Getting pregnant is more complicated than you might think. The chance of getting pregnant in each cycle is around 25% , even without fertility problems. Getting pregnant involves an intricate balance of your fertility hormones.

Oestrogen, Progesterone, LH, and FSH

The right hormones must wax and wane at just the right time. If you don’t pay close attention to your menstrual cycle and monitor your ovulation, you might lose your fertility window and take months, even years, to get pregnant. Hormones are the chemical messengers of our body that control every aspect, big and small, from fertility to appetite. Changes in hormone levels can have a devastating effect on the body’s normal functioning. Fluctuations of hormones that control appetite or mood are quite easy to spot. However, if there is an imbalance in the fertility hormones, such as the Luteinizing Hormone (LH) , it cannot be easy to trace, especially if you don’t know what to look for. Your menstrual cycle and, hence, your fertility is controlled by four major hormones: estrogen, luteinising hormone (LH), Progesterone , and follicle-stimulating hormone (FSH). A normal menstrual cycle involves a phasic rise and fall in levels of these four hormones. If there is an imbalance of even a single hormone, the whole menstrual cycle can be thrown off course. An erratic, irregular menstrual cycle can pose the biggest hurdle in getting pregnant. Getting the levels of these hormones checked every day is not a feasible alternative. You can track some physical symptoms that give you valuable insights into your periods and fertility window.

Important fertility hormones: Oestrogen, Progesterone, LH, and FSH

What is oestrogen & what does oestrogen do?

Oestrogen is a key fertility hormone produced within the ovarian follicles in the ovaries . Maintaining appropriate levels of this hormone is crucial for a healthy menstrual cycle and fertility. Beyond its pivotal role in reproductive health, oestrogen is also instrumental in the formation of bones, the emergence of secondary sexual traits, and the regulation of cholesterol in the body.

What is an ideal oestrogen level?

The amount of oestrogen secreted in your body changes with your age. The two most common forms of oestrogen are estrone and estradiol. Both these forms are responsible for fertility. The levels of these hormones vary in women depending on their age group.

• • Prepubescent girls have almost undetectable levels of both hormones in their blood. Estradiol and estrone hover between 20 pg/ml and 29 pg/ml, respectively.
  • Pubescent girls also have a trace amount of these hormones. Estradiol and estrone levels can range between 10 and 200 pg/ml.
  • Adult, menstruating women can have about 17-200 pg/ml of estrone and 15-350 pg/ml of estradiol.
  • Postmenopausal women have very little of both these forms of oestrogen. The estrone level is between 7 and 40 pg/ml, while the estradiol level is less than 10 pg/ml. An abrupt and abnormal change in the estrogen level can adversely affect your menstrual cycle, including fertility and ovulation. Low estrogen levels during and after menopause are responsible for menopause-related symptoms such as hot flashes and night sweats.

What does low oestrogen mean, and how do you detect it?

A decline in estrogen levels can seriously hamper your chances of getting pregnant. If your body produces inadequate oestrogen, it can cause anovulatory cycles where there is irregular or a lack of ovulation. Low oestrogen is also a sign of some eating disorders as well. Excessive exertion in the form of heavy physical exercise and being underweight can also be one of the reasons for a low oestrogen level. Women suffering from low oestrogen levels often have irregular periods , making it very difficult to get pregnant. Here are some symptoms of low oestrogen levels:

• • Low oestrogen means a lack of vaginal lubrication. This can lead to painful sex
  • An increase in Urinary Tract Infections can also be correlated to a lower level of oestrogen
  • Frequent mood swings
  • Erratic or absence of periods
  • Hot flashes and depression
  • Frequent and unexplained headaches

What are high estrogen levels and their symptoms?

What causes high oestrogen levels? An unusually high level of oestrogen is also not a good thing. There is often an underlying medical cause for such high levels. Health conditions such as endometriosis and PCOS can cause an elevation of oestrogen in the body. PCOS causes irregular periods, while endometriosis can cause a build-up of scar tissue in the uterus. Both conditions can make your body a hostile environment for the foetus. Another reason for an elevated oestrogen level is obesity and high body fat content. As oestrogen is a fatty hormone, the more fat you have, the more oestrogen your body will produce. It is also observed that obese and overweight women stand at a higher risk of developing PCOS. Medications such as oral contraceptive pills and some antibiotics may also be responsible for elevated oestrogen levels. If you are or were on oral contraceptives, their effects on the body can last long after you have stopped using them. Some symptoms of higher levels of oestrogen include:

• Noticeable weight accumulation around the hips and thighs
• Unusual menstrual flow, either heavier or lighter than normal
• Exacerbated symptoms of premenstrual syndrome ( PMS )
• Formation of fibroids in uterine and breast tissues
• Reduced libido, sensations of fatigue, and emotional fluctuations

What is progesterone?

