If you are unable to become pregnant after one year of unprotected intercourse, or six months if you are a woman over 35, you and your partner should have a full physical and medical evaluation. Several blood tests are available to determine if you, your partner, or both of you have a problem that is causing infertility.

FSH

Follicle-stimulating hormone (FSH) helps control a woman’s menstrual cycle and the production of eggs. In men, it regulates the production and transportation of sperm.
For women, a FSH test is done on the third day of the menstrual cycle and is used to evaluate egg supply. For men, the test is used to determine sperm count.

Oestrogen

Oestradiol is an important form of estrogen. An estradiol test is used to measure a woman’s ovarian function and to evaluate the quality of the eggs. Like FSH, it is done on the third day of a woman’s menstrual cycle.

Luteinizing Hormone Level

In women, luteinizing hormone (LH) helps the ovaries to produce hormones and mature the eggs. For men, it stimulates the hormone testosterone which affects sperm production.
A  LH test is used to measure a woman’s ovarian reserve (egg supply) and a man’s sperm count. It is done during a woman’s menstrual cycle to see if she is ovulating.

Serum Progesterone

Progesterone is a female hormone produced by the ovaries during ovulation. It causes the endometrial lining of the uterus to get thicker, making it receptive for a fertilized egg.
A serum progesterone test is used to determine if a women is ovulating. The progesterone levels increase towards the end of a woman’s cycle, so the test is performed during the luteal phase of the menstrual cycle (just before her period starts).

Prolactin

The hormone prolactin is made by the pituitary gland and causes milk production during pregnancy. If prolactin levels are too high or irregular, ovulation will be affected.
In women, a prolactin test is done to find out why they are not menstruating, or why they are having infertility problems or abnormal nipple discharge. Prolactin levels are tested in men when there is a lack of sexual desire, difficulty getting an erection, or if there might be a problem with the pituitary gland.

Androgens

Testosterone is probably the most well-known androgen and it affects the sexual functioning of both men and women.
In men, an androgen test is used to find the cause of a low sex drive, the inability to get an erection, or infertility. In women, it is used to determine the cause of irregular periods or a low sex drive.