Almost 1 in 10 American women of reproductive age have a problem falling pregnant and carrying the baby to term. Among couples who are experiencing problems in conceiving a baby, 40% of cases are due to male infertility. Globally, infertility is one the rise in most developed nations. There are a number of difference reasons for infertility but most causes either directly or indirectly affect the hormones that control fertility.
What are fertility hormones?
The term fertility hormones refers to male and female sex hormones that play an important role in reproduction. Problems with these hormones or the glands that secrete it are among the more common causes of infertility in males and females. Therefore some fertility treatments require the administration of these hormones to help increase the chance of conceiving.
It is important to understand that these fertility hormones are central to the male and female sexual development and functioning. In other words most of these hormones are also responsible for the physical characteristics that make men and women different. For example, testosterone which is the main male sex hormone is also responsible for facial hair growth whereas estrogen in women plays a part in breast size and development.
Therefore even when fertility is not a concern, these hormones are necessary for normal development and functioning especially after puberty.
Male Fertility Hormones
The male sex hormones are known as androgens. It is important to understand that these hormones are also present in females but at much lower levels than it is in males. There are several hormones including testosterone, 5-alpha-dihydrotestosterone (DHT), androstanediol, androstenedione, dehydroepiandrosterone and androsterone. From all of these hormones, testosterone is the most significant.
Testosterone is produced by the Leydig cells in the testicles of males. Small amounts of testosterone are also produced by the ovaries and adrenal glands in females. Testosterone levels in males fluctuate. The normal range is within 300 ng/dL and 800 ng/dL.
Androgens have a host of different effects on the body. With regards to fertility, testosterone is responsible for stimulating sperm cell production in the testes. It is also responsible for the secondary male characteristics such as hair growth on the face and body and the development of the adam apple. In addition, androgens also reduce fat deposition and increase muscle mass.
The signs and symptoms of low testosterone levels are not always overt and can often be missed for long periods of time. The presentation also depends on whether the low levels arise in fetal life, childhood or adulthood. With regards to symptoms in men, it may present as:
- Loss of body hair (chest, scalp an face)
- Erectile dysfunction
- Decrease in genital size
- Loss of libido
Read more on low male hormones.
Female Fertility Hormones
There are two groups of female sex hormones – the estrogens and the progestogens. The estrogens comprise estradiol, estriol and estrone. Estradiol is considered the most important of these hormones. Among the progestogens, the most abundant is progesterone. Broadly, these hormones are just referred to as estrogen and progesterone.
Read more on female hormones.
The follicles in the ovaries produce estrogen, progesterone and small quantities of testosterone in females. In addition, progesterone and testosterone can also be converted into estrogen. Fat tissue is also able to produce small quantities of estrogen. The Leydig cells and germ cells in the male body also produces estrogen but in much lower quantities than it is in females.
As with testosterone, estrogen plays a role in the secondary sexual characteristics in the female body, such as breast enlargement. Higher levels of estrogen are also necessary for pregnancy and one type of estogen, estriol, is also produced by the placenta. Progesterone and estrogen also contribute to various other functions including ovulation, increased fat deposition, reduced bone resorption and fluctuations of these hormones are responsible for menstruation.
The female fertility hormones fluctuate during the course of the menstrual cycle, when pregnant and during menopause. Some of the signs and symptoms of low fertility hormones in adult females include:
- Difficulty falling pregnant
- Loss of libido
- Hot flashes
- Night sweats
- Delayed puberty
- Lack of periods
Control of Fertility Hormones
Very high levels of the fertility hormones can cause a range of different disorders and diseases in the body. Similarly very low levels can affect reproductive function and contribute to a host of medical problems. Therefore the body has to regulate the level of fertility hormones on an ongoing basis. This is achieved by other glands that lie a distance from the reproductive organs and the hormones that these glands secreted.
The hypothalamus is one part of the brain that is constantly monitoring the level of fertility hormones in the bloodstream. It has a negative feedback mechanism meaning that if the fertility hormone levels are normal to high then the hypothalamus secretes less or none of its hormone known as gonadotropin-releasing hormone (GnRH). This hormone acts on the pituitary gland that sits at the base of the brain.
The pituitary gland in turn secretes two hormones known as follicle-stimulating hormone (FSH) and luteinizing hormone (LH). In females, FSH and LH partly contributes to the release of an egg cell from the ovaries (ovulation) and to the production of estrogen and progesterone by the ovaries. In males, FSH and LH partly contribute to sperm formation and the production of testosterone by the testes.
How To Increase Fertility Hormones?
There are a number of methods to increase the fertility hormones. In the context of infertility, this is only considered where the fertility hormones are low and identified as a cause of difficulty in conceiving. This includes:
- Synthetic hormones that are manufactured in a laboratory.
- Bioidentical hormones extracted from animals or plants.
- Hormones that affect the sectrion of controlling hormones like GnRH, FSH or LH.
These hormones are administered in the form of pills or injections. Sometimes nutritional supplements are also prescribed as these nutrients may be needed in the production of certain hormones or help with its functioning. Studies have also shown that maintaining a normal body weight, controlling blood glucose levels and exercise can also play a role in regulating the fertillity hormone levels in certain conditions.