Complement factors in fetal and maternal blood and amniotic fluid during the second trimester of normal pregnancy.
Complement factors (C3, C4, C5; Factors B, H and I) were measured in maternal and fetal serum and amniotic fluid obtained from 55 women with singleton pregnancy undergoing diagnostic fetoscopy at 15 to 28 weeks gestation. Maternal serum levels were consistently 10 times higher than fetal levels which in turn were 10 times higher than levels in amniotic fluid. Spearman rank correlation analysis at weeks 20 to 22 (n = 20) revealed a statistically significant correlation between maternal and fetal levels of C3 and Factors B and I, and between maternal and amniotic fluid levels of Factors B and I. A significant increase in fetal levels of C3, C4 and Factor H, and in amniotic fluid levels of C3 and Factor B was seen in relation to advancing gestational age. These differences were not seen in maternal serum during the short interval of pregnancy studied. These data confirm earlier assumptions of fetal synthesis of complement factors, and provide normal reference ranges of complement factors in fetal blood and amniotic fluid.
Stabile
I
I
Academic Unit of Obstetrics and Gynaecology, London Hospital Medical College, UK.
Nicolaides
K H
KH
Bach
A
A
Teisner
B
B
Rodeck
C
C
Westergaard
J G
JG
Grudzinskas
J G
JG
D000653:Amniotic Fluid / Q000032:analysis*; D003176:Complement C3 / Q000032:analysis; D003180:Complement C3b Inactivator Proteins / Q000032:analysis; D003181:Complement C4 / Q000032:analysis; D003182:Complement C5 / Q000032:analysis; D011415:Complement Factor B / Q000032:analysis; D017242:Complement Factor H; D017244:Complement Factor I; D003165:Complement System Proteins / Q000032:analysis*; D003430:Cross-Sectional Studies; D005260:Female; D005312:Fetal Blood / Q000032:analysis*; D006801:Humans; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D012697:Serine Endopeptidases / Q000032:analysis
C493495:CFH protein, human; D003176:Complement C3; D003180:Complement C3b Inactivator Proteins; D003181:Complement C4; D003182:Complement C5; D017242:Complement Factor H; D003165:Complement System Proteins; D012697:Serine Endopeptidases; D017244:Complement Factor I; D011415:Complement Factor B