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".