% CI: 1.33-1.51), and class III obesity (AOR: 1.50; 95% CI: 1.38-1.62) compared with normal weight. In secondary analyses, these associations persisted when stratified by maternal race.
Conclusions: In a national U.S. sample, increasing maternal obesity severity as assessed by prepregnancy BMI was associated with a higher likelihood of maternal GBS colonization during pregnancy.


Reference Type

Journal Article

Year Published


Journal Title

Journal of Women's Health


Venkatesh, Kartik K.
Vladutiu, Catherine J.
Strauss, Robert A.
Thorp, John M., Jr.
Stringer, Jeffrey S. A.
Stamilio, David M.
Hughes, Brenna L.
Dotters-Katz, Sarah