Action of complement in normal pregnancy and gestosis

: Behaviour of the complement system was studied in normal pregnancy, puerperium and in pre-eclampsia. CH50 showed no variations during normal pregnancy, excepting for first trimester, whereas it increased in puerperium. CVFAH50 increased steadily during all trimesters. C1q, C1s and C1-INH progressively decreased, while C3, C5, C9 and C3PA augmented. All values were clearly raised in puerperium. The decreased values of the early classical pathway components could be attributed to "blocking factors" (antibodies or immune-complexes) which could interfere with cellular immunity at fetoplacental level. The other components probably increase because there is a hormone-stimulated raised synthesis and a high turnover. The data obtained from pre-eclampsia did not reveal significant variations as compared to normal third trimester pregnancy, excepting for CVFAH50 which was reduced. This, however, does not exclude the possibility that there is an immunological pathogenesis of the pre-eclampsia, since activation of the C system is not always detectable in circulation.