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

Area of Science:

• Obstetrics and Gynecology
• Infectious Diseases
• Public Health

Background:

• Group B Streptococcus (GBS) is a significant cause of neonatal infections.
• Maternal obesity is a growing public health concern with potential implications for pregnancy outcomes.
• Understanding risk factors for GBS colonization is crucial for effective prevention strategies.

Purpose of the Study:

• To examine the association between maternal prepregnancy body mass index (BMI) categories and the prevalence of GBS colonization.
• To determine if increasing severity of maternal obesity correlates with a higher likelihood of GBS colonization.
• To assess these associations across different racial groups.

Main Methods:

• Secondary analysis of the Consortium on Safe Labor Study (CSL) cohort (2002-2008) in the United States.
• Inclusion of 115,070 pregnant women delivering at ≥37 weeks gestation who attempted labor.
• Logistic regression with generalized estimating equations was used to model the association between BMI categories and GBS colonization, adjusting for covariates.

Main Results:

• Overall GBS colonization prevalence was 20.5%, increasing with maternal BMI categories.
• Compared to normal weight, adjusted odds ratios for GBS colonization were elevated for overweight (1.09), class I obesity (1.20), class II obesity (1.42), and class III obesity (1.50).
• These associations remained consistent across maternal racial strata.

Conclusions:

• Increasing maternal obesity severity, assessed by prepregnancy BMI, is significantly associated with a higher prevalence of GBS colonization.
• The findings highlight obesity as a potential risk factor for GBS colonization in pregnant women.
• Public health initiatives addressing maternal obesity may indirectly help reduce GBS colonization rates.