Overview of Infertility
Infertility is the inability to conceive and become pregnant after 12 months of regular, unprotected sex at the time of ovulation. Infertility is a common medical condition, affecting approximately 6 million people in the United States every year. It is estimated that about 1015 percent of heterosexual couples who try to conceive are unable to do so after 1 year of trying. According to the Centers for Disease Control and Prevention (CDC), about 1.5 million women (6 percent) in the United States are affected by infertility.
Twelve months may seem like an arbitrary length of time, but it makes sense, given that most fertile couples become pregnant within a year. So if a couple does not conceive after a year of effort, it is likely that the man, the woman, or both partners are infertile.
Infertility affects men and women equally. Eighty percent of infertility cases have a known cause, and half of these are wholly or partially due to male infertility factors, most commonly azoospermia (the absence of any sperm) or oligospermia (the presence of too few sperm).
Infertility in women is usually due to anovulation (absence of ovulation), blocked fallopian tubes, uterine abnormalities or immunological causes.
A family history of systemic lupus erythematosus (SLE), rheumatoid arthritis, stroke, or heart attack can indicate a blood clotting disorder, which may be a contributing factor in female infertility, second and third trimester miscarriages, and stillbirths. Blood clotting disorders can prevent normal nourishment of the placenta, causing intra-uterine-growth-retardation (IUGR) or intra-uterine-fetal-death (IUFD). Autoimmune factors, such as endometriosis, anti-thyroid antibodies, anti-sperm antibodies, and activated natural killer cells, also may contribute to infertility.
Conception and pregnancy are complicated processes involving many biologic factors and phases:
- the man needs to produce healthy sperm and the woman healthy eggs;
- the cervical mucus needs to be healthy and abundant so that the sperm can travel up through the cervical canal to the uterus and fallopian tubes;
- the fallopian tubes need to be open and accessible so that the sperm can reach the egg;
- the sperm has to be able to fertilize the egg when they make contact;
- the fertilized egg (the embryo) has to be able to implant in the woman's uterus; and, finally,
- both the embryo and the woman's uterine environment need to be healthy and strong for the baby to come to term.
If any one of the biologic factors is impaired or damaged in any way, infertility can result. Infertility in women has been linked to aging, a history of pelvic inflammatory disease (PID), and certain lifestyle behaviors.
Infertility diagnosis involves an infertility workup. Treatment for infertility may include medication, surgery or in vitro fertilization (IVF). About 25–30 percent of all couples who receive treatment are able to conceive.
Success with IUI or IVF is related to the patient's age—older patients have lower success rates. Sex-steroid markers that may be used to determine egg quality or ovarian reserve include FSH (normal is 6–10) and E2 (estradiol; normal range is 25–65). Other factors involved in the initial evaluation include prolactive levels, progesterone levels, LH (luteinizing hormone), and TSH (thyroid-stimulating hormone).
Any of these factors that are outside of the normal range can point the reproductive endocrinologist in the right direction for creating an appropriate and often successful treatment plan.