## Abstract The prenatal environment influences offspring traits in a variety of ways and in a wide range of taxa. For example, maternal allocation of steroids to the eggs influences offspring traits in birds, and in some mammals the intrauterine position influences morphological, behavioural, and
Determination of prenatal sex ratio in man
โ Scribed by Masaharu Yamamoto; Takashi Ito; Gen-ichi Watanabe
- Book ID
- 104777542
- Publisher
- Springer
- Year
- 1977
- Tongue
- English
- Weight
- 301 KB
- Volume
- 36
- Category
- Article
- ISSN
- 0340-6717
No coin nor oath required. For personal study only.
โฆ Synopsis
The sex of a conceptus at the early embryonic state was diagnosed in 1000 induced abortions. Specimens were obtained from women who terminated their pregnancies within 12 menstrual weeks on socio-economic indications. By making use of the triple checking procedures, such as the karyotypic analysis of Giemsa-stained slides, the fluorescent Y chromosome analysis and the Y-body test in interphase nuclei, the sex ratio was determined as 106.6 (516 males/484 females). The sex distribution in the chromosomally normal embryos was 481 in males to 448 in females; that gave the ratio of 107.4. A slight excess of males was already present at his stage of pregnancy. When the ratios were calculated in relation to the maternal age, the lower sex ratio was noted for embryos born to mothers over 30 years. Taking a Y-bearing embryo as male, the ratio in 71 chromosomally aberrant embryos was 97.2 (35 males/36 females). The sex ratio in the cases of chromosome abnormalities was not statistically different from that of thenormal embryos.
๐ SIMILAR VOLUMES
Variation in intrauterine exposure to hormones associated with variation in the sex of litter mates has well-established and far-reaching effects on sexual development in some mammals. Research on this phenomenon in reptiles is scant, but suggests that lizards may follow the mammalian model whereas