Prenatal Nicotine Exposure Affects Cardiovascular Function and Growth of the Developing Fetus

Aim: Effects of nicotine on fetal hemodynamics are not well known, especially in the first trimester fetus. We investigated the acute and chronic effects of nicotine on hemodynamics in pregnant mice and their fetuses using ultrasound. Postnatal health status including growth and hemodynamics was also examined.

Methods: To investigate the acute effects of nicotine on fetal hemodynamics, we injected nicotine 0.2 mg/kg subcutaneously into pregnant mice on gestational days (GD) 9.5, 11.5 and 13.5 and compared with saline-injected group. To determine the chronic effects of nicotine on fetal hemodynamics, we administered nicotine in drinking water (0.1 mg/mL) to pregnant mice from GD 6.5 until they gave birth and compared hemodynamics with water-administered mice.

Results: Regarding the acute effects of nicotine, we found no intergroup difference in maternal hemodynamics; however, fetal blood flow through the dorsal aorta, carotid artery and umbilical artery tended to decrease, particularly on GD 11.5. Regarding the chronic effects of nicotine, we observed no intergroup difference in maternal body weight changes and hemodynamics; however, blood flow to all fetal organs tended to be lower in the nicotine water group than in the water group with significant difference on GD 13.5. The offspring of the nicotine water group had significantly low birth weights and continued to have low body weight until 9 weeks of age. In addition, these offspring developed postnatal cardiac hypertrophy.

Conclusion: Nicotine adversely affects fetal hemodynamics acutely and chronically in early pregnancy, potentially leading to fetal tissue hypoxia, intrauterine growth restriction and adverse postnatal health effects.

Keywords: fetus; hemodynamics; neonate; nicotine.