Abstract

Lead (Pb) is a heavy metal environmental pollutant and toxicant. The present study investigated dose-related effects of maternal Pb exposure on pregnancy outcome. Wistar albino rats were gavaged with Pb nitrate (4 or 8 mg/kg) or vehicle daily from gestation day 0 until delivery. Length of pregnancy was noted. Number, birth weight and physical characteristics of pups were registered. Neonatal mortality was also recorded between days 1 to 15 post-delivery. Lead treatment significantly (p < 0.05) inhibited maternal body weight gain and caused abortion of pregnancy dose-dependently (4 mg/kg: 67.7%, 8 mg/kg: 100%). Besides, all occurring births in 4 mg/kg Pb-exposed rats were preterm (p = 0.0023) with morphological abnormalities in the head and limbs, and about 33% were still births. Also, average number and birth weight of Pb-exposed rats offspring were significantly (p < 0.0001) lower compared to controls. Furthermore, while body weights of offspring of control rats increased significantly (p < 0.0001) over time, those of Pb-exposed rats decreased significantly (p = 0.0077). Neonatal survival was 0% in Pb treated rats and 100% in control. The results demonstrate that maternal Pb exposure adversely and dose-dependently affects pregnancy outcome.

Key words: Developmental toxicity, gestation, heavy metals, lead, reproductive toxicity, resorption.