title: Twinning rates by residence in Denmark 1978 to 1982.
abstract: It has been suggested in the literature that twinning rates are reduced by psychosocial stress associated with urban life. No support for this hypothesis was found in a study based upon the 5,762 twins and 280,158 singletons that were born in Denmark in the period 1978 to 1982.
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D003718:Denmark; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D011247:Pregnancy; D011272:Pregnancy, Multiple; D012424:Rural Population; D014427:Twins; D014505:Urban Population