A shift from a male to a female majority in newborns with the increasing age of grand grand multiparous women.
Authors: Juntunen, K S; Kvist, A P; Kauppila, A J
Source: Human Reproduction, Volume 12, Number 10, October 1997 , pp. 2321-2323(3)
Publisher: Oxford University Press
Abstract:In this longitudinal study, we investigated the relationship of birth order and the age of mother and father to the gender of 1795 newborns (mean +/- SD 12.5 +/- 1.6 per mother) of 143 grand grand multiparous (i.e women who have had >10 deliveries). The frequency of boys was 52.2% in the group of 1st to 9th paras and 46.2% in the group of 10th to 20th paras (P = 0.022). Mothers aged > or =35 years had 7.0% more female than male newborns (P = 0.024). The respective figure for fathers was 5.6% (P = 0.023). The interpregnancy interval evaluated for 96 mothers with 1091 deliveries had no correlation with the gender of the infants. In the stepwise logistic regression analysis, the age of the mothers remained the only significant independent factor for the shift from a male to a female majority in the newborns (P = 0.0389). The present data thus indicate that the age of the mother is the factor which explains why grand grand multiparous women deliver more girls than boys.
Document Type: Journal article
Publication date: 1997-10-01
- Human Reproduction features full-length, peer-reviewed papers reporting original research, clinical case histories, as well as opinions and debates on topical issues. Papers published cover the scientific and medical aspects of reproductive physiology and pathology, endocrinology, andrology, gonad function, gametogenesis, fertilization, embryo development, implantation, pregnancy, genetics, genetic diagnosis, oncology, infectious disease, surgery, contraception, infertility treatment, psychology, ethics and social issues. The highest scientific and editorial standard is maintained throughout the journal along with a rapid rate of publication.