Gonadotropin therapy is a fertility treatment that uses injectable hormones to stimulate the ovaries. These medications are composed of Follicle-Stimulating Hormone (FSH) and Luteinizing Hormone (LH). In a natural menstrual cycle, these hormones are released by the pituitary gland to encourage the development and release of a single mature egg.
This therapy administers these hormones, often at higher concentrations, to prompt the ovaries to produce one or more mature follicles. Follicles are the small sacs within the ovaries that contain developing eggs. Modern preparations are either highly purified from natural sources or created in a laboratory using recombinant DNA technology.
Medical Uses for Gonadotropin Therapy
Gonadotropin therapy is prescribed for several specific causes of infertility in women and men. For women, a primary use is to treat anovulation (the failure to ovulate), which is common in individuals with Polycystic Ovary Syndrome (PCOS) where hormonal imbalances disrupt egg development. It is also an option for women who do not respond to oral fertility medications like clomiphene citrate.
The therapy is a component of assisted reproductive technologies (ART). During an In Vitro Fertilization (IVF) cycle, gonadotropins are used for controlled ovarian stimulation to develop multiple mature eggs for retrieval. When combined with Intrauterine Insemination (IUI), the goal is to produce a few mature eggs to increase the probability of fertilization when sperm is placed in the uterus. This approach is also applied to cases of unexplained infertility.
In men, this therapy can address infertility from hormonal deficiencies. It is used to treat hypogonadotropic hypogonadism, a condition where the pituitary gland does not produce sufficient amounts of LH and FSH. Administering gonadotropins can stimulate the testes to produce testosterone and improve sperm production (spermatogenesis).
The Treatment Process
A cycle of gonadotropin therapy begins on the second or third day of the menstrual cycle with a baseline ultrasound and blood tests. These initial assessments