Best reproductive ages for a woman are her twenties. Fertility gradually decreases in around 30 years of age and especially after the age of 35. Chance of pregnancy is 20 percent for a healthy, fertile woman at the age of 30 in every month she tries to get pregnant. This figure also implies that pregnancy is achieved by 20 out of 100 women at reproductive age, who try to get pregnant in a certain menstrual cycle and that other 80 women should try again in subsequent periods. At the age of 40, chance of a woman is less than 5 percent in each cycle. Therefore, less than 5 out of every 100 women are expected to be successful every month.

Egg Quality Decreases as the Number of Eggs Decreases

When women are in mid 30s, their chance of pregnancy decreases and risk of miscarriage increases, since the quality of eggs reduce along with a decline in number of eggs. Thus, age of a woman is the most accurate finding for egg quality. A significant change in quality of the egg is seen in the presence of genetic anomalies, called aneuploidy (too many or few chromosome in an egg). As a woman gets older, too many or few chromosomes exist in most of the eggs. This means that there will be too many or too few chromosomes in the embryo, if fertilization is achieved. Pregnancy may fail or otherwise, it may result in miscarriage, if an embryo has too many or too few chromosomes. This fact helps explain why pregnancy rates decrease and risk of miscarriage increases in women at advanced ages.

Decrease in follicles that contain oocytes in ovaries are called as "low ovarian reserve". As women are born with all follicles they are supposed to have, the follicle pool is slowly used throughout the lifetime. As ovarian reserve decreases, follicles become less sensitive to be stimulated by FSH; therefore, more stimulation is needed for an egg to mature. First, periods may approximate to each other and this may result in short cycles at 21 to 25 day intervals. Eventually, follicles cannot react well enough for continuous ovulation and this causes long, irregular cycles. Diminished ovarian reserve is generally related to age and it is caused by natural loss of eggs and decrease in average quality of remaining eggs.

What Are Methods That Increase Success of in Vitro Fertilization For Women at Advanced Age?

Preimplantation genetic diagnosis (PGD) is a novel technique that screens all chromosomes of an embryo and may detect potential abnormalities for this group of women to increase chance of pregnancy and give birth to a healthy newborn infant. Twenty four chromosomes of an embryo are screened in genetic laboratory, after several cells of the embryo are biopsied by the embryologist without any damage to the embryo, and thus, an embryo without any genetic abnormality is selected and transferred. This method increases chance of pregnancy, ensures the continuation of pregnancy and allows giving birth to a newborn infant with normal genetic features.

Ovaries should necessarily be evaluated in the baseline examination of these women. If ovarian volume is within acceptable ranges and there are follicles that may mature in ovaries or respond to a treatment, platelet rich plasma (PRP) is injected to ovaries and small follicles that are deemed dormant can be stimulated. Thus, it is possible to get oocytes with higher quality.