Effect of prenatal nicotine exposure on heart development

Abstract

Despite the increasing knowledge of the adverse effects nicotine and cigarette smoking on the unborn fetus many women continue smoking during pregnancy. Previous studies have demonstrated that nicotine abuse retards maternal weight gain and causes a reduction in fetal growth. The effect of nicotine on fetal heart development is unknown. The present study tested the hypothesis that fetal heart weight is affected by maternal nicotine use. Nine pregnant Sprauge-Dawley rats were treated with either saline (control, C) or nicotine (2.1 mg/day, N) using Osmotic MiniPumps from day-4 to day-21 of gestation. The body weight and food intake of pregnant rats were weighed daily. On day 21 the rats were terminated and the fetuses were removed and weighed. In addition the hearts were isolated and weighed. The results obtained showed a significant difference between the control and nicotine-treated rats in the maternal food intake, which coordinated with the maternal body weight gain. No significant differences were found in the litter number, however, fetal body weight did show a significant decrease (C = 4.06 ± 0.04 g, N = 3.87 ± 0.06 g; p < 0.05). No significant difference was seen in fetal heart weight or heart to body weight ratio. The results suggest that nicotine affects maternal food intake and maternal body weight gain in the first few days of pregnancy as well as fetal body weight; however, there is no significant effect on fetal heart weight.