Learn about different types of blood tests used in fertility testing so you can be prepared when starting your journey.

The process of trying to conceive a baby can be unpredictable and challenging. If you have been struggling to become pregnant, you may be wondering if it is time to seek out assistance from fertility specialists.

Infertility, or the inability to conceive a baby after 12 months (6 months for women over the age of 35) of regular unprotected sex, is a common issue that affects both men and women. Infertility may occur for various reasons, and there are many assessments that may be used to evaluate reproductive health and determine potential causes.

In this article, we cover some of the basics about fertility blood tests—from what types exist and what they measure all the way through preparing for your own results—so you can better understand how these assessments can help inform your plans for creating a family.

When should I start thinking about fertility testing?

Fertility testing is an important step for evaluating reproductive health and functioning. It may be appropriate if:

  • You and your partner have been having regular unprotected sexual intercourse  for a year and have yet to conceive.
  • You are a woman over the age of 35 and have not gotten pregnant after six months of regular unprotected sexual intercourse.
  • You have been diagnosed with a disorder or condition that impacts your reproductive system and fertility. For women, this may include endometriosis, polycystic ovarian syndrome (PCOS), and uterine fibroids. For men, this may include testicular cancer and cryptorchidism (a condition where one or both testicles has not descended to the scrotum).
  • You are a woman in a same-sex relationship and are planning to pursue assisted therapies, such as in vitro fertilisation (IVF) or intrauterine insemination (IUI).
  • You are considering gender-affirming surgery (procedures that alter primary or secondary sexual characteristics to match one’s gender identity) and would like to explore fertility preservation options.

What kinds of fertility tests are there?

In addition to blood and hormone tests, common methods for evaluating fertility are ovulation testing, semen analyses, and imaging tests, such as a transvaginal ultrasound or a hysterosalpingogram (an x-ray test used to evaluate the shape of the uterine cavity and the shape and openness of the fallopian tubes). In some cases, your fertility specialist may suggest procedures, such as laparoscopy or hysteroscopy, or genetic testing.

Who are fertility blood tests for?

Fertility blood tests are for both men and women who have difficulty getting pregnant or are experiencing other fertility-related issues. Additionally, they may be used for women considering egg freezing. These tests may be used to detect hormonal imbalances, assess testicular and ovarian function, and determine potential reproductive disorders.

Common fertility blood tests

There are a variety of blood tests that your fertility specialist may use to measure your hormone levels and identify potential fertility problems. In this section, we go over 10 of the most common blood and hormone tests.

Keep in mind that normal hormone levels are defined according to a variety of factors, including your sex and age. Additionally, the results of a blood test alone are not a measurement of your fertility.

Follicle-stimulating hormone (FSH) test

This test measures the level of follicle-stimulating hormone (FSH) in the blood. FSH is produced by the pituitary gland, which is a pea-sized structure in the brain, in both men and women.

Women
FSH triggers your ovaries to develop follicles, which are fluid-filled sacs that contain immature eggs (oocytes). It also helps regulate your menstrual cycle.

High FSH levels may indicate PCOS, primary ovarian insufficiency (POI), an ovarian tumour, or Turner syndrome (a genetic disorder that impacts female development and fertility). Low FSH levels may indicate issues with your pituitary gland or that your ovaries are not functioning properly.

Men
FSH stimulates testicular growth and helps regulate sperm production. High FSH levels may indicate that you have a lower sperm count, potentially due to Klinefelter syndrome (a genetic disorder that impacts male sexual development and often causes infertility). Low levels may indicate that your pituitary gland or the hypothalamus is not functioning properly, which may impact fertility.

Luteinising hormone (LH) test

This test measures the amount of luteinising hormone (LH) in the blood. Also produced by the pituitary gland in both men and women, LH works with FSH to jumpstart reproductive processes in the ovaries and testes.

Women
LH initiates ovulation, which is the process where one of your two ovaries releases a mature egg (ovum). LH also stimulates the formation of the corpus luteum, which is a temporary gland that prepares your uterus for pregnancy by producing estrogen and progesterone.

Elevated LH levels could suggest that you have PCOS, which may impact fertility. Low LH levels could mean that you are not ovulating, indicating conditions such as early menopause or hypothalamic dysfunction (when the hypothalamus, which is a small area of the brain that helps regulate the pituitary gland and nervous system, is not functioning properly).

Men
LH stimulates the Leydig cells in the testes to produce testosterone, which is essential for normal sperm production. High LH levels could suggest that your Leydig cells are not functioning properly or Klinefelter syndrome. Low LH levels could indicate that the hypothalamus is not performing, which may result in infertility.

Anti-Müllerian hormone (AMH) test

This test measures the amount of anti-müllerian hormone (AMH) in the blood. AMH is produced in the ovaries and testes. While AMH is a component of male sexual functioning, an AMH test is primarily used to evaluate female reproductive health and fertility.

Women
AMH helps to regulate the development of ovarian follicles prior to ovulation. An AMH test may be used to assess the number of eggs in your ovaries, functioning as a marker of your ovarian reserve (your ovaries’ ability to produce eggs that may be fertilised). High AMH levels may be an indicator of PCOS, while low AMH levels may be an indicator of diminished fertility due to fewer eggs being produced each month.

Estradiol (E2) test

This test measures the level of the estrogen hormone estradiol (E2) in the blood. Estradiol is produced primarily by the ovaries and testes.

Women
During the menstrual cycle, E2 causes an increase of LH, triggering ovulation. E2 also stimulates the tissue growth of reproductive organs, including the lining of the uterus (endometrium), the fallopian tubes, the vagina, and cervical glands. Low levels of E2 can indicate early menopause or fertility issues, while high levels can indicate conditions like PCOS.

Men
In men, estradiol is an important hormone for sperm production, libido, and erectile function. Combined with other hormonal imbalances, high levels of E2 may result in erectile dysfunction and infertility. Low levels of E2 point to a hormonal condition, which can also impact sexual functioning and contribute to male infertility.

Prolactin test

This test measures the amount of the hormone prolactin in the blood. Also produced in the pituitary gland, prolactin levels are typically low for men and women who are not pregnant or breastfeeding. For this reason, low levels of prolactin are usually not a cause for concern.

Women
Prolactin controls lactation in women who are pregnant or breastfeeding and plays a role in regulating ovulation. High prolactin levels (a condition called hyperprolactinemia) may indicate a thyroid issue, PCOS, or a prolactinoma (a tumor that is typically not cancerous but can impact the production of hormones).

Men
Prolactin is important for libido and the ability to get an erection. High levels of prolactin may indicate, among other things, problems with the thyroid or the presence of a prolactinoma.

Progesterone test

This test evaluates the amount of the hormone progesterone in the blood.

Women
In women, progesterone is mainly produced by the corpus luteum. Progesterone prepares the uterus for a fertilised egg by prompting the tissue that lines the inside of the uterus (endometrial tissue) to thicken.

While high levels of progesterone are typically not a cause for concern, in some cases, they may indicate an issue with the adrenal glands or ovarian cysts. Low levels of progesterone may mean that you are not ovulating normally, which makes it harder to get pregnant.

Men
In men, progesterone is produced in the adrenal glands, which are located on top of the kidneys, and the testicles. Progesterone acts as a precursor to testosterone and helps maintain a balance between estrogens and testosterone. Since progesterone is involved in the regulation of other hormones, abnormal levels may impact libido, sperm production, and erectile functioning.

Thyroid-stimulating hormone (TSH) test

This test evaluates how well your thyroid is functioning by measuring the level of thyroid stimulating hormone (TSH) in the blood. TSH is a hormone produced by the pituitary gland that helps regulate fertility in both men and women by triggering the production of the two thyroid hormones. Produced by the thyroid, a small gland located at the front of the neck, thyroid hormones are critical to all major processes in the body.

Women
Among other things, thyroid hormones are responsible for regulating the function and development of reproductive tissues in the ovaries and uterus. Additionally, they interact with other hormones and help maintain balance. While low levels of TSH may indicate that you have too much thyroid hormone (hyperthyroidism), high levels indicate that you have too little (hypothyroidism). Both conditions may impact your reproductive cycle and fertility.

Men
In the male reproductive system, thyroid hormones impact the development of the testes and contribute to the production of sperm (also known as spermatogenesis). Abnormal levels of TSH may indicate an imbalance in your thyroid hormone, which can cause issues with sperm production and function.

Testosterone test

This test measures the level of the hormone testosterone in the blood. Important for both men and women, testosterone is produced in the testes, ovaries, and adrenal glands.

Women
In women, testosterone is an important hormone for ovarian functioning and bone strength. High testosterone levels may indicate PCOS, which can impact fertility. Low levels may indicate that the hypothalamus, pituitary gland, or adrenal glands are not functioning normally.

Men
As the primary male sex hormone, testosterone is responsible for male sexual development, the production of sperm, and fertility. An imbalance in testosterone levels can cause infertility by decreasing sperm production and impacting how well sperm move (motility).

Lower levels may indicate a problem with the testes, abnormal functioning of the pituitary gland or hypothalamus, or a genetic disease. While less common, high levels may indicate the presence of an adrenal or testicular tumor (which are typically noncancerous) or the overuse of anabolic steroids .

Sex hormone binding globulin (SHBG) test

This test measures the levels of sex hormone binding globulin (SHBG) in the blood. An SHBG test may be used following a testosterone test to evaluate potential causes of decreased libido, erectile disfunction (men), and infertility.

A protein that is mainly produced by the liver in men and women, SHBG is responsible for regulating the amount of three sex hormones: testosterone, estradiol (E2), and dihydrotestosterone (DHT). SHBG transports these hormones in an inactive form to their final destination and releases them. Once they are released, these sex hormones are free to stimulate other processes.

Abnormal levels of SHBG may result in an excess or lack of other sex hormones. While a high level of SHBG may cause a shortage of sex hormones that are free to act on the tissues and organs, a low level may cause an abundance. In both cases, it may produce a hormonal imbalance, impacting fertility and reproductive functioning.

Women
In women, high levels of SHBG may be related to a variety of issues, including: liver disease, an overly active thyroid (hyperthyroidism), anorexia nervosa, elevated levels of prolactin (hyperprolactinaemia), and low levels of testosterone. A high SHBG level may also be impacted by the use of estrogen medications.

Low SHBG levels may indicate PCOS, an underactive thyroid (hypothyroidism), steroid overuse, type 2 diabetes, high testosterone levels, and issues with the adrenal glands.

Men
In men, high levels of SHBG may also indicate liver disease, hyperthyroidism, eating disorders, hyperprolactinaemia, and low testosterone levels. Low SHBG levels may indicate an underactive thyroid, steroid overuse, type 2 diabetes, or issues with the adrenal glands.

Dehydroepiandrosterone sulfate (DHEAS) test

This test measures the amount of the hormone dehydroepiandrosterone sulfate (DHEAS) in the blood. Produced primarily by the adrenal glands, and to a lesser extent by the testes and ovaries, DHEAS is a hormone that your body converts into two male sex hormones (testosterone and androstenedione) and estrogen. DHEAS is important for fertility, reproductive functioning, and male sexual development.

In the event that you have high or low levels of these hormones, your fertility specialist may do a DHEAS test to evaluate whether your adrenal glands are functioning, to assess your primary sex organs (testes or ovaries), or to detect adrenal tumours. This test will usually be done after other sex hormone tests and potentially in combination with other tests, such as an SHBG test.

Women
In women, elevated levels of DHEAS may cause hyperandrogenism, a condition where the female body has an excessive amount of male sex hormones (also known as androgens). This may cause irregular menstrual periods, excessive hair growth (hirutism), acne, hair loss (alopecia) and the development of male characteristics (virilization). Hyperandrogenism is a defining feature of PCOS.

In addition to hyperandrogenism and PCOS, high DHEAS levels may indicate issues with the adrenal glands or ovarian cancer. Low levels of DHEAS may indicate Addison’s Disease or a tumor in the pituitary gland.

Men
Despite the fact that men with abnormally high levels of DHEAS may not show symptoms, it can still cause a variety of issues for reproductive functioning and fertility. High levels of DHEAS may indicate issues with the adrenal glands, while low levels of DHEAS may indicate Addison’s Disease or a tumor in the pituitary gland.

The process of fertility blood testing

The first step of going through hormone blood tests is making an initial consulation with a fertility specialist. For your initial fertility consultation, you will have a consultation at the clinic (30-45 min). During the consultation, your doctor may ask you and your partner about:

  • Your medical history and lifestyle
  • Your symptoms (such as an irregular menstrual cycle or reduced sexual functioning)
  • Medications, vitamins, or supplements that you are taking

Following your discussion with the doctor, you will book a second appointment to have your blood drawn and give a urine sample. In order to gain further insight into fertility-related issues, your doctor may recommend additional supportive tests, such as a physical exam, ultrasound, or a semen analysis.

Preparation

There are a couple of steps that you should take to prepare for the blood test in your initial consultation:

  • Inform your doctor about any medications, vitamins, or supplements that you are taking. Certain medications may impact your test results or create a risk for complications, so it is important to communicate with your fertility specialist.
  • Keep track of your menstrual cycle (women). Some tests, such as an FSH test, need to be taken at a particular time in your cycle to accurately measure hormonal levels. For this reason, you should inform your fertility specialist of where you are in your menstrual cycle before the appointment to have your blood tested.

Blood test

A medical professional will use a small needle to draw your blood. Having your blood drawn takes only a few minutes, and there are minimal restrictions or side effects to be concerned. You may experience minor bruising at the site of the blood draw due to disruption of capillaries near where the needle was inserted. This should resolve within days.

After completing your test, you will make an appointment to go over the test results with your fertility specialist and discuss additional testing or treatment options.

Test results and follow-up

Your test results should typically be available within one week of the test.

It is important to remember that your results alone do not confirm or exclude causes of infertility. In your follow-up appointment at the fertility clinic, your fertility specialist will go over your report in detail and provide guidance for subsequent assessments and fertility treatment options.

Takeaway

Fertility blood testing is a critical step in determining potential causes of infertility and helping couples or individuals pursue treatment options that could potentially improve fertility outcomes. By having a fertility blood test, you and your fertility specialist can gain important information that will allow you to make informed decisions about treatment and care.

While making your appointment, you should inform your doctor about any medications, vitamins, or supplements that you are taking. If you are a woman, you should also share where you are in your menstrual cycle, as this may impact when your blood will be drawn. Your blood test will only take a few minutes, and the results will typically be available within a week. After receiving the results, you will have a follow-up appointment with your fertility specialist to discuss additional testing or treatment options.

Fertility tests are not a one-size-fits-all approach, and the presence or absence of certain fertility markers does not always indicate fertility issues. By combining various tests with discussions of your medical history and lifestyle, your fertility specialist can provide you with the most comprehensive care.

Whether you are taking your first steps to starting a family or in the middle of your journey, our fertility specialists can guide you through fertility testing and find the most fitting fertility treatments.