A couple is considered infertile if no pregnancies have occurred during at least 1 year of unprotected intercourse. However, studies on the probability of fertility over time suggest that this interval may be too short, because 15% of couples fail to achieve pregnancy in 1 year but only 6% fail by the end of 2 years.5,6 Basic evaluation reasonably can begin after 1 year of infertility, as can relatively low-cost appropriate therapy, but the use of expensive and specialized procedures should probably be reserved until after 2 or more years of infertility.

At the initial evaluation, the man and his partner should be questioned about libido and erection (see Chap. 117), coital technique, frequency, and timing of intercourse. Although uncommon,
people who lack understanding of simple reproductive physiology can reduce fertility by the practice of premature withdrawal, coitus associated with the time of menses rather than midcycle, or abstinence except for an erroneously perceived fertility period. Obviously, the timing of intercourse close to the time of ovulation is essential. For most couples, this optimal time is ˜11 to 13 days after the onset of menses. Basal body temperature records can be useful, relying on the progesterone-induced temperature rise, but these records are often confusing for patients. Home kits are available to assist the timing of intercourse by monitoring for the appearance of luteinizing hormone (LH) in a woman’s urine, indicating the preovulatory surge of LH.

A critical feature of the initial assessment is consideration of the female partner’s reproductive potential. Although obvious menstrual irregularity can be ascertained by history, subtle dysfunction may require careful gynecologic evaluation. Female factors that frequently may be unrecognized include abnormal coital habits, cervical factors, tubal obstruction, anovulation, oli-gomenorrhea, short luteal phase, hyperprolactinemia, and age. The evaluation of both partners should proceed simultaneously. Frequently, correction of a female factor markedly improves fertility rates among couples in whom the problem initially had been assumed to be a male factor (see Chap. 97 and Chap. 103).

The medical history of the infertile man should focus on identifying factors that are known to impair erectile or testicular function and excluding mild forms of systemic illness that can be associated with reduced sperm production7,8 (see Chap. 116). Major risk factors include late or incomplete testicular descent, abnormal pubertal development, inadequate libido or potency, retrograde ejaculation, genital infections, drugs (including alcohol and marijuana), toxins (including pesticides and radiation), heat (including prolonged fever), cancer therapy, and systemic illness. Failure of complete testicular descent or late descent can cause permanent germ-cell injury (see Chap. 93). In utero exposure to diethylstilbestrol is associated with epididymal abnormalities that can cause obstructive azoospermia.9 Late or incomplete puberty can indicate hypogonadism, especially when associated with partial or complete impotency (see Chap. 92 and Chap. 115). Failure to ejaculate, despite a normal erection and the sensation of orgasm, indicates retrograde ejaculation.10 Genital infections, especially chronic epididymitis and prostatitis, can markedly diminish sperm motility and fertility.11 Mumps orchitis can cause progressive tubular sclerosis and irreversible damage to the seminiferous epithelium and to Leydig cells.12 Personal habits can lead to testicular injury, especially heavy alcohol intake, bathing in hot water, and frequent marijuana use.13,14 Occupational exposures to radiation, certain pesticides such as dibromochloropropane, and aromatic solvents are associated with reduced fertility15,16 and 17,17a (see Chap. 235). Treatment of cancer by radiation or chemotherapy can severely impair sperm production.18 Pelvic trauma or pelvic surgery can injure the gonads, or the accessory organs and ducts, or damage pelvic nerves, causing erectile or ejaculatory dysfunction. The effects of systemic illnesses on testicular function are discussed in Chapter 116.