Girls exposed to antibiotics during their first year of life—particularly within the first 3 months—face a significantly higher risk of developing central precocious puberty, according to research presented at the first Joint Congress between the European Society of Paediatric Endocrinology and the European Society of Endocrinology in Copenhagen.
The nationwide cohort study of 322,731 South Korean children found that girls who received antibiotics before 3 months of age had a 33% increased risk of early puberty, with the risk climbing to 40% for those exposed before 14 days of age. The researchers noted that 90.4% of children in the study received antibiotics before their first birthday.
Additionally, exposure to multiple antibiotic classes further elevated risk, with girls who used five or more antibiotic classes showing a 22% higher central precocious puberty (CPP) risk compared to those who used two or fewer classes. No similar association was observed in boys.
"This population-based study is one of the first to explore this association between early-life antibiotic use, including the timing, frequency and number of classes, and in such a large national cohort of children," said study investigatgor Yunsoo Choe, MD, of Hanyang University Guri Hospital, South Korea.
The findings build on previous research linking early-life factors affecting gut microbiome to pubertal development. Dr. Choe's team previously found that exclusive breastfeeding was associated with lower CPP risk, supporting the hypothesis that early-life influences on the gut microbiome or endocrine-metabolic pathways may affect pubertal timing.
For the current study, researchers followed children until girls turned 9 and boys turned 10, with CPP diagnosis based on ICD-10 coding and gonadotropin-releasing hormone agonist prescriptions. CPP is defined as the onset of secondary sexual characteristics before age 8 in girls and before age 9 in boys. The investigation used a multivariable Cox proportional hazards model to estimate adjusted hazard ratios for CPP according to timing of first antibiotic prescription and the number of antibiotic classes used.
The results revealed a dose-dependent relationship between antibiotic exposure timing and CPP risk in girls. Compared with those prescribed antibiotics after their first year, girls receiving antibiotics showed increased hazard ratios: before 3 months, at 3 to 6 months, at 6 to 9 months, and at 9 to12 months.
"Our results may encourage doctors and parents to consider the long-term effects of antibiotics when making treatment decisions for young children," said Dr. Choe. "Our study adds to growing concerns about how antibiotics given in infancy could affect children's long-term development—possibly by altering the gut microbiome or hormonal balance—but the reasons behind it are still unclear."
The researchers plan to further explore how early antibiotic use affects pubertal development and whether repeated or long-term exposure during childhood influences other aspects of growth, metabolism, or endocrine health.
Source: EPSE - ESE Press Release
