This blog explains what hormones are tested in ZRT's Fertility Profile and why each one is important.
LH & FSH are pituitary hormones, which means they affect the brain. Their communication with growing egg follicles in the ovaries is one of the only positive feedback loops in the body. On day three or four of the menstrual cycle (day one is the first day of the period) LH & FSH are at their lowest level. This relationship is normally a 1 to 1 function, but some women have LH levels that are two or three times greater than their FSH levels on day three or four of their cycle. This is a sign of polycystic ovarian syndrome (PCOS) and occurs in approximately 50% of PCOS women. The opposite problem can also occur - high FSH and LH levels.
Think of FSH and LH as calling out to the ovaries. Lower levels suggest the brain is barely whispering to call for an egg and its estrogen. Higher levels (fourteen and above) suggest the brain is shouting for eggs and estrogen. Higher levels of LH and FSH reflect that the number of eggs is decreasing. This is one of the most important tests in the fertility profile because high levels suggest that immediate assistance from a fertility specialist should be sought. Women who have very high levels can still become pregnant, but this usually requires reproductive assistance.
The ZRT Fertility Profile measures sex hormones at the mid-luteal peak, which occurs seven days after ovulation. For many women, this is generally day twenty one of the cycle; but it will fall on a different day in women with shorter or longer cycles.
Estradiol is one of three types of estrogen, and the only estrogen the ZRT Fertility Profile Tests. Estrogens are hormones that are talked about a lot with fertility because they helpto develop the uterine lining and are important for breast development. Inadequate estrogen can be a sign of lack of ovulation or low ovarian health and can impede healthy implantation of the developing embryo.
Progesterone is produced from the corpus luteum after ovulation and creates an optimally functioning uterine lining. Lower levels suggest ovulation is not occurring, an inadequate corpus luteum is being produced, or that the corpus luteum is failing before implantation occurs. Estrogen helps to build tissue and progesterone develops the tissue to accept a fertilized egg.
Testosterone is produced from the ovaries and turns into estradiol within the ovaries, which is a sign of healthy ovulation. When testosterone levels are too high, as seen in women with PCOS, the follicles and egg quality are poor. High testosterone also interferes with ovulation, which can cause cycles to become irregular. High testosterone is partially stimulated by high insulin levels.
DHEA-S is one of the primary hormones in the body and serves as a precursor to testosterone and estradiol. Low levels of DHEA-S can lead to lower estrogen levels and changes in the immune system. High levels of DHEA-S are often associated with higher insulin levels, higher testosterone levels, and PCOS.
Cortisol is a primary adrenal hormone, is produced in response to stress, and like all hormones, balance is critical. Low levels of cortisol prevent optimal thyroid function at the cellular receptors, but high levels can inhibit thyroid function and ovulation. The old saying, “Relax and you’ll get pregnant” comes from the role that cortisol plays in balancing ovulation. While it isn’t quite as simple as “relax”, balanced cortisol levels are important for ovulation and pregnancy. ZRT measures cortisol in a daily (diurnal) rhythm of four samples collected throughout the day.
Thyroid stimulating hormone (TSH) is produced in the brain’s pituitary gland and signals to the thyroid gland the need to make thyroid hormone. Because this is a stimulatory hormone, results are inversely related to the actual production of hormones from the gland; high TSH means there is low thyroid production, and low TSH means there is high thyroid production. Because it is so efficient, TSH is a great tool for assessing how happy the brain is with the amount of thyroid being produced. For fertility health, a good TSH range is generally accepted as less than 2.5. Levels of TSH greater than 2.5 are associated with poorer pregnancy and ovulation rates.
Free T4 and Free T3 are the two hormones made by the thyroid gland. They are called “free” because they are not bound to thyroid binding globulin (TBG). TBG is the protein carrier that carries thyroid all over the body. Because many things can change TBG levels, free levels are the most stable. Free T4 and Free T3 levels are important because they reveal how effective the thyroid gland is at responding to TSH stimulation.
Thyroid peroxidase antibody (TPOab or TPO) is an antibody stimulated in the gastrointestinal system by an immune reaction. The gastrointestinal immune reaction then searches for other tissue that looks like this antibody and mistakenly targets the thyroid gland. Thus, TPO is a cross-reactivity antibody, which means it is created by mistake. Thyroid autoimmunity is the most common cause of hypothyroidism. TPOab is a sign that other immune reactions are happening, which are commonly gastrointestinal parasites or food reactions. Celiac disease (the inability to process wheat gluten) is commonly found in women with TPO. Individuals with Celiac disease have a higher percentage of infertility until treated with a gluten free diet. Thyroid autoimmunity also contributes to a much higher rate of miscarriages in the first trimester.
Vitamin D3 is an optional test you can add to the existing panel. It is optional because many people have already been tested for their Vitamin D levels. If the patient has not been tested, we highly recommend women get screened. Vitamin D3 is converted in the body to a hormone that is in the same family as estradiol and thyroid. It is very important in opening receptors, or doors, in the cells. Vitamin D3 deficiency is extremely common, even in sunny climates. Vitamin D3 restoration to satisfactory levels (less than thirty two) has been found to improve fertility rates in PCOS women and women doing IVF treatments. Vitamin D3 is important in the immune system and in regulating insulin levels.