Age plays a significant role in fertility.
There are age-related impacts on both female and male fertility, although the impact is much more significant on female fertility. Fertility is highest for females during their 20’s and early 30’s. It is estimated that the chance for achieving pregnancy for a healthy, fertile 30 year old woman is approximately 20% per cycle. By age 40, the chance for a 40 year old woman may be less than 5% per cycle. Eventually women exhaust their supply of eggs within their ovaries and cease having menstrual cycles (i.e., menopause). The average age of menopause in the United States is 51.
There is an additional decline in egg quality as women age. These changes are most noted to start in the mid-to-late 30s. As a result, there is a higher frequency of genetic abnormalities called aneuploidy (having either too many or too few chromosomes) in the eggs of older women. When aneuploid eggs fertilize, the resultant embryos similarly may have too many or too few chromosomes. Most aneuploid embryos will either not result in pregnancy or alternatively result in miscarriage. Rare cases of aneuploid embryos implanting may result is a successful birth of a child with a chromosomal abnormality (i.e., Down’s syndrome). Both miscarriages and offspring with chromosomal abnormalities rise in frequency as women get older.
Unlike the early decline in female fertility, men most often have only subtle declines in sperm quality as they age. As a result, men may still be able to father children through their 40s and 50s and even into their 60s often. In some men, there may be a decline in libido or erectile function associated with a decline in testosterone as they age.
Because of the impacts of age on fertility, we advise that older patients consult fertility centers relatively promptly (i.e., after six months of attempting pregnancy for women 35 years of age or older). Although we are not able to reverse some of these age-related fertility impacts, we are able to relatively quickly perform an appropriate evaluation and discuss recommended treatment options.