Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
, 14 (12), 3120-5

Natural Variation in the Human Sex Ratio

Affiliations

Natural Variation in the Human Sex Ratio

R Jacobsen et al. Hum Reprod.

Abstract

Analysis of the effect of multiple birth, birth order, age of parents and the sexes of preceding siblings on the secondary sex ratio was performed for 815 891 children, born in Denmark, 1980-1993. The proportion of males was analysed as a function of multiple birth, birth order, age of parents and the sexes of preceding siblings, using contingency tables, chi(2) tests and logistic regression analysis. The secondary sex ratio decreased with increased number of children per plural birth and with paternal age, whereas no independent effect was observed for maternal age, birth order, the sex of the preceding child, or the combination of sexes of previously born children in the family.

Comment in

Similar articles

See all similar articles

Cited by 35 PubMed Central articles

See all "Cited by" articles

LinkOut - more resources

Feedback