胆红素代谢对人体有重要作用,游离型胆红素可自由穿过脂膜和血脑屏障等,产生细胞毒性而引发新生儿核黄疸.胎儿胆红素代谢与成人不同,胎儿期肝脏尚未发育成熟,其体内只有少量胆红素可经肝脏转化为无毒的结合型胆红素,大部分是非结合型胆红素以胆红素-白蛋白复合物的形式溶于血浆中,通过胎盘上的胆红素转运载体运送至母体代谢.当胎儿体内胆红素浓度过高或白蛋白浓度降低等病理情况下,胆红素可从白蛋白结合位点上解离成为游离型胆红素,其可对胎儿产生神经毒性作用,造成胎儿不良结局.%Bilirubin metabolism plays an important role for the human,free bilirubin can pass through cell membranes, blood-brain barrier and lipid membranes freely, resulting in cell toxicity and neonatal kernicterus.Fetal bilirubin metabolism is different from the adults'. Because of the immaturity of fetal liver function, only a small amount of fetal bilirubin can be transformed into non-toxic conjugated bilirubin via fetal liver, while most of the unconjugated bilirubin dissolved in the plasma in the form of bilirubin-albumin complex is transferred to mother to be metabolized by bilirubin carriers in the placenta. In certain pathological conditions, such as high concentration of bilirubin or low concentration of albumin, bilirubin-albumin complex may be dissociated from albumin binding sites to free bilirubin, which can result in neurotoxic effects on fetus, causing fetal adverse outcomes.
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