Male factor is the sole cause of infertility in 20% of infertile couples and may be a contributing factor in as many as 40% of cases. Treatment of reversible endocrine or infectious causes of subfertility, such as sexually transmitted diseases and thyroid disorders, tends to be efficacious. Intrauterine insemination (IUI) is the best studied and most widely practiced of all the insemination techniques. Intracytoplasmic sperm injection (ICSI) has allowed couples with male factor infertility to achieve assisted reproductive technology (ART) pregnancy outcomes that are comparable with those of couples with non–male factor infertility using conventional in vitro fertilization (IVF) treatment.
An association between the age of the woman and reduced fertility is well documented. The decline in fecundability begins in the early 30s and accelerates during the late 30s and early 40s.
Disorders of ovulation account for about 20% to 40% of all cases of female infertility. These disorders are generally among the most easily diagnosed and treatable causes of infertility.
The most common cause of oligo-ovulation and anovulation—both in the general population and among women presenting with infertility—is polycystic ovarian syndrome (PCOS).
Tubal and peritoneal factors account for 30% to 40% of cases of female infertility. Cervical factor is estimated to be a cause of infertility in no more than 5% of infertile couples. Uterine pathologies constitute the etiologic factor in infertility in as many as 15% of couples seeking treatment and are diagnosed in as many as 50% of infertile patients. Leiomyomas have not been shown to be a direct cause of infertility.
All methods of ART, by definition, involve interventions to retrieve oocytes. These techniques include IVF, ICSI, gamete intrafallopian transfer (GIFT), zygote intrafallopian transfer (ZIFT), cryopreserved embryo transfers, and the use of donor oocytes. Because of improved success rates associated with IVF-embryo transfer, the performance of GIFT and ZIFT has declined.
Multiple gestation, especially higher-order multiple gestation, is a serious complication of infertility treatment and has tremendous medical, psychological, social, and financial implications and complications.
Fortunately, recent studies have not shown an increased risk for breast, uterine, or ovarian cancer secondary to medications used for superovulation in the treatment of infertility.
Information on the Society for Assisted Reproductive Technology (SART) and registered ART clinics are accessible on the Internet.
Infertility is defined as 1 year of unprotected intercourse without pregnancy (1). This condition may be further classified as primary infertility, in which no previous pregnancies have occurred, and secondary infertility, in which a prior pregnancy, although not necessarily a live birth, has occurred. About 90% of couples should conceive within 12 months of unprotected intercourse (2). Subfertility refers to couples who conceive after 12 months of attempted impregnation (2). Fecundability refers to the probability of pregnancy per cycle, which is considered to be at 20% in fertile couples (1). Fecundity refers to the probability of achieving a live birth in a single cycle and, by definition, has a value lower than fecundability. The diagnosis of impaired fecundity has been proposed to include couples with 36 months or more without conception or physical inability or difficulty in having a child; however, there is currently no clear consensus on any of these terms (3–5).