The median age for receiving a Ph.D. is 34, so by the time a woman is up for tenure, she is 40 and confronting higher infertility rates.

They say the changes may partly explain rising infertility rates in Western nations, as well as other hormonal problems linked to the endocrine system.

Other factors determining age of first child birth include infertility rates, when women meet their partners, and the age of marriage.

Criticism of surrogate contracts and other reproductive technologies is on the rise in the United States and in other nations even as infertility rates rise and the demand for surrogate arrangements increases.

The reduction with unilateral cryptorchidism is subtle, with a reported infertility rate of about 10%, compared with about 6% reported by the same study for the general population of adult men.

As women have delayed starting their families, infertility rates have soared.

Living disproportionately high on the food chain, at levels at which toxic substances become concentrated, they are at more rather than less risk of reproductive impairment due to ingestion of or exposure to toxic materials, possibly contributing to their higher infertility rates and the increasing frequency with which they require medical assistance in conceiving.

He had also established that the infertility rate of triffid seeds was something like 95 per cent.

Polycystic ovarian disease (PCOD) : PCOD increases the infertility rate in females.

This leads to a delicate compromise between the two, and has been suggested as one possible cause for the relatively high infertility rates seen in mammalian species.