[Study on fetal hypoxia in intrahepatic cholestasis of pregnancy]

To investigate the mechanism and the related factors of fetal hypoxia in intrahepatic cholestasis of pregnancy (ICP).

Cord blood total bile acids(TBA), hypoxanthine (HX), and endothelin (ET) concentrations were measured in 30 newborns of mothers with ICP and 30 infants of normal pregnancy as control, and the cord nucleated red blood cells (NRBC) were counted as well.

(1) The mean cord arterious plasma HX concentration in hypoxic fetuses of mothers with ICP was significantly higher than those in fetuses without hypoxia of mothers with ICP and fetuses of normal pregnancy (18.68 +/- 15.73) mumol/L, (6.87 +/- 2.82) mumol/L, (6.81 +/- 2.83) mumol/L (P < 0.01). However, there were no differences of the cord NRBC value (4.20 +/- 2.49)/100 white blood cell, (3.40 +/- 2.26)/100 white blood cell, (3.50 +/- 1.74)/100 white blood cell; P > 0.05) and the mean cord arterious plasma ET concentration (72.44 +/- 12.23) ng/L, (70.16 +/- 26.61) ng/L, (67.27 +/- 43.56) ng/L, P = 0.910) among the three groups. (2) In ICP group, the mean cord serum TBA concentration in hypoxic fetuses was significantly higher than that in fetuses without hypoxia, while the latter was higher than that in control group (23.77 +/- 11.82) mumol/L, (14.86 +/- 5.46) mumol/L, (9.28 +/- 4.39) mumol/L; (P < 0.01). There was a positive correlation between the cord plasma HX concentrations and TBA concentrations in ICP (r = 0.689, P < 0.01). There was higher prevalence of meconium stained amnionic fluid in ICP group than that in control group (53.3%, 13.3%; P < 0.01). Besides in ICP group the TBA levels of fetuses with meconium staining were significantly higher than those without [(21.44 +/- 9.92) mumol/L, (13.69 +/- 5.74) mumol/L; (P < 0.05)].

The results suggested that fetal hypoxia and stillbirth in ICP may be the result of acute hypoxia. Acute insufficient fetal infusion and oxygenation based on the insufficiency of fetal placental oxygen reserve resulting from the reduction in the size of the intervilous space in ICP may develope at stress such as uterine contraction and meconium passage.