The woman

• Charting basal body temperature (BBT) at home to identify ovulation phases, often for a few menstrual cycles before considering medical testing. Use a simple Fahrenheit temperature chart(What is a PDF document?) or Celsius temperature chart(What is a PDF document?) to track your temperature for a few months. Many doctors recommend that women use a home ovulation test kit to test luteinizing hormone (LH) levels in urine to confirm that ovulation occurs within 12 to 36 hours of your temperature increase.

Both the man and the woman

• Medical history and physical examination
• Chlamydia test, because untreated chlamydia can cause female infertility and can infect a newborn at birth.

The man

• Semen analysis, to check the amount and quality of semen and sperm and for signs of infection. Abnormal test results are usually confirmed with another semen analysis, then followed with testosterone and FSH tests.

The man or the woman

Hormone tests, to check for a woman's ability to ovulate or a man's ability to produce sperm. These may include:

• Luteinizing hormone (LH). Abnormal LH levels can be a sign of female ovulation problems or male testosterone production problems.
• Progesterone. Low progesterone levels can be a sign of ovulation problems.
• Follicle-stimulating hormone (FSH), sometimes followed by a more specific clomiphene challenge test of the egg supply. High FSH levels may be a sign of low egg supply, or ovarian reserve; low FSH levels can prevent ovulation or, in men, sperm production.
• Thyroid-stimulating hormone (TSH). Abnormal thyroid function can affect the menstrual cycle and ovulation.
• Prolactin. High prolactin can be a sign of a pituitary problem, which can affect ovulation.
• Testosterone. Low testosterone in men can cause sperm production problems. High levels in women can cause irregular menstrual periods.

No test provides absolute proof that the ovaries are releasing eggs. But basal body temperature charting, LH, and progesterone testing can provide strong evidence of ovulation.

The woman

• Pelvic ultrasound to study egg follicle development
• Hysterosalpingogram or sonohysterogram (through the vagina) to check the uterus and fallopian tubes for signs of damage or structural problems
• Hysteroscopy (through the vagina) to examine the uterus, sometimes done in addition to a hysterosalpingogram
• Laparoscopy (through an abdominal incision) to look for and possibly repair conditions such as uterine fibroids, scarring from pelvic inflammatory disease, or endometriosis that can prevent pregnancy

Both the man and the woman

• Sperm antibody test to see whether the man's or woman's body is producing antibodies that impair the sperm, possibly preventing pregnancy

The man

• Testicular biopsy (through an incision, rarely used) for men lacking sperm, to see if the fertility problem is linked to a sperm production problem in the testicles

Both the man and the woman

• Genetic test, to see whether a genetic problem is contributing to infertility and/or to assess for possible genetic disorders that a parent could pass on to a child. Many, but not all, genetic conditions can currently be identified.
• Testing semen and cervical mucus, to check for infection that should be treated before trying to start a pregnancy