Developmental and Maternal Toxicity in Progeny of Rat Mothers Exposed to Methyl Mercury During Gestation

Methylmercury (MeHg) is a pervasive and enduring environmental pollutant present in various food sources, predominantly seafood. It is particularly neurotoxic to developing nervous systems. This study investigates the effects of prenatal MeHg exposure on early developmental milestones and neurobehavioral functions in rats, focusing on different gestational periods. Pregnant rats were exposed to MeHg (0.5, 1.0, and 1.5 mg/kg/day) from gestation day 8 until parturition. Findings revealed no maternal toxicity signs across treatment groups. However, significant reductions in maternal weight gain were noted at higher doses. While absorption or early deliveries were absent, there were increased mortality rates in pups, particularly at the 1.5 mg/kg/day exposure level. This dose also led to reduced numbers of viable litters and increased post-implantation loss, suggesting heightened teratogenic risks. These results underscore the potential dangers of gestational MeHg exposure, emphasizing the need for caution regarding its use during pregnancy.