Evolutionary and reproductive biologists as well as demographers have always thought that sex selection of the offspring is much more than a matter of chance — that is, whether a sperm bearing a male sex chromosome or one bearing a female sex chromosome reaches the ovum first.
The controversial theory, put forward by Valerie Grant and her colleagues at the University of Auckland, New Zealand says that the emotional status of the mother at the time of conception may have a role to play. If a woman is stressed out at the time of conception, the chances of her delivering a male baby are relatively high. This would also be true if she is of a dominating nature, the scientists point out.
They used cow embryos for the latest study, reached this conclusion by measuring the levels of testosterone (the male sex hormone) in the fluid (or follicular fluid) that surrounds the ovum and correlating it with the sex of the offspring.
" In males testosterone is produced by the testes, in females it is generated in the peripheral tissues that are controlled by the adrenal glands. When stressed, the testes put a brake on testosterone production, whereas the adrenal gland — associated with the production of the stress hormone, cortisol — releases more testosterone as a reaction to stress", says Grant.
A dominant section of reproductive biologists, however, is not convinced. "Whatever they have shown has been done under laboratory conditions. In nature, it doesn't work that way," says Atmaram Bandivdekar, a scientist with the National Institute for Research in Reproductive Health, Mumbai.
Reproductive biologists may take years to resolve their differences relating to the sex selection of embryos.
dis is pure rubbish