Maternal Exposure to Persistent Organic Pollutants Linked to Urologic Conditions in Boys

Higher incidences of congenital anomalies, including cryptorchidism (undescended testicles) and hypospadias, were found in boys whose mothers had higher serum levels of certain organochlorine compounds, researchers say. Two separate studies presented today during the Annual Scientific Meeting of the American Urological Association (AUA) in Orlando confirmed existing hypotheses that maternal exposure to endocrine-disrupting chemicals – including total polychlorinated biphenyls (PCBs, such as Arochlor) and organochlorinated pesticides (such as dichlorodiphenyl-trichloroethane, or DDT) may contribute to an increased incidence of these conditions.

The data was presented to the media on Sunday, May 18, 2008, during press conferences starting at 8:00 a.m.

Mothers with high levels of organochlorine compounds in their bodies are at a greater risk of bearing sons with undescended testicles (cryptorchidism). In a study (abstract #276) of 40 boys undergoing surgical treatment for the condition, researchers from New York and Michigan analyzed PCB serum levels from both the patient and the mother and compared the readings to residual PCB levels in the patients’ fatty tissue samples (taken at surgery). Patients ranged from eight to 18 months of age at the time of treatment.

Researchers’ analysis of the amount of OCC residue in the samples revealed that serum PCB levels reflect the fatty burden of OCC residues in the boys, and OCC concentration in maternal serum samples correlated with the son’s serum levels. Aggregate PCB levels and maternal levels of individual PCB congeners were significantly higher in boys with undescended testicles than in mothers of boys without the anomaly.

Researchers from Michigan and Atlanta presented similar findings (abstract #277) on congenital anomalies and chemical exposure. Using data from the Michigan Long-Term PBB Cohort, researchers examined individuals exposed to polybrominated biphenyl (PBB) during 1974-1974, including sons of mothers with known serum PBB levels, to determine whether in-utero exposure to PBB put male neonates at a greater risk for genitourinary (GU) or reproductive conditions. Self-reported data on varicocele, cryptorchidism, hypospadias and other GU and reproductive conditions was compared to estimated maternal PBB levels at the time of conception.

Of the sons whose mothers had measurable PBB levels at the time of conception, 35 reported GU conditions, including hernias (13), hydroceles (10), undescended testicles (9), hypospadias (5), phimosis (2) and varicocele (1). Sons whose mothers had PBB levels greater than 5 parts per billion were more likely to report these conditions than those whose mothers had lower levels. Maternal PBB levels were not found to have an impact on birth weight or estimated gestational age. 12.2 percent of boys with maternal serum levels greater than 5 were more likely to report GU conditions, compared to 5.5 percent of boys with lower maternal PBB levels.