title: Prenatal diagnosis in twin pregnancies.
mesh_terms: D000110:Acetylcholinesterase / Q000032:analysis; D000328:Adult; D000649:Amniocentesis; D002869:Chromosome Aberrations / Q000235:genetics*; D025063:Chromosome Disorders; D004200:Diseases in Twins; D004314:Down Syndrome / Q000235:genetics; D005260:Female; D005817:Genetic Counseling; D006801:Humans; D007231:Infant, Newborn; D007621:Karyotyping; D009136:Muscular Dystrophies / Q000235:genetics; D011247:Pregnancy; D011272:Pregnancy, Multiple; D011296:Prenatal Diagnosis; D012307:Risk Factors; D014463:Ultrasonography; D000509:alpha-Fetoproteins / Q000032:analysis
chemical_list: D000509:alpha-Fetoproteins; D000110:Acetylcholinesterase