Fetal exposure to phthalates and body mass index from infancy to adolescence. The Generation R study

Area of Science:

• Environmental Health
• Pediatric Endocrinology
• Toxicology

Background:

• Prenatal exposure to endocrine-disrupting chemicals, such as phthalates, is a growing public health concern.
• Childhood obesity is a complex condition with potential developmental origins.
• Previous research often assessed body mass index (BMI) at single time points, potentially missing crucial developmental trajectories.

Purpose of the Study:

• To investigate the association between prenatal phthalate exposure and longitudinal body mass index (BMI) development from infancy through adolescence.
• To determine if specific phthalate metabolites or exposure timing during pregnancy influence BMI trajectories.

Main Methods:

• A population-based cohort study included 1,379 mother-child pairs.
• Maternal urine samples were collected during the first, second, and third trimesters to measure phthalate concentrations.
• Longitudinal BMI standard deviation scores (SDS) were calculated from 6 months to 13 years of age.
• Linear mixed-effects models were used to analyze the association between prenatal phthalate exposure and repeated BMI measures.

Main Results:

• Higher first-trimester exposure to high-molecular-weight phthalates and di-2-ethylhexylphthalate (DEHP) was associated with lower BMI at 6 months.
• Conversely, higher first-trimester exposure to phthalic acid and low-molecular-weight phthalates was linked to increased BMI at 13 years.
• No significant associations were found for phthalate exposure during the second or third trimesters with BMI outcomes.

Conclusions:

• Prenatal phthalate exposure may have differential effects on BMI development across childhood.
• Early pregnancy exposure to certain phthalates is associated with lower early-life BMI but higher later-childhood BMI.
• These findings highlight the potential role of phthalates in the developmental trajectory of childhood obesity.