Objective: To investigate the stereological changes of placental lobular villi vessels in patients with intrahepatic cholestasis of pregnancy (ICP).
Methods: Stereological analysis on vessels volume and cross-areas of placental samples taken from 10 normal and 10 ICP patients at 37-40 week pregnancy were performed.
Results: Compared with normal pregnancy, the ICP patients had 29% reduction in the volume of placental lobular villi vessels [(287.81 +/- 69.81) mL vs. (203.63 +/- 41.29) mL]; 21% reduction in the cross-areas [(617119.5 +/- 158422.65) microm2 vs. (485087.6 +/- 104707.63) microm]2; but no change in the numbers [(313.40 +/- 137.51) vs. (365.20 +/- 96.73)] of lobular villi vessels (P>0.05). Similarly, significant decreases in the volume [(131.98 +/- 84.68) mL vs. (55.98 +/- 21.08) mL] and cross-areas [(271809.6 +/- 162354.35) microm2 vs. (127576.2 +/- 54897.44) microm2] of placental lobular villi vessels with smooth muscles in the ICP patients were also found (P<0.05). But the volume [(161.48 +/- 75.80) mL vs. (155.91 +/- 30.52) mL] and cross-areas [(342639.6 +/- 145717.51) microm2 vs. (341849.3 +/- 57043.88) microm2] of placental lobular villi vessels without smooth muscle in the ICP patients remained unchanged (P>0.05). The placental lobular villi vascular volume was negatively correlated (r = -0.413) with the maternal plasma level of total bile acid (TBA) (P>0.05), and positively correlated (r=0.302) with the onset week of ICP (P>0.05). But the correlations were not statistically significant.
Conclusion: Patients with ICP have 29% reduction in placental lobular villi vascular volume, which is mainly a result of reduction of lobular villi vessels with smooth muscles. The placental lobular villi vascular volume is possibly negatively correled with maternal plasma level of TBA, and positively correled with the onset week of ICP.