It seems nowadays everyone knows someone who has undergone fertility treatments; it even seems, perhaps, infertility is on the rise. That so many women are having trouble conceiving where as it didn't occur before. I'm not sure if that is in fact the case. Yes, there are definitely factors that cause infertility to be on the rise. For example, age is perhaps the most important factor, as women get older, there chances of conceiving become far less and their chances of miscarrying increase dramatically.
As women get older also their chances of having a baby that has birth defects also increases. The reason for this is that egg quality diminishes and egg number diminishes over time. Other factors that could be increased with age are certain uterine abnormalities. As women get older they'll often develop fibroid tumors of the uterus or certain types of ovarian cyst that can also compromise fertility. And the woman is not the only factor here, the man is also important. As men age sperm undergo more DNA changes that are not good for sperm development and can cause miscarriage in the woman. Infertility rises as men age as well.
What is not clear, however is, how often infertility occurred prior to modern times. Many women did not come out of the woodwork at that time because there was nothing that could be done. So, now I think with the advent of new treatments and great technology many of the women or many of the couples that have trouble conceiving actually due seek help, and that contributes to the high numbers of people who appear to have infertility. So, infertility might be on the rise, but we can not fully evaluate by how much, and age, uterine factors, aging of the man, and the ability to do things have contributing to the high numbers of people seeking help.