Prenatal Stress as a Modifier of Associations between Phthalate Exposure and Reproductive Development: results from a...

Area of Science:

• Environmental health
• Reproductive toxicology
• Developmental biology

Background:

• Prenatal exposure to phthalates, such as diethylhexyl phthalate (DEHP), is linked to adverse male reproductive tract development, including reduced anogenital distance (AGD).
• Anogenital distance (AGD) serves as a key indicator of prenatal androgen exposure and may be influenced by maternal stress during pregnancy.
• The interactive effects of prenatal phthalate exposure and maternal stress on infant AGD remain largely unexplored.

Purpose of the Study:

• To investigate whether prenatal exposure to stressful life events (SLEs) modifies the association between prenatal phthalate exposure and infant anogenital distance (AGD).

Main Methods:

• Urine samples from 738 pregnant women in the first trimester were analyzed for phthalate metabolites, including diethylhexyl phthalate (DEHP) and its sum (ΣDEHP).
• Maternal reports of stressful life events (SLEs) during pregnancy were collected, categorizing women into 'lower' (0 SLEs) and 'higher' (1+ SLEs) stress groups.
• Adjusted multiple regression models were used to assess the relationship between phthalate concentrations and infant AGD, stratified by infant sex and maternal stress level.

Main Results:

• In male infants of mothers in the lower stress group, higher first-trimester ΣDEHP concentrations were inversely associated with both anoscrotal distance (AGD-AS) and anopenile distance (AGD-AP).
• Conversely, in male infants of mothers in the higher stress group, the associations between ΣDEHP and AGD measures were predominantly positive and not statistically significant.
• No significant associations between prenatal phthalate metabolites and AGD were observed in female infants.

Conclusions:

• The observed inverse association between prenatal phthalate exposure and male genital development (AGD) was evident only in infants born to mothers reporting no prenatal stressful life events.
• These findings indicate a potential interaction between prenatal phthalate exposure and maternal stress, which may collectively influence fetal development of the male reproductive tract.
• Further research is warranted to elucidate the complex interplay between environmental exposures and stress during gestation on reproductive health outcomes.