Published online by Cambridge University Press: 01 August 2014
HCS, HCG, and HCG α and β subunits were measured in the serum of women with unifetal or multiple pregnancies. Highly specific radioimmunoassay procedures were used for the determinations.
Serum maternal levels of HCS are greatly increased in multiple pregnancies, sometimes more than could be expected from increased placental weight alone. Serum undissociated HCG is also elevated in multiple pregnancies. The relationship between undissociated HCG and its free circulating α and β subunits is different in multiple and unifetal pregnancies and this difference is discussed.