The activity of ALP and PALP activity gradually increased after 15th weeks, rose suddenly after 30th weeks, the great peak at 40 weeks, however decreased sharply after 41th. Those changes were result from by PALP in urine.

• 当进入妊娠中期 (15周 )后 ,酶活性开始平稳上升 ,进入晚期 (30周后 ) ,酶活力突跃上升至 4 0周达高峰 ,4 1周急剧下降 ,产后恢复正常酶活性水平 ,这些变化主要由Palp的升降导致。