Fertility problem increases with age. According to a latest research, women with O blood type are nearly twice as likely to experience conception difficulties as they age. The study conducted by researchers from Yale University and the Albert Einstein College of Medicine, New York, will be presented at the 66th annual meeting of the American Society for Reproductive Medicine, in Denver, Colorado.
A female child is born with around two million eggs. Her egg reserve dwindles with age. When she attains puberty, around 400,000 eggs are present in her ovary. By the time she reaches her 40th birthday, she is left with few hundreds of healthy eggs. In the American study, researchers have found that the blood type of a woman determines her ‘ovarian reserve’.
The researchers compared the blood type and the Follicle Stimulating Hormone of 563 women undergoing fertility treatment. The Follicle Stimulating Hormone is secreted by the pituitary gland. It regulates the menstrual cycle and stimulates production of matured eggs in the ovaries. The level of this hormone usually peaks before ovulation.
As a woman nears menopause, her ovarian reserve falls. This is accompanied by reduction in estrogen secretion. The brain responds to the drop in the estrogen level by stimulating production of the Follicle Stimulating Hormone, to encourage development of the follicles. The lower the ovarian reserve, the higher will be the level of the Follicle Stimulating Hormone. The FSH level remains at a higher level even after menopause. Fertility problems usually occurs in women with FSH above 10, whereas FSH level above 20 is a sign of infertility in women.
While studying the FSH levels of women, less than 45 years of age, researchers found that the level of this hormone was especially high in women with O type blood. Women with O blood type had a two-fold risk of being diagnosed with FSH level above 10. On the other hand, the A blood group gene seems to slow down reduction in the ovarian reserve in women with A and AB blood groups.
According to reproductive health experts, this study would help women with O blood groups recognize the problems associated with late pregnancy.