The Northwestern University multihospital twin study: III. Obstetric characteristics and outcome.
D001034:Apgar Score; D001724:Birth Weight; D036861:Delivery, Obstetric; D005260:Female; D005865:Gestational Age; D006801:Humans; D007746:Labor Presentation; D008297:Male; D011247:Pregnancy; D011272:Pregnancy, Multiple; D013997:Time Factors; D014427:Twins