What does progesterone do? Progesterone is one of the most important fertility hormones. It is produced in small quantities by the adrenal glands and an insignificant amount by the remaining part of the ovarian follicles after ovulation. The structure formed in the ovaries, the remnant of the follicles, is called the corpus luteum. Progesterone is the hormone that will prepare your body to harbour the fertilised egg. It is also responsible for the proper functioning of the Fallopian tubes. Progesterone is responsible for the embryo’s implantation and is crucial for carrying the foetus to term.

What is a healthy level of progesterone?

Progesterone, a key hormone for fertility, experiences fluctuations throughout the menstrual cycle and the various stages of pregnancy. The concentration of this hormone can range from zero up to 214 ng/ml, contingent on the specific phase of the menstrual cycle. Here’s a breakdown of typical progesterone concentrations during different cycle phases:

• Pre-ovulatory phase: Less than 0.89 ng/ml
• Ovulatory phase: As high as 12 ng/ml
• Post-ovulatory phase: Ranges between 1.8 and 24 ng/ml
• First trimester of gestation (initial three months): 11 to 44 ng/ml
• Second trimester (subsequent three months): 25 to 83 ng/ml
• Third trimester (final three months): 58 to 214 ng/ml

What causes low progesterone?

Lower-than-normal levels of progesterone can be detrimental to your reproductive health. If your progesterone levels are too low but you have high estrogen levels, estrogen dominance is the condition. This condition makes it all the more difficult to get pregnant. Low progesterone can occur due to many underlying medical conditions, including PCOS . Some of the symptoms of low progesterone include the following:

• • Your LH levels can get messed up (more on that a bit later in the article)
  • You keep getting a negative ovulation test
  • There is no spike in basal body temperature
  • Irregular menstrual cycles are heavier than usual bleeding
  • A diminished sex drive
  • Hot flashes
  • You can even experience anxiety or depression
  • Progesterone levels can also cause a pregnant woman to miscarry

What does high progesterone mean?

In many cases, a high level of this fertility hormone results from a congenital disability called adrenal hyperplasia. In this medical condition, children produce higher than usual amounts of male sex hormones and a very low amount of another hormone called cortisol. Higher progesterone levels are also found in women taking oral birth control pills. Medical conditions such as endometriosis can also cause an elevation of progesterone levels in the body. One of the most concerning effects of a sustained higher amount of progesterone in your body is an increased chance of developing breast cancer . An increased progesterone level has also been associated with a reduced risk of developing ovarian cancer. A higher progesterone level can also cause a decrease in fertility by causing a low oestrogen level. This creates an imbalance between hormones and can hamper your chances of conceiving. Some of the symptoms of high progesterone levels include the following:

• • Feeling bloated
  • Feeling sluggish and sleepy
  • Dizziness
  • Increased incidences of yeast infections

What is the Luteinising hormone (LH)?

The luteinising hormone is an important fertility hormone controlling your menstrual cycle. It is responsible for releasing a matured egg from the follicles in the ovary. LH is an excellent biomarker for determining the precise time of ovulation. It is one of the most important hormones to keep track of if you are trying to conceive. The levels of LH surge during the menstrual cycle, which signals to the ovaries that it is time to release the egg. Ovulation strip tests and ovulation predictor kits ( OPK ) from Fertility2Family can help you track this LH surge and predict when you will ovulate in your cycle.

Direct Patterns of LH and FSH During Your Cycle

During the menstrual cycle, FSH and LH follow clear, predictable patterns that outline your fertile window. In the early follicular phase, FSH rises steadily to encourage the growth and maturation of ovarian follicles, setting the stage for ovulation.

As the cycle continues, increasing estrogen levels trigger a sharp LH surge. This spike usually happens 24 to 36 hours before ovulation, signalling that the egg is about to be released. While FSH supports follicle development gradually early in the cycle, the sudden rise in LH marks the opening of your fertile window for conception.

These hormone changes offer a simple guide to understanding your most fertile days. Although individual hormone levels can vary, identifying the LH surge as the trigger for ovulation connects these biological signals to your fertility timeline. Always consult healthcare professionals for personalised advice on interpreting your hormone patterns within your overall reproductive health.

• • Absence of ovulation (anovulation) or period (Amenorrhoea)
  • Early puberty in young girls
  • Early menopause in menstruating women
  • Infertility

What is Follicle-stimulating Hormone (FSH), and what Does It Do?

