Over the last several years, it appears that the incidence of infertility is increasing. This may be due to increased public awareness causing people to question their fertility and to seek help. Women are marrying at older ages and many are delaying childbirth until they establish their careers. Unfortunately, many don’t consider the “fertility implications” of waiting until their mid or late thirties to attempt pregnancy.
If society adhered to the biologic clock, pregnancy would be attempted in the teens and early twenties, during the most fertile time of a woman’s life. Obviously, this does not mesh with the societal clock as most women want to achieve more emotional maturity and develop the ability to properly support a child. It can be extremely frustrating and depressing to discover that having a much desired child will require fertility treatments.
The American Society for Reproductive Medicine (ASRM) defines infertility as the inability to conceive after one year of unprotected, regular, intercourse. The time is shortened to six months in women aged 35 and older.
It is clear that advancing female age is the “number one enemy” of female fertility. There is a direct correlation between age and fertility and fertility can decline very rapidly. This is one reason why a fertility specialist must be consulted early in the course of a couple’s infertility.
A female is born with a lifetimes’ supply on eggs within her ovaries. Each month an egg(s) is recruited and develops until maturity and is ovulated. The hypothalamus is the master gland that controls the processes of egg development and ovulation. It monitors the levels of various hormones and adjusts the output of others in a system termed the “hypothalamic-pituitary-adrenal axis”.
During the first days of the ovulatory cycle, the hypothalamus secretes gonadotropin releasing hormone (GnRH) which travels to the pituitary where it stimulates the production of follicle stimulating hormone (FSH). FSH directly stimulates the ovaries causing the recruitment of follicles (each of which containing an egg). As healthy follicles develop, they produce increasing amounts of estrogen. Estrogen travels to the hypothalamus where its levels are monitored and the production of FSH is adjusted accordingly.
Once the follicles mature, the hypothalamus releases GnRH which stimulates the pituitary to produce a surge of luteinizing hormone thus initiating ovulation. The leftover ovarian follicles begin to produce progesterone and are now termed the corpus luteum. Progesterone is needed to support development of the endometrium which will support the embedding embryo and resultant fetus.
Infertility results when any of these processes do not occur properly. Also, it is estimated that up to half of all couples will have a male component to their infertility. An evaluation of both partners is mandatory.