Getting Pregnant After 40. What Does Age Have To Do With Getting Pregnant?
Age is one of the most important factors affecting fertility, and therefore pregnancy. A female has a finite number of eggs. Before birth she has 7 million, and at birth only 1 million remain. By the time she reaches the age of getting periods she has 500,000 remaining, and at age 38; 25,000. Ultimately, she will have none and go into menopause after age 51.
The ever-decreasing number of eggs remaining leads to 2 important reasons of decreasing fertility:
- the first is the quality of eggs remaining in the ovary after many years are low.
- the second and most important reason is that the chromosomal health of the eggs is also compromised.
Chromosome Division Process
Half the chromosomes of the baby come from the egg and the other half from the sperm.Sperm chromosomes are constantly dividing because new sperm are generated all the time. In the eggs however the chromosomes start the division process before birth and complete it at time of ovulation, so the egg is sitting for the number of years that is the age of the female.
A 40 year old will have the eggs sitting for 40 years and at that time complete the chromosomal division. The result is errors in the division, that’s the reason incidence of downs syndrome increases with age. More importantly the body recognizes this error and prevents implantation from happening. And if it does the patient miscarries.
Once in a while the body makes an error and lets the pregnancy go further and an example is a down syndrome pregnancy, however the body is very efficient in not letting the pregnancy happen and for every abnormal baby born there are many pregnancies prevented. That is the reason that with egg donation, the age of the recipient does not affect the success rate as much because the age of the donor is the determining factor.
Embryo Health Pre-Implantation Genetic Testing
We also attempt to determine the health of the embryo through pre-implantation genetic testing. This serves a dual purpose; one is to identify the healthy embryos for implantation. The other is to guide in weather its useful to continue in attempts at utilize a patients eggs or to proceed to egg donation.