Infertility is much more common than previously supposed. In fact, the American Society for Reproductive Medicine (ASRM) reports that approximately 12 percent of all reproductive age couples experience infertility. The ASRM defines infertility as the absence of pregnancy after one year of regular intercourse for women less than 35 years old, or no pregnancy after six months for women older than age 35. Women with irregular menstrual periods need not wait 6 months or 1 year before seeking help to conceive.
Infertility is often thought of as a female problem; however, we now know that almost half of all infertile couples have a male infertility component. Therefore, we evaluate both partners for infertility causes at the outset. Male infertility can range from slight declines in sperm quality or quantity to complete absence of viable sperm. For this reason, an infertility work-up always involves testing both partners.
Infertility awareness has increased as the media focuses on high technology procedures such as IVF. However, the majority of infertile couples will become pregnant using lower tech options and will not require advanced technologies such as IVF. In many practices, less than 30 percent of couples will eventually require IVF.
Infertility causes include a decline in egg quality. Societal changes over the last twenty years have contributed to the number of women seeking infertility care. Women are choosing to start families later in life, after their careers are established, and are also waiting later to get married.
Women are most fertile in their teens and twenties and fertility declines, sometimes rapidly, in the thirties ultimately leading to the menopause. This decreased fertility is caused by a decline in egg quality and quantity. Most women are infertile by the time they reach their early forties.
Once “healthy eggs” are no longer available, the only means to achieve pregnancy is to use donor egg IVF. Donor egg success rates are typically high since we use the eggs from young healthy females.
Egg freezing is generating a lot of media attention. With egg freezing, a woman's eggs are frozen while she is fertile for use later in life. Egg freezing is being developed at Baystate Reproductive Medicine as an investigational procedure at this time, and holds promise in the future for women who wish to delay childbearing due to absence of a partner, and to those without partners who anticipate undergoing chemotherapy for various cancers.
The other causes of infertility are related to the processes that must occur for a successful pregnancy.
- Infertility causes include the male’s inability to produce enough good quality sperm to cause fertilization. The sperm must travel unimpeded through the vas deferens and be ejaculated into the vagina. Male infertility is sometimes treated using IUI or IVF with ICSI.
- One sperm must attach to and penetrate the egg membrane, injecting its genetic material into the egg, producing a fertilized egg or pre-embryo.
- The female’s ovaries must contain a supply of good quality “fertilizable” eggs. All eggs needed for a lifetime are in the ovaries at birth. Infertility caused by ovarian failure is discussed above.
- Infertility can be caused by hormone imbalances. The hypothalamus must produce gonadotropin releasing hormone (GnRH) which stimulates the pituitary to produce FSH and LH. Levels of FSH and LH are regulated by feedback from the ovary. Ovarian follicles, each containing an egg, must be recruited, grow, and mature.
- Healthy developing follicles produce estrogen, which through the mechanism begins to lower FSH production.
- Once the eggs reach maturity, the pituitary releases a surge of LH which finally prepares the eggs for ovulation and initiates ovulation 36 hours later.
- Infertility can be caused by tubal disease. Once mature, the eggs must pass unimpeded through the fallopian tubes to the site of fertilization. Tubal disease infertility, often caused by endometriosis or past infections, can interfere with egg transport.
- Infertility can result if the endometrium doesn’t develop properly. The endometrium is the lining of the uterus that must become “thicker' and more vascular during the ovulatory cycle. The endometrium provides support and nutrition to the embryo. Once fertilized, the pre-embryo enters the uterus and attaches to the endometrium. After ovulation, the follicular structure, the corpus luteum, begins to produce progesterone and estrogen thus stimulating endometrial thickening. After implantation, the placenta continues to produce progesterone. The embryo will continue to divide and grow in the uterus.
- Infertility can result if there are uterine abnormalities that inhibit the growth of the fetus. These can include congenital abnormalities, fibroids, or large polyps. Many of these conditions can be corrected surgically by an infertility specialist.
The causes of infertility and infertility treatments are complex. For this reason, a board certified infertility specialist should be consulted.
The number of board certified reproductive endocrinologists/infertility specialists has increased dramatically since the early 1990's. Infertility specialists, reproductive endocrinologists, complete OB/GYN training and board certification. They are required to successfully complete an advanced fertility fellowship program and pass rigorous examinations. Baystate’s fertility clinic has five board certified reproductive endocrinology and infertility specialists.
Infertility specialists undergo extensive training to correctly diagnose the cause(s) of infertility. They can offer the most appropriate technologies to help infertile couples achieve pregnancy.
Fortunately, with the advance of diagnostic technologies and new infertility treatments, over 80 percent of women who seek infertility specialist care will achieve pregnancy.
Learn more about the causes of infertility.