Follicle-stimulating hormone (FSH) is also a pituitary fertility hormone. It works with the LH to help the ovarian follicles mature. An egg released from the matured follicles is only capable of fertilisation. So, the follicles must mature properly before they release the egg. FSH also changes the composition of cervical mucus. A change in the consistency of the cervical mucus is also an excellent way of predicting your fertile window. The cervical mucus is thin, creamy, and white for most menstrual cycles. However, when you ovulate, it becomes much thicker and almost transparent, like an egg white. The body does this to let the sperm survive and reach the egg during the fertile window.

What is a healthy FSH level?

The level of this fertility hormone fluctuates with your age. It is normal to have a negligible amount of FSH (0-4.0 mIU/ml). The level significantly increases during puberty, reaching between 0.3-10.0 mIU/ml. Menstruating women have a level of FSH between 4.7 and 21.5 mIU/ml, depending on age and the menstrual cycle phase. As with LH, FSH levels increase after menopause, reaching 25.8 to 134.8 mIU/mL.

What does low FSH mean, and what are its symptoms?

A low FSH can be a roadblock to your pregnancy. Lesser FSH in the body means fewer follicles maturing and developing in your ovaries. Low FSH can be related to an issue with the pituitary gland or hypothalamus. Being extremely underweight can also harm your FSH levels. Lack of proper nutrition due to some sort of an eating disorder can cause irregular periods of a condition called hypothalamic amenorrhea. Some other symptoms of a low FSH include the following:

• • Your cervical mucus does not change its consistency throughout the cycle
  • You might experience hot flashes
  • You might also experience sleep disturbances
  • There might be significant mood swings
  • Higher rate of urinary tract infections

What does a high level of FSH mean, and what are the symptoms?

Elevated levels of FSH can result from various underlying factors. One such cause could be primary ovarian insufficiency, a condition in which the ovaries cease egg production prematurely, often before age 40. Women with primary ovarian insufficiency (POI) might get their periods, but their menstrual cycles are anovulatory because the ovaries are not functioning. POI can be a significant cause of infertility. PCOS can be another cause of elevated levels of FSH. A genetic condition called Turner’s syndrome can also result in elevated levels of FSH. People suffering from Turner’s syndrome have a genetic defect due to a missing or incomplete X chromosome. That said, an increased level of FSH is common among women who are in post-menopause.

High FSH

However, if you are younger than 40, a high FSH level might indicate that you are undergoing premature menopause. Sometimes, a higher-than-usual amount of FSH in the body might indicate ovarian cancer. Ovarian cancer is one of the most common cancers in females. Some data suggests that as many as one in 78 women stand the chance of developing ovarian cancer in their lifetime. The chances of developing ovarian cancer increase if you have mutations called BRCA1 or BRCA2. That said, the mean age of women diagnosed with ovarian cancer is around 63 years. If you’re below the typical age range, the likelihood of having ovarian cancer is generally lower. The high fatality rate of ovarian cancer is often due to late-stage diagnosis. Should you notice elevated FSH levels, it’s imperative to consult your healthcare provider promptly to eliminate the possibility of ovarian cancer. Indicators of increased FSH can include:

• • Erratic and irregular periods
  • Hot flashes and headaches
  • Infertility
  • Fewer follicles in ovaries

All four hormones are crucial for maintaining reproductive health and fertility. It is important to check the levels of these hormones throughout your cycle to monitor your fertility window. It is a common practice for doctors to suggest their patients try getting pregnant naturally for at least a year (six months if you are over 35) before they prescribe any diagnostic test. However, tracking your hormones using fertility tests and kits from Fertility2Family is wise. Keeping track can not only help you to conceive but also give you an insight into the proper functioning of your reproductive system. If you see any abnormal changes in your hormonal levels, you can report them to your doctor before it is too late.

Accurate, reliable data about your reproductive health

At Fertility2Family, we understand that the journey to parenthood is filled with complexities. That’s why we offer a range of fertility tests and kits to provide accurate, reliable data about your reproductive health. Our products are not just tools but guides that offer invaluable insights into your fertility window and hormonal balance. With our expertise, you can confidently make informed decisions and consult your healthcare provider. Trust Fertility2Family to be your reliable partner in this significant phase of life, providing you with the knowledge and resources to make your dream of starting a family a reality.

Evan kurzyp

Evan Kurzyp

Evan is the founder of Fertility2Family and is passionate about fertility education & providing affordable products to help people in their fertility journey. Evan is a qualified Registered Nurse and has expertise in guiding & managing patients through their fertility journeys.