Kessler Jörg, Rasmussen Svein, Godfrey Keith, Hanson Mark, Kiserud Torvid
Department of Clinical Medicine, University of Bergen, N-5020 Bergen, Norway.
Pediatr Res. 2008 Mar;63(3):315-20. doi: 10.1203/pdr.0b013e318163a1de.
Recent data suggest that umbilical venous perfusion of the fetal liver has an important influence on fetal growth and postnatal liver function, and that maternal factors in late pregnancy modify this circulation. In a longitudinal study of 160 low-risk pregnancies, we determined how umbilical and portal venous blood flows to the fetal liver changed during gestation, and examined the hypothesis that maternal body mass index and pregnancy weight gain influenced fetal liver blood flows. We measured blood flows in the umbilical and portal veins, left portal branch, and ductus venosus using ultrasound. Normalizing for estimated fetal weight, fetal liver total venous blood flow fell from 84 to 57 mL. min(-1). kg(-1) during 21-39 wk of gestation; toward term the portal contribution increased (from 14 to 20%) and the umbilical contribution fell, whereas distribution between the left and right liver lobes was stable, 60%/40%. Greater flow of nutrient-rich umbilical venous blood to the liver was associated with higher birth weight and neonatal ponderal index. Maternal body mass index was not related to fetal liver blood flows, but low pregnancy weight gain strongly influenced flow distribution between the right and left liver lobes, sparing the left lobe and increasing the difference between lobes by 16%.
近期数据表明，经脐静脉向胎儿肝脏灌注对胎儿生长及出生后肝功能有重要影响，且妊娠晚期的母体因素会改变这种循环。在一项针对160例低风险妊娠的纵向研究中，我们确定了妊娠期间经脐静脉和门静脉流向胎儿肝脏的血流量如何变化，并检验了母体体重指数和孕期体重增加会影响胎儿肝脏血流量这一假设。我们使用超声测量了脐静脉、门静脉、门静脉左支和静脉导管中的血流量。以估计胎儿体重进行标准化后，胎儿肝脏总静脉血流量在妊娠21至39周期间从84降至57 mL·min⁻¹·kg⁻¹；接近足月时，门静脉的供血比例增加（从14%增至20%），脐静脉供血比例下降，而左右肝叶之间的血流分布稳定，为60%/40%。经脐静脉向肝脏输送的富含营养的血液流量增加与出生体重增加及新生儿 ponderal 指数升高相关。母体体重指数与胎儿肝脏血流量无关，但孕期体重增加过少会强烈影响左右肝叶之间的血流分布，使左叶血流量减少，两叶之间的差异增加16%。
