Abstract： Objective To investigate the pulmonary morphologic changes and pulmonary surfactant protein A (SP-A) mRNA expression in fetal rats with maternal intrahepatic cholestasis of pregnancy (ICP).Methods Animal models of intrahepatic cholestasis of pregnancy were induced by 17-α-ethinylestradiol and progesterone.Histopathologic examination of the fetal lungs was performed under light and electronic microscopes.The expression of SP-A mRNA in the fetal lungs was measured by reverse transcription-polymerase chain reaction technique.Results (1) Compared with the control group,histopathologic examination showed that fetal pulmonary tissues had dilated and congested interstitial lung capillaries,thickened alveolar septum,mild focal inflammatory exudation and focal hemorrhage in alveolus.Furthermore,reduced microvilli,mitochondrion vacuolization,cytoplasm disintegration and increased lamellar body evacuation were observed in alveolar epithelial cell II in ICP group under light and electronic microscopes.(2) Expression of SP-A mRNA in fetal lungs of ICP group (0.71 + 0.10) was significantly lower than that in control group (1.00±0.27),t=3.093,P＜0.05.Conclusions Hyperbileacidemia in ICP maternal rat might lead to pathological changes in fetal pulmonary tissues.Low expression of SP-A mRNA might contribute to lesions of fetal lung with ICP.