RESUMEN
It has been suggested that the accumulation of tobacco-derived cadmium (Cd) in the placenta is responsible for the adverse effect of cigarette smoking on infant birthweight. We chose to test this hypothesis; therefore, we studied a population of nonsmoking pregnant women who were exposed to low levels of smelter-derived Cd and a group of nonexposed women. A higher mean placental Cd concentration (p less than .0007) was found in the exposed women (n = 106), compared with those who were not exposed (n = 55); the observed Cd concentrations were comparable to concentrations reported previously for smoking and nonsmoking women, respectively. Least squares multiple regression (controlling for potentially confounding variables) revealed no association between placental Cd and birthweight. It was, therefore, concluded that the effect of smoking on birthweight was not mediated through Cd.
Asunto(s)
Peso al Nacer , Intoxicación por Cadmio/epidemiología , Cadmio/química , Exposición a Riesgos Ambientales , Intoxicación por Plomo/epidemiología , Placenta/química , Adulto , Intoxicación por Cadmio/complicaciones , Intoxicación por Cadmio/diagnóstico , Escolaridad , Etnicidad , Femenino , Sangre Fetal/química , Edad Gestacional , Humanos , Intoxicación por Plomo/sangre , Intoxicación por Plomo/complicaciones , Análisis de los Mínimos Cuadrados , Edad Materna , Metalurgia , Paridad , Embarazo/sangre , Características de la Residencia , Fumar/efectos adversos , Yugoslavia/epidemiologíaRESUMEN
This paper tests the hypothesis that exposure to lead during pregnancy is associated with reduced intrauterine growth and an increase in preterm delivery. The sample comprises women, recruited at mid-pregnancy, residing in Titova Mitrovica, a lead smelter town, or in Pristina, a non-exposed town 25 miles away. Both towns are in the province of Kosovo, Yugoslavia. Mean blood lead concentrations (BPb's) at mid-pregnancy were 0.92 mumol/L (+/- 0.38, N = 401) in the exposed town and 0.27 mumol/L (+/- 0.09, N = 506) in the comparison town. No differences were found between towns for either birthweight or length of gestation. Mean birthweight was 3308 (+/- 566) grams in Titova Mitrovica and 3361 (+/- 525) grams in Pristina. Mean length of gestation was 274 (+/- 18.8) days in Titova Mitrovica and 275 (+/- 15.6) days in Pristina. After adjustment for the effects of potential confounders, no significant relationships were found between maternal BPb measured at mid-pregnancy, at delivery or in the umbilical cord and either birthweight, length of gestation, or preterm delivery (less than 37 weeks). We conclude that exposure to environmental lead does not impair fetal growth or influence length of gestation.