[The dynamics and its clinical significance of complement system, especially alternative pathway related to normal human pregnancy, delivery, puerperium and fetus (author's transl)].

The author studied human complement system, especially alternative pathway as a primitive biological defense system, in maternal serum during normal pregnancy, delivery and puerperium. The results obtained were as follows. 1. The mean value of hemolytic activity of alternative pathway (AlCH50) in healthy women was 18.3 +/- 1.1. This value was increased gradually in progress of gestational stages up to 26.6 +/- 2.3 of the average in the last trimester. Stochastically, significant differences about this value was noted between in the first trimester and in the last. This AlCH50 is decreased temporarily at delivery, and it was increased again rapidly, then went down to normal range about one month after delivery. 2. The average of immunochemical C3PA by SRID method during pregnancy was 22.5 +/- 0.4 mg/dl. It was significantly higher than the average 18.1 +/- 0.4 mg/dl of 59 healthy women. C3PA was noted to remain high level constantly during pregnancy. This C3PA level after delivery was observed to take a similar pattern as AlCH50. 3. beta 1C/1A globulin (C3) in 19 healthy women was 60.7 +/- 2.1 mg/dl. This C3 was also increased gradually during pregnancy up to maximum level of 87.5 +/- 2.8 mg/dl at the 3rd trimester. 4. Classical pathway (CH50, C4 and Cl INA) and fetal complement level were investigated at the same time and discussed here.