title: Hormonal screening for twin pregnancies.
mesh_terms: D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D010928:Placental Lactogen / Q000097:blood; D011247:Pregnancy; D011272:Pregnancy, Multiple; D011296:Prenatal Diagnosis; D014427:Twins; D014463:Ultrasonography
chemical_list: D010928:Placental Lactogen