The "Biological Clock" Keeps Ticking
It’s too bad biological factors and social factors aren’t always in synch. For many women, having a child in her late 30s or early 40s is ideal. She may be more established in her career, finally paid off graduate school loans, bought a new house, etc. While more women are having their first child after the age of 35, this time also coincides with the biological decline in fertility potential. One of the most challenging clinical scenarios is the impact of the aging egg on pregnancy chances. This decline in fertility potential, or "ovarian reserve", is the natural consequence of the aging process on human eggs. The clinical diagnosis is called “DOR” an acronym for Diminished Ovarian Reserve.
As background, each woman is born with a set number of eggs, predetermined before birth. This pool of eggs is never replenished. A female fetus will have the greatest number of eggs around 16-20 weeks of pregnancy (6-7 million); at birth this number decreases to about 2 million, and by puberty to about 300,000. This constant and dynamic process of decline continues until menopause, and is not interrupted by birth control pills, pregnancy, or ovulation. From this reservoir of eggs, fewer than 500 eggs will ovulate during a woman's reproductive years.
Lower pregnancy rates and higher miscarriage rates are both the consequences of the aging process, and reflective of a decline in egg quality. Women ovulate their healthiest eggs during their 20s and early 30s. By the mid 30s the remaining eggs are of lower quality, and by the early 40s only eggs with very low fertility potential are available for ovulation or ovulation induction. This phenomenon is a normal biological process, which neither fertility medications nor lifestyle changes can halt.
Although there are no clinically proven treatments for improving egg quality, fertility specialists can improve the chances of having a DOR patient conceive by being more aggressive with treatment. For instance, the clinic where I practice usually will jump straight to in-vitro fertilization (IVF) as opposed to the less invasive intrauterine insemination (known as “Artificial Insemination”) for many DOR patients. However, fertility specialists can’t be aggressive with treatment until they have patients to treat.
Here is a link that provides guidelines for when a female patient should seek help from a fertility specialist. It is categorized by age and easy to understand. I can’t emphasize enough the importance of following these guidelines.