title: The role of Xg a blood group incompatibility in fetal loss--twin study.
mesh_terms: D001787:Blood Group Incompatibility; D005260:Female; D005313:Fetal Death; D008040:Genetic Linkage; D006801:Humans; D008297:Male; D011247:Pregnancy; D012730:Sex Chromosomes; D012744:Sex Ratio; D014427:Twins