We’ve long known that there is a direct link between aging in women and men and the subsequent decline in both’s fertility - meaning they both do not have as much baby-making power in their sperm and eggs, respectively, as they did when they were younger.  Further, the quality of the sperm and eggs declines as we age, paving the way for potential complications and genetic weaknesses in the resultant baby if we have babies when we are older and the quality is lower, not the mention the likelihood of pregnancy complications goes up.

While researchers had always known that women have a harder time conceiving as they age, the impact that the man’s sperm has on that conception is much larger than was once thought, meaning the guy’s sperm contributes equally to the likelihood of conception, and the fact that an older man may be trying to impregnate a woman has a very large effect on whether that will be a successful pregnancy.

The idea from this research is that men over 40 begin to see a dwindling in the quality of their sperm, and not only that, there may also be a higher likelihood of a miscarriage in the woman they impregnate if they get pregnant from a man who is over 40 years old, so we are more likely to see more complications not only if the woman is older, but also if the man is older.

While the number of miscarriages was about the same for women who were over 40, the amount went up significantly higher if both the women and her parter were older, since the man’s sperm also contributes to the pregnancy and the successful full term of that pregnancy, and miscarriages were seen much more often when the man was significantly older, showing the importance of not only the age of the eggs, but also on the age of the sperm.