title: Circulating human pregnancy zone protein and oestriol in twin pregnancies.
mesh_terms: D004964:Estriol / Q000097:blood*; D005260:Female; D006801:Humans; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000032:analysis*; D011272:Pregnancy, Multiple; D014427:Twins
chemical_list: D011257:Pregnancy Proteins; D004964:Estriol