Phthalate esters are used widely as plasticizers for polyvinylchloride (PVC) formulations in several applications, including medical devices, toys, food wraps, and building products, to impart flexibility to an otherwise rigid PVC. Di-(2-ethylhexyl)phthalate (DEHP) is the most commonly used plasticizer. Because DEHP does not bind with the plastic, it leaches with time and use from vinyl products, thus becoming a ubiquitous environmental contaminant (Bauer and Herrmann 1997;Bradbury 1996;Giam et al. 1978;Griffiths et al. 1985;Mayer et al. 1972;Mes et al. 1974;Øie et al. 1997;Sharman et al. 1994). In particular, leaching of DEHP from PVC medical devices and deposits in tissue have been well documented (Latini 2000;Tickner et al. 2001). Because the DEHP action depends on dose, time, and age (Latini 2000) and because DEHP effects are influenced by the stage of development at exposure among animals (Akingbemi et al. 2001), the DEHP-related exposure risk is potentially higher for the developing fetus and newborn, particularly preterm. Recently, our preliminary findings indicated that the exposure to these environmental contaminants begins during intrauterine life, that these chemicals are able to cross the placental barrier, and that fetal exposure is closely related to maternal exposure (Latini et al. 2003). The aim of this study was to measure concentrations of DEHP and/or its main metabolite, mono-(2-ethylhexyl)phthalate (MEHP), in a larger population of human neonates and to evaluate possible biologic effects from prenatal exposure to DEHP and/or MEHP.
Patients and MethodsSubjects. Cord blood samples were collected from 84 consecutive newborns (82 singletons, two twins), born at the general-practice Brindisi Hospital, with the following characteristics: 39 male, 45 female; maternal age at delivery, 29.5 ± 5.1 years (range = 18-42); vaginal delivery, n = 65 (77.4%); gestational age, 38.4 ± 2.2 weeks (range = 27-42); birth weight, 3,220 ± 680 g, (range = 1,150-4,350); 1-min Apgar score, 7.9 ± 0.9; 5-min Apgar score, 8.8 ± 0.5. Eleven of 84 infants were preterm; only three had very low birth weight. Moreover, four infants who were small for gestational age (SGA) were present in our population. None of the examined infants was born after in vitro fertilization pregnancy. The study was approved by the ethics committee of the Brindisi Hospital (Brindisi, Italy), and written informed consent from the parents was obtained. Blood specimens were immediately centrifuged (3,500 × g, 7 min), and serum was stored at -20°C until assay. To avoid any contamination from plasticizers in lab equipment, the serum sample collection, preservation, and treatment were performed only with glass devices. The concentrations of DEHP and MEHP were determined by highperformance liquid chromatography, at the Department of Chemistry of the University of L'Aquila, an institution certified in agreement with the International Organization for Standardization 9001 quality system, as described previously .Data analysis. Data are expressed as mean ± SD...