Several hormones in women work in tandem to control the reproductive cycle. Many different factors affect hormone levels, including diet, activity level, stress, metabolic disorders and other diseases. These hormones have varying normal ranges and units of measurement.
Follicle Stimulating Hormone (FSH)
Follicle stimulating hormone (FSH) is a gonadotrophin (meaning that it stimulates the gonads). During the first half of the menstrual cycle, FSH works at regulating the production of eggs and another hormone, estradiol. Normal ranges for FSH vary over the course of a woman's life; it is measured in International Units per Liter (IU/L). Prior to puberty, a normal range would be 0-5.0 IU/L. During puberty, the range should be 0.3-10.0 IU/L. During the reproductive years, 3.0-3.5 IU/L would indicate a healthy regular cycle. Post-menopausal women should be within the 40-250 IU/L range. Pregnant woman have levels too low to measure, as there is an absence of menses during pregnancy.
Luteinizing Hormone (LH)
Luteinizing hormone is another gonadotrophin. It induces ovulation of mature eggs during the preovulatory LH surge. After ovulation, residual cells in ovulated eggs convert to new cells that specialise in the production of progesterone and estradiol. LH also stimulates sex steroids that induce the conversion of testosterone to oestrogen within granulosa cells in the ovary. A normal range would be 5-10 IU/L, peaking during menses.
In pregnancy, progesterone assists in the preparation of the uterine wall for pregnancy. It also keeps the body from rejecting the pregnancy; levels that are too low can cause miscarriage. Progesterone levels also drop prior to childbirth. Measured in nanograms per millilitre (ng/ml), prior to ovulation, levels should measure 1 ng/ml or less. Midway through the menstrual cycle, 5-20 ng/ml is acceptable. After menopause, levels will drop below 1 ng/ml. During pregnancy, levels vary during each trimester. First trimester in a normal pregnancy will register between 11.2 and 90.0 ng/ml. Second-trimester levels should be 25.6-89.4 ng/ml and during the third trimester 48.4-42.5 ng/ml.
Oestrogen refers to a group of primarily female sex steroids. Estradiol is the most powerful in women prior to menopause; it controls the growth of the female sex organs, as well as height and fat distribution in women. It is measured in picograms per millilitre, and in premenopausal women it should measure 30-400 pg/ml. Post-menopausal, it will measure 0-30 pg/ml.
Prolactin stimulates breast growth and milk production in women. Many medications can have effects on prolactin production both stimulating and reducing; certain foods can have a stimulating effect on prolactin. Measured in nanograms per millilitre (ng/ml), it should measure 2-29 ng/ml for women who are not pregnant and 10-209 ng/ml for pregnant women.