Gonadotropins are protein hormones present in the bodies of women and men. The two principle types of gonadotropins in women are two sex hormones called Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH). FSH and LH are produced by the gonadotrope cells in the pituitary gland in the brain. In women, FSH and LH regulate the reproductive system and therefore control ovulation. A lack of these hormones can interfere with the ovulation process, making ovulation irregular or perhaps totally absent (a condition called anovulation). Therefore, a lack of gonadotropins gives rise to fertility problems. There are a number of reasons why some women’s bodies don’t produce enough gonadotropins, one of which is disease of some type in the pituitary gland. Gonadotropin-based fertility drugs are offered, in certain circumstances, to women who aren’t ovulating normally as a result of hormone deficiency.
FSH And LH
To understand how gonadotropin fertility supplements combat infertility, it’s helpful to understand how naturally-produced FSH and LH control ovulation. In a woman who is ovulating normally, FSH triggers the growth of follicles in the ovaries during the first stages of the woman’s menstrual cycle. These follicles produce and nurture the woman’s eggs. The eggs grow and develop and when an egg has reached maturity, a surge in LH levels in the woman’s body makes the ovary release the egg into the fallopian tube. The mature egg is now ready to be fertilized by sperm. If the egg is not fertilized, it is flushed out during the woman’s menstrual period at the end of her cycle.
Gonadotropin Fertility Drugs
hMG – human Menopausal Gonadotropin is made of natural gonadotropins (FSH and LH) which have been extracted from the urine of post-menopausal women and then purified. (After women go through the menopause, high levels of gonadotropins come out in their urine.)
rFSH – recombinant Human Follicle-Stimulating Hormone is a form of genetically synthesized FSH.
hCG – human Chorionic Gonadotropin contains equal amounts of FSH and LH. This drug has an effect similar to that of LH.
How Gonadotropins Work
Gonadotropin-based fertility supplements imitate the function of FSH and LH in stimulating ovulation. The patient is given daily injections of hMG and rFSH for approximately 12 days. The gonadotropin drugs stimulate the growth of follicles in the ovary. These follicles will (hopefully) produce mature eggs. The patient is closely monitored and then, when the eggs are fully mature and ready to be fertilized, an injection of hCG is given. Just like the natural LH surge, the hCG injection triggers the release of the egg (or eggs) from the ovaries. The next step is fertilization, which may be achieved through timed intercourse, or Assisted Reproductive Technologies such as IUI or IVF.
Who Is A Candidate?
Gonadotropin fertility treatment is not suitable for all women suffering from fertility problems. Suitable candidates for gonadotropin-based fertility drugs are:
- Women who are not ovulating because they lack sex hormones (the gonadotropins FSG and LH) or have low estrogen levels in their bodies.
- Women who have a hormone-related ovulation disorder, against which clomiphene treatment has failed.
- Women suffering from Polycystic Ovarian Syndrome (PCOS), for whom clomiphene treatment has failed.
- Women undergoing fertility treatment with Intrauterine Insemination (IUI) or In-Vitro Fertilization (IVF). Such women may need gonadotropin fertility treatment prior having their eggs fertilized, to help them produce the eggs in the first place.
Gonadotropin fertility treatment helps 60 % of patients to get pregnant; however, 35 % of these pregnancies end in miscarriage. This miscarriage rate is higher than the rate among women who conceive naturally.
In addition to a higher chance of miscarriage, other risks of gonadotropin fertility supplements include:
- Multiple pregnancy (the possibility of having twins, triplets, or more). Gonadotropin supplements cause the ovaries to produce more than one egg per treatment cycle, which increases the chance of more than one egg being fertilized and growing into a baby. Pregnancy with multiple babies is riskier for both the mother and her babies.
- Ovarian Hyper Stimulation Syndrome (OHSS), which is often very treatable but in some cases can be life-threatening. If treatment with gonadotropins is properly monitored, the patient is said to have a less than a 1 % chance of developing OHSS.
- Headache and abdominal pain.