Program Schedule

The Impact of Early Life Antibiotic Exposure on Childhood Weight Gain

Session: Poster Abstract Session: Pediatric Antimicrobial Stewardship
Thursday, October 9, 2014
Room: The Pennsylvania Convention Center: IDExpo Hall BC

Antibiotic exposure has been shown to promote weight gain in livestock and has been associated with increased adiposity and altered metabolism in experimental animal models, mediated by alterations in the gut microbiome. Infancy and early childhood represent both an influential period of growth trajectory and a time during which antibiotic exposure is common and often inappropriate. Therefore, we sought to determine the impact of real world, early life antibiotic exposures on childhood weight gain.


A longitudinal, retrospective study was conducted using a socioeconomically and racially diverse pediatric healthcare network serving > 200,000 children at 31 practices. We included children born between 2001 and 2011 who presented for a preventive health visit in the first 14 days of life and had at least 2 additional visits in the first year. We excluded children born < 35 weeks gestational age; birthweight <2000 grams or below 5% for gestational age; with chronic medical conditions, prophylactic antibiotic use, or frequent steroid use. Exposures included all systemic antibiotic exposures in the first 6 months of life. The primary outcome was weight through age 8, standardized to WHO/CDC reference populations. A longitudinal mixed effects model was used to assess the association between standardized weight and age by antibiotic exposure interaction, adjusting for sex, race, insurance type, birthweight, preventive health care compliance, household size, birth year, baseline height and primary care practice site.  A second analysis, including sets of twins where only one twin had early antibiotic exposure, used a longitudinal mixed effects model to assess the association between paired weight difference and age, adjusting for differences in sex, birthweight, and baseline height.


Of 38,756 children included in the analysis, 5,312 (13.7%) received antibiotics in the first 6 months of life. After adjustment for clinical and demographic variables, antibiotic exposure was associated with a decrease of 0.03 in weight z-score per year (p<0.001). Of 47 sets of twins discordant in early antibiotic use, antibiotic exposure was not associated with a change in weight (p=0.59).


Using data from a large birth cohort, infant antibiotic exposure did not increase early childhood weight gain.

Jeffrey S. Gerber, MD, PhD1, Elizabeth Prout, MD, MSCE2, Rachael Ross, MPH3, Matthew Bryan, PhD4, Robert Grundmeier, MD5, Evanette Burrows6, Carrie Daymont, MD, MSCE7, Virginia Stallings, MD6 and Theoklis Zaoutis, MD, MSCE8, (1)Department of Pediatrics, Division of Infectious Diseases, The Children's Hospital of Philadelphia, Philadelphia, PA, (2)Division of Gastroenterology, Hepatology, and Nutrition, Children's Hospital of Philadelphia, Philadelphia, PA, (3)The Children's Hospital of Philadelphia, Philadelphia, PA, (4)Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, (5)General Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA, (6)Children's Hospital of Philadelphia, Philadelphia, PA, (7)University of Manitoba, Winnipeg, MB, Canada, (8)Division of Infectious Diseases, Center for Pediatric Clinical Effectiveness, the Children's Hospital of Philadelphia, Philadelphia, PA, The Children's Hospital of Philadelphia, Philadelphia, PA


J. S. Gerber, None

E. Prout, None

R. Ross, None

M. Bryan, None

R. Grundmeier, None

E. Burrows, None

C. Daymont, None

V. Stallings, None

T. Zaoutis, Merck: Investigator, Research grant
Merck: Consultant, Consulting fee
Pfizer: Consultant, Consulting fee
Astellas: Consultant, Consulting fee

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