Dr. Maisonet Co-Authors Article on Fetal Exposure to Organochlorine Pesticides
Dr. Mildred Maisonet, an Assistant Professor in the Department of Biostatistics and Epidemiology, has co-authored a publication on the long-term consequences of prenatal environmental exposures. The article in Environment International is entitled “In utero exposure to organochlorine pesticides and early menarche in the Avon Longitudinal Study of Parents and Children.”
Several organochlorine pesticides have been banned or restricted in most countries for decades because of their persistence in the environment and their association with adverse effects in humans and wildlife. However, they are still in use in some developing countries, mainly to control vector-borne diseases. Human exposure to organochlorine pesticides occurs primarily through diet, particularly consumption of fatty foods such as meat, fish, and dairy products. Organochlorine pesticides can be transferred to the developing fetus through the placenta and to newborns through breast milk.
Early menarche, a marker for early puberty, is a risk factor for adverse adult health outcomes including pre- and post-menopausal breast cancer, ovarian cancer, and polycystic ovarian syndrome. “When a baby’s body is undergoing development inside the mother’s womb, a healthy fetal environment is required,” stated Dr. Maisonet. “Chemical substances, such as organochlorine pesticides, are known to cross the placental mother-fetal barrier. Contact of the developing fetus with a chemical may induce changes in its cells and tissues and these changes can eventually become determinants of adult disease.”
The study team utilized a nested case-control design to analyze serum collected during pregnancy from mothers of 218 girls who reported beginning their menstrual cycles (menarche) before 11.5 years of age (cases) and 230 girls who reported menarche at or after 11.5 years of age (controls) for nine organochlorines and metabolites.
The team analyzed the association between in utero organochlorine concentrations and early menarche controlling for mother's age at menarche, or mother's prenatal body mass index. Dr. Maisonet explained, “Our study was the first to examine whether fetal exposure to selected organochlorine pesticides, as determined by their levels in maternal blood during pregnancy, was associated with age at menarche in their daughters – a major reproductive milestone. Our study results did not suggest an adverse effect.” She added, “Reproductive effects of exposure to organochlorine chemicals during other developmental stages have been reported and underscore the need to study whether fetal exposure is also associated with adverse health effects.”
The analysis was led by Dr. Gonza Namulanda, epidemiologist at the United States Centers for Disease Control and Prevention, National Center for Environmental Health.