Spontaneous preterm labour and delivery at under 34 weeks' gestation.
D001946:Breech Presentation; D036861:Delivery, Obstetric; D005260:Female; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D007234:Infant, Premature; D007746:Labor Presentation; D011247:Pregnancy