[Why twins are born].
D004200:Diseases in Twins; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D011247:Pregnancy; D011272:Pregnancy, Multiple; D014427:Twins; D014429:Twins, Dizygotic; D014430:Twins, Monozygotic
Pochemu rozhdaiutsia bliznetsy.