title: Fertility in twins.
abstract: From the 474 twins born in 1950 in 100 Flemish cities and towns in Belgium, 85% reached the age of 20 yr, against 37% in Austria a hundred years ago. More female than male twins are married (P = 0.03), in particular nonidentical female twins (P = 0.02). Fertility seems to be lower in male, especially male-male twins (P less than 0.03), and most strikingly so in identical male twins (P = 0.05). There seems to be no influence of premature birth or low birthweight.
authors.affiliation: Department of Internal Medicine, University Hospitals, Leuven, Belgium.
authors.forename: O
authors.initials: O
authors.lastname: Steeno
authors.forename: R
authors.initials: R
authors.lastname: Vlietinck
mesh_terms: D001724:Birth Weight; D005260:Female; D005298:Fertility; D006801:Humans; D007223:Infant; D008297:Male; D011795:Surveys and Questionnaires; D014427:Twins