impact of gestational nicotine exposure on intrauterine and fetal infection in a rodent model we investigated the interaction between prenatal nicotine exposure and intrauterine infection using established rat models beginning at gestation day gd 6 dams were continuously infused with either saline or 6 mgkgday nicotine nic at gd 14 dams received either sterile broth or 105 colonyforming units mycoplasma pulmonis mp resulting in four treatment groups control 4 dams 33 fetal units mp only 5 dams 55 fetal units nic only 5 dams 61 fetal units and nic mp 7 dams 82 fetal units at gd 18 nicotine exposure significantly increased p 002 the percentage of amniotic fluids and fetuses infected by mp but did not impact colonization rates of maternal sites nicotine exposure significantly reduced the numbers of mp in the placenta required for high microbial loads 104 colorchanging units in the amniotic fluid p 001 fetal inflammatory response lesions were most extensive in the nic only and nic mp groups p 00001 control and mp only placentas were interleukin il10dominant consistent with an m2th2 environment placentas exposed to nicotine shifted to a neutral environment with equivalent levels of interferon gamma ifng and il10 both il6 and tumor necrosis factor tnf levels in amniotic fluid were highly elevated when both nicotine and infection were present our study suggests that prenatal exposure to nicotine increases the risk for intrauterine infection lowers the infectious dose required to breach the placental barrier and infect the amniotic fluid and fetus and alters the pathology and inflammatory profile associated with maternal and fetal sites