Endocrine disruptors in the maternal and fetal compartments

Abstract

SUSAN LASHLEY, ANTONIA CALAFAT, DANA BARR, THOMAS LEDOUX, PAROMITA HORE, MARIAN LAKE, MARK ROBSON, JOHN SMULIAN, UMDNJRobert Wood Johnson Medical School/Robert Wood Johnson University Hospital, Obstetrics, Gynecology and Reproductive Sciences, New Brunswick, New Jersey, Centers for Disease Control and Prevention (CDC), Division of Laboratory Sciences, National Center for Environmental Health, Atlanta, Georgia, New Jersey Department of Environmental Protection, Risk Assessment & Toxicology Section, Division of Science and Research, Trenton, New Jersey, University of Medicine and Dentistry of New Jersey, School of Public Health, Dept. of Environmental & Occupational Health, Piscataway, New Jersey OBJECTIVE: Phthalates (plasticizers) are known endocrine disruptors in the animal kingdom and are associated with developmental toxicities. This study was designed to describe the relationship between levels of phthalate metabolites in human maternal serum and cord serum. STUDY DESIGN: Cord blood and maternal blood were collected from 50 maternal-fetal pairs at the time of elective cesarean section between July 2003May 2004. The collection materials were tested prior to obtaining samples and the collection procedure was designed to minimize the potential for phthalate contamination. The Centers for Disease Control and Prevention analyzed the maternal and fetal sera, using automated solid phase extraction-isotope dilutionhigh performance liquid chromatography-tandem mass spectrometry, for nine metabolites of phthalates. Correlation of phthalates in maternal and fetal sera was assessed based on spearman rank correlation coefficient (r). RESULTS: Phthalate metabolites were detected in 100% of maternal and cord serum samples. However, the frequency of detection for each specific metabolite differed between the two compartments. Seven of the nine phthalate metabolites were more frequently detected in cord serum than maternal serum. For example, mono-2-ethylhexyl phthalate (MEHP) was detected in all of the cord samples but in only 69% of maternal samples (P ! .001). The concentration of MEHP, mono-(2-ethyl-5-hydroxyhexyl) phthalate, and mono-(2-ethyl-5-oxohexyl) phthalate were higher in cord serum then the maternal serum. When metabolites were present in both compartments, a correlation between levels in maternal and fetal sera was found for mono-n-butyl phthalate P = .03 (r =.54), mono-benzyl phthalate P = .04 (r =.40), mono-ethyl phthalate P = .007 (r =.41). CONCLUSION: This study confirms that phthalates metabolites are present in the human fetal compartment. The metabolites levels in cord serum were generally higher than in maternal serum. These results may indicate that the mechanism of fetal clearance of phthalates may predispose to trapping of phthalates in the fetal compartment.