National statistics indicate that as many 4 million of an estimated 35 million cohabiting heterosexual couples in the United States are infertile (i.e. unable to conceive within a year of trying). Saturday, April 24th, marked the start of National Infertility Awareness Week (NIAW), which is intended to make aspiring parents aware of their vulnerability when it comes to fertility and the need to take charge of their reproductive options.

Most individuals and couples take their fertility for granted, believing that upon trying, they will easily and readily conceive. After all, their parents and friends seem to experience no difficulty in getting pregnant, so why should they? Nothing could be further from reality! The truth is that fertility potential in fact can vary widely from one couple to another with some conceiving right off the bat while others are unable to do so after at least a year of consistent trying (this is infertility by definition). The need for early and regular assessments of fertility potential is even more essential for women than for men, as all women will inevitably experience diminishing “fertility potential” with advancing age. This decline usually starts after age 35 but it many cases, it can and indeed does begin much earlier.

The causes of infertility are diverse and are more or less evenly divided between the female and male. Blocked or damaged fallopian tubes, endometriosis, uterine implantation problems (usually due to anatomical disease or immunologic factors), and advancing age associated with declining egg quality, are among the commonest causes of female infertility.

When it comes to the man, blockage of the sperm ducts, reduced testicular function due to environmental toxins, radiation, chemotherapy, heavy metal poisoning, delayed descent of the testicles into the scrotum and varicocele, are among the commonest causes of male infertility. In addition, many (if not most) of reasons for male infertility are as yet “unexplained”. Because of ignorance, vanity, machismo, or denial, most men fail to see a physician for reproductive evaluation without being prompted. As a result male infertility is more likely than female infertility to go undetected for long periods of time.

As stated above, there is a wide diversity in “fertility potential” among couples and individuals. It is therefore advisable that those contemplating having a baby undergo a thorough reproductive assessment sooner rather than later in their relationships. Moreover, such evaluations should ideally be repeated every few years.

A woman’s egg quality/competence declines beyond her mid 30’s, as does her ovarian reserve (the number of eggs she is able of producing per cycle). In some cases it falls off much sooner. Thus, while young women usually have the time to address fertility issues, this is not invariably the case. The earlier they become aware of a possible problem, the more time they will have available to address and correct it before potentially irreversible egg quality issues deny them the opportunity to do so effectively.

The egg (rather than the sperm) is the main determinant of post-fertilization embryo competence and overall reproductive potential, and egg quality inevitably is linked to the woman’s age. At 30 years old, about 40% of a woman’s eggs are genetically normal. At 35 years…..about 25%, at 40 years …about 15%. Beyond the mid forties, probably no more than 10% are capable of making a baby. Moreover, the closer the woman gets to the menopause, the fewer viable, competent eggs she is capable of yielding (we refer to this as diminishing ovarian reserve). It follows that age and proximity to the menopause need to be carefully monitored. Diminishing ovarian reserve can be detected from rising blood follicle stimulating hormone (FSH)levels, declining Inhibin B levels and declining Anti-Mullerian Hormone levels early on in the menstrual cycle.

While most American women will experience declining ovarian reserve after age 35, and menopause between 40 and 50 years of age, this can occur much earlier. In fact, some women will go into a premature menopause with declining ovarian reserve beginning as early in their mid 20’s or early 30’s. In such cases, there will usually be no clear warning signs in the early stages. This serves to underscore the need for early baseline evaluation of ovarian reserve, and regular (at least biannual) monitoring of these same parameters after the age of 30.

With a few notable exceptions, most causes of female infertility will often be picked up in the course of regular physical and ultrasound examinations. The exceptions are endometriosis (the development of endometrial implants on pelvic organs), which can only be definitively diagnosed by direct visualization by open surgery or laparoscopy, and damage to the fallopian tubes, which can only be recognized through invasive tests such as a dye x-ray evaluation (hysterosalpingogram) or laparoscopy. It follows that failure to conceive after a year of trying should prompt evaluation of 1) fallopian tubal function and 2) endometriosis. Both are treatable surgically or through assisted reproduction (e.g., IVF).

In my opinion, all men should have a semen analysis performed immediately prior to, or upon committing to a relationship in which they wish to father a child. The sooner this is done, the better; in doing so the man would have a better idea as to the existence and severity of fertility issues. Men with a history of undescended testicles at birth, testicular injury or swelling, prior venereal infection, mumps causing testicular enlargement, exposure to heavy metals, or pain in the testicular region should probably undergo a semen analysis even before contemplating fatherhood.

Always remember that even in the absence of any symptoms or signs of male or female infertility, there is always the possibility that a woman’s cervical secretions might be hostile to the man’s sperm. That is why, along with a comprehensive reproductive evaluation, I recommend the performance of a post-coital test around the time of natural ovulation when clear mucus is exuding from the cervix (the opening to the uterus) . The test is ideally performed soon after intercourse to evaluate sperm-mucus interaction. Failure of sperm to survive in this environment often points towards a significant barrier to fertility…. one that requires (and is often quite amenable to) medical correction.

National Infertility Awareness Weekshould serve as a strong reminder that reproductive potential is highly vulnerable to internal and external influences and should never be taken for granted. Information represents empowerment and without it comes both disappointment and heartache.