Fertility testing

Fertility testing is the process by which fertility is assessed, both generally and also to find the "fertile window" in the menstrual cycle. General health affects fertility, and STI testing is an important related field.

Healthy women are fertile from puberty until menopause, although fertility is typically much reduced towards the extremes of this period. The onset of puberty is typically identified by menarche and the presence of secondary sexual characteristics such as breast development, the appearance of pubic hair and changes to body fat distribution. The end of fertility typically comes somewhat before menopause, as fertility declines to a point where establishing a viable pregnancy is very unlikely.

Various methods of predicting the timing of ovulation exist, some of which may be performed at home or in a clinical setting. Knowing the timing of ovulation can help a woman to determine the days of the menstrual cycle that are most likely to result in conception.

The cervix is a structure between the vaginal canal and the uterus. The cervical cells secrete mucus that changes its consistency over different parts of the menstrual cycle. During the fertile window, the mucus increases in quantity and becomes clear and stretchy and is known as "egg-white cervical mucus." This mucus allows sperm to survive in and travel through it. In contrast, when outside of the fertile window, the mucus does not stretch, is sticky, and is not clear.

The stretch test can be performed prior to and immediately after urination. Mucus can be sampled with by either wiping with toilet paper or inserting a clean finger into the vagina. The mucus quality can then be observed by stretching the mucus between the finger and thumb as shown in the image.

Urinary ovulation prediction kits are typically found over-the-counter and there are many brands to choose from. This test measures the amount of luteinizing hormone, a hormone that increases just before ovulation, that is in the urine. Before ovulation, the luteinizing hormone levels dramatically increase; this is known as the "LH surge". This test can recognize the LH surge about 1-1.5 days prior to ovulation. Additionally, some ovulation prediction kits detect estrone-3-glucuronide. This is a breakdown product of estrogen and will have increased levels in the urine around the time of ovulation. This test is able to detect luteinizing hormone and estrone-3-glucuronide 90% of the time.

This test can be used in multiple ways. A few drops of urine can be added to the test device tip. Alternatively, the test device tip can be held in the urine stream. Finally, the test device tip can be dipped into a cup of urine. The test will indicate positive or negative results in about five minutes.

A fertility monitor is an electronic device which may use various methods to assist the user with fertility awareness. A fertility monitor may analyze changes in hormone levels in urine, basal body temperature, electrical resistance of saliva and vaginal fluids, or a combination of these methods. These devices may assist in pregnancy achievement. An updated 2023 Cochrane review has found that the use of urine ovulation test probably improves life births in women under 40 but that further study on risk and benefits is needed on timed intercourse via the use of these test.