Laboratory tests provide insight to how your body is functioning. This information is combined with your other diagnostic findings to determine the most successful course of treatment.
- Androgens: small amounts of androgens—testosterone and DHEAS (dihydroepiandrosterone sulfate)—are normally produced in women. Excess production may interfere with development of the follicles, ovulation, and cervical mucus production.
- Prolactin: stimulates milk production; blood levels may be higher than normal with certain disorders or if you are taking certain medications
- Thyroid: an underactive thyroid (hypothyroidism) can result in high prolactin levels
The endocrine system refers to the collection of glands that secrete hormones directly into the circulatory system to be carried towards distant target organs. The major endocrine glands include the pineal gland, pituitary gland, pancreas, ovaries (in females), testes (in males), thyroid gland, parathyroid glands, hypothalamus, and adrenal glands.
As part of the endocrine system the ovaries produce female sex hormones estrogen and progesterone. These hormones regulate the menstrual cycle and also play a very important role during pregnancy.
The pituitary gland contributes by regulating the sex hormones through the follicle-stimulating hormone (FSH) and the luteinizing hormone (LH). The FSH and the LH ensure proper functioning of the reproductive system. The FSH stimulates the maturation of ovarian follicles in the ovaries and LH helps in ovulation in females.
Since all components of the human body work in concert with each other, hormonal balance outside the reproductive system is extremely important to conception.
As part of the endocrine system, there are four main hormones that are responsible for sperm production:
Gonadotropin (GnRH): Gonadotropin, which is released from the hypothalamus, plays a vital role in human sperm production as it coordinates the release of the other hormones that are also involved in the production of sperm, specifically luteinizing hormone (LH) and follicle-stimulating hormone (FSH) that are released from the pituitary gland.
Follicle-stimulating hormone (FSH): Produced in the pituitary gland, this hormone plays a vital role in the production of sperm and stimulates the germ cells in both males and females to mature.
Luteinizing hormone (LH): In men, LH works together with FSH to produce sperm.
Testosterone: As a male makes his way through puberty, testosterone plays a major role and his testicles start producing more and more of this important hormone. Testosterone is another hormone that stimulates the production of sperm. As well, testosterone is very important for the development of the male reproduction tissues like prostate and testes.
A woman’s ability to get pregnant normally decreases as she gets older. In later life, women have fewer eggs, egg quality goes down, and eggs have more abnormalities in their chromosomes (genetic material). All these factors together mean that older women have lower pregnancy rates and higher miscarriage rates.
The ability to have a baby decreases in all women as they get older, but the exact age when a woman can no longer conceive varies from woman to woman. In some women, this happens at a younger age than would normally be expected. About one third of couples will have problems getting pregnant when the female partner is age 35 or older. There are several tests that can help show a woman’s fertility potential, also called ovarian reserve.
Blood tests: FSH, Estradiol, and AMH
One common way to test ovarian reserve is by measuring hormone blood levels. Follicle-stimulating hormone (FSH) and estradiol are checked at the beginning of the menstrual cycle. This is usually done on cycle day 3, but it can be drawn from day 1 to 5. These hormone levels can show important information about how the ovaries and pituitary gland are working together.
The pituitary gland makes FSH to make a follicle grow. A follicle is a small cyst that contains the egg. Usually, FSH levels are lowest in the beginning of the menstrual cycle and then go up, causing a follicle to grow and the egg to mature. As this happens, the follicle releases estradiol. In turn, these higher levels of estradiol tell the pituitary gland to make less FSH. If the egg and follicle start to grow too early because FSH is already rising, estradiol is produced faster. If development is too fast, the egg does not mature properly.
In general, women whose cycle day-3 levels of FSH and/or estradiol are high are less likely to have a baby after either ovulation induction or in vitro fertilization (IVF) compared with other women of the same age.
Antimüllerian hormone (AMH) is another test of ovarian reserve. It is made in the follicle and is related to the number of eggs. AMH levels can be drawn at any time during the menstrual cycle.
You should know that laboratory procedures and “normal” levels vary from lab to lab. It can be difficult to compare results from one laboratory to another.
Clomiphene Citrate Challenge Test
This test involves taking a medicine called clomiphene citrate to see how the ovaries respond. It is given early in the menstrual cycle. Blood levels of FSH and estradiol are measured before and FSH is measured after clomiphene citrate is given. Women have lower pregnancy rates with both ovulation induction therapy and IVF if their FSH levels are high at either time.
Antral follicle count
A transvaginal ultrasound may be done in the early part of the menstrual cycle to count the number of small (2mm-10mm) follicles in the ovary. These are called antral follicles, and are where eggs develop. The number of antral follicles can tell us how many eggs are available and about the woman’s response to gonadotropin medicines. This test is more accurate when it is done by a health-care provider who is experienced in working with fertility evaluations.
Response to Gonadotropins
Gonadotropins are hormone medications (FSH alone or FSH with luteinizing hormone) that are given to stimulate the ovary to grow multiple eggs at once. They are given by injection to prepare a woman for fertility therapies.
Higher doses of these medicines are usually needed to help with egg development as a woman gets older. Women who require large, or larger than expected, amounts of gonadotropins generally get pregnant less often with both ovulation induction therapy and IVF.
What these tests tell us
These tests try to predict a woman’s response to fertility treatment and how likely she is to get pregnant compared to other women of the same age. Abnormal ovarian reserve test results suggest that fertility potential has declined but they do not tell who will or who will not conceive. Some younger women with normal test results have difficulty conceiving. Results may vary from cycle to cycle; however, any one abnormal test generally shows that fertility potential has decreased.
The chance of getting pregnant is primarily related to the quality of the eggs. Women over the age of 35 with abnormal test results who have not had successful treatment have a lower chance of conceiving. These women may be candidates to use eggs or embryos from a donor. Even with a normal ovarian reserve test, older women may have difficulty conceiving.
No single test of ovarian reserve can predict a woman’s ability to get pregnant. These tests are often used to develop a treatment plan, including the need for donor eggs or embryos.
Though not directly related to your fertility, these labs allow us to guide you on a safe and healthy journey to parenthood.
- Hepatitis B surface antigen – a screening test for the hepatitis B virus
- Hepatitis C antibody – a screening test for the hepatitis B virus
- Human immunodeficiency virus (HIV) – a screening test for the HIV virus
- Rapid plasma reagin (RPR) – a screening test for syphilis
- Rubella titer (Females only) – you will need this test just once; it checks for antibodies in the blood that develop in response to a rubella infection or immunization
- Blood group – to determine your blood type
- Rhesus factor (Rh) – you will need this test just once; it checks for an inherited protein found on the surface of red blood cells. If your blood has the protein, you’re Rh positive. If your blood lacks the protein, you’re Rh negative. Having an Rh negative blood type is not an illness and does not affect your health. However, because it can affect your pregnancy, your pregnancy will require special care if you’re Rh negative and your partner is Rh positive.
- Complete blood count (CBC) – this test gives important information about kinds and numbers of cells in the blood, especially red blood cells, white blood cells, and platelets. Abnormal increases or decreases in cell counts may indicate an underlying medical condition that calls for further evaluation.
DIRM is truly a place where dreams, through science, become reality.