The ability of a woman to conceive could be influenced by blood type, according to research conducted in the United States.
The study of Albert Einstein Medical School and Yale University involved 560 women with an average age of 35 who were undergoing fertility treatments.
The scientists found that those who belonged to group O had more difficulty becoming pregnant due to lower quality and lower egg count.
The researchers, who presented the study at the conference of the American Society for Reproductive Medicine, held in Denver, Colorado, do not know what to this link.
But stress that the blood group is only a marker of fertility and further studies are needed to confirm the association.
Key Blood
A woman has a set number of eggs, the "ovarian reserve", which is gradually released during her reproductive life.
It is believed that high levels of a hormone, called FSH, or FSH, are an indication that this reserve is declining more rapidly, which can reduce the chances of a pregnancy once a woman reaches her 30 or 40 years.
FSH levels indicate the amount of ovarian reserve.
The scientists took blood samples from patients to analyze the levels of the hormone.
The analysis showed that women belonging to blood group O showed higher readings of FSH.
On the other hand, those with blood group A had lower levels.
Dr. Edward Nejat, who led the study, says that "a woman's age remains the most important factor in determining their chances of conceiving."
"The marker of FSH gives us an idea of the quality and quantity of eggs."
But it is unclear whether this marker has any impact on the general population, he adds the scientist, because all women in the study were undergoing fertility treatments.
"Interesting
Tony Rutherford, chairman of the British Fertility Society, says the research is "interesting."
But he warns that research is needed on a larger scale to confirm the result so as to see if these effects can be detected in women who are trying to conceive but who have not been diagnosed with fertility problems.
"I think this is the first time that an investigation has found a link between blood type and fertility potential," says the expert.
"We really need to consider along with other tests, most current, measurement of ovarian reserve and study a larger group of women to see if the blood group affects the chances of getting pregnant," he adds.
