There are many reasons why women require the assistance of an egg donor in order to conceive a child, but the most common reason is the woman’s age. 

MATERNAL AGE OVER 40 

Most recipients of egg donation are between age 43 and 47.  A woman is born with about 500,000 eggs and they begin to age the moment she is born.  A woman’s fertility begins to decline dramatically around age 35, and continues to decline steeply until it ends completely several years prior to menopause which occurs at age 50 to 55.  The decline in fertility is not because she is not running out of eggs but rather because her eggs are aging. 

The 23 chromosomes in an egg become damaged or broken over time and so they are less likely to successfully fertilize to become an embryo.  Also the resulting embryos are more likely to be damaged and thus may not produce a healthy embryo that will successfully implant and develop into a mature fetus.  Therefore even when a woman over 35 does become pregnant, the rate of miscarriage increases dramatically. At age 40 the rate is over 40% and by 45 the miscarriage rate is 50% to 80% (studies vary). 

Most older women who are seeking the assistance of an egg donor are not technically “infertile” in that they are still capable of conceiving.  It’s just that their mathematical probability of conceiving a pregnancy that continues to maturity is much lower.  Among couples over 35, approximately one third with have difficulty conceiving. 

These days many women postpone starting a family for a variety of reasons:  they haven’t found a partner yet, they are focused on their careers, they don’t feel financially prepared for parenthood, they divorced before having children and are seeking to create a family in a second marriage, etc.  Fortunately, with modern medical technology and the young women who are willing to be egg donors, these women do not have to give up on their desire to have a family.  An egg donor cycle usually results in about 4 to 8 good quality embryos and many couples are able to have more than one child from one egg donor cycle.  Egg donation has been in use for over 30 years and over time the process has steadily improved and success rates have improved dramatically.

OTHER REASONS TO REQUIRE AN EGG DONOR 

There are other reasons that a woman may need an egg donor such as a lack of ovaries, congenital conditions that prevent conception, prior chemotherapy that has damaged the ovaries, and others.  While some egg donor recipients have already gone through unsuccessful attempts with IUI, IVF with their own eggs, etc.  there are some couples who will go straight to egg donation knowing that is the only viable option for them.

OTHER CAUSES OF FEMALE INFERTILITY 

There are other causes of infertility in women that are not related to egg quality such as conditions affecting her uterus or fallopian tubes.  These conditions do not require the use of an egg donor.   They include things such as uterine fibroids or polyps, or endometriosis, or fallopian tubes that are blocked or damaged due to pelvic inflammatory disease (PID) or other causes. 

Fallopian tube problems may be dealt with by circumventing the tubes using IVF. In IVF her own eggs are retrieved directly from her ovaries so that they do not need to pass through the fallopian tubes.  The eggs are then fertilized in the lab and the resulting embryos are transferred to her uterus. 

Uterine issues such as polyps or fibroids must be dealt with directly by surgical removal. Endometriosis can be more challenging to treat and often these women are unable to carry a pregnancy and must use a gestational carrier to carry the pregnancy for them.

CONCLUSION 

While there are many causes of female infertility, the most common reason that women require the use of ART, or Assisted Reproductive Technology is the woman’s age.  These days the use of ART is fairly common and fortunately much of the stigma around it has diminished.  There are many resources including books, support groups, blogs, etc.  for women who require the use of egg donation and they are definitely not alone.  There is a whole world of women out there who are on the same journey.