There has always been talk of the age of women as a determining factor in achieving pregnancy, both naturally and in assisted reproduction processes. Nothing had been said about the age of the man so far and, in fact, there is a belief that man can be a father at any age.
But a latest study presented at the Annual Meeting of the European Society for Human Reproduction and Embryology (ESHRE) in Geneva, has shown that the age of the male partner also influences when it comes to getting pregnant.
Both the age of men and women matter
According to experts, the Women's ovarian reserve begins to decline after age 35, thus decreasing the chances of pregnancy. Men, on the other hand, do not have menopause nor do they have any "meter" of decreased fertility, so It has always been thought that his age did not affect his reproductive capacity and that they could be parents at any time in their life.
Now, a new study by the Beth Israel Deaconess Medical Center and Harvard Medical School, and presented by ESHRE, has shown that the result of in vitro fertilization is also affected by the age of the male partner, decreasing the success rate the higher he is.
"Our study has found that the age of man is an independent factor in the cumulative incidence of live births after in vitro fertilization treatment," says Dr. Laura Dodge in the report presented.
This study was carried out in an assisted reproduction clinic in Boston (United States) between 2000 and 2014. The results of 7,753 couples undergoing 19,000 cycles of IVF were analyzed..
The women were divided into four age groups: under 30 years old, between 30 and 35 years old, between 34 and 40 years old and over 40 years old. The men were divided into the same stripes but an additional strip of 42 years and more was added.
This is the first study that calculates the cumulative incidence of live births by dividing both men and women into multiple age groups, thus allowing simultaneous study of the importance that the ages of both can have
As expected, The success of the treatments was lower in those couples in which the woman was in the range of 40-42 years, regardless of the age of the man. It was once again demonstrated that the high age of women is a dominant and negative factor in achieving pregnancy.
However, in the rest of the groups, the cumulative incidence of children born alive yes it was significantly affected by the age of the male partner, and it was found to decrease as it increased.
"For example, in those couples where women were under 30 and the man was between 40 and 42 years old, the probability of success was 46 percent while if the man was between 30 and 35 years old, the chance of having a baby increased to 73 percent. Similarly, in couples with women between 35-40 years old, the rates of live-born babies were higher with younger partners than with older men. "
"In general no change is seen when women have a male partner of the same age or younger. On the other hand, when the woman is between 35 and 40 years old, it is more beneficial for the success of the treatment than the man is under 30 years old. "
Semen quality may be affected with age
Dr. Dodge notes in the report that in natural pregnancies the increase in the age of men is associated with a lower incidence of pregnancy, a greater increase in time to achieve it and a higher risk of abortion.Another study previously conducted in the United Kingdom showed that natural conception over a period of 12 months was 30 percent less likely with male partners over 40 than with men under 30.
The explanation of this decrease would be in a lower sperm count and lower quality, as well as an increase in DNA fragmentation. Increasing male age is also associated with a higher incidence of medical conditions that may affect your fertility.
"Alterations in semen parameters, increased DNA damage in sperm and epigenetic alterations in sperm that affect fertilization, implantation or embryo development have been observed" - states the report.
However, and despite the new discoveries regarding male age, both the results of this study and all previous work done continue to give more importance to the age of women than to men.
"While the effect of a woman's age on fertility is overwhelming, the effects of male age are more subtle. If we look exclusively at the woman's age, we see that the pregnancy success rate decreases to a 46 percent among women aged 40 to 42 with respect to those of 30. If we look exclusively at the age of men, the decrease in the same age range is only 20 percent "- concludes the study.
Via EurekAlert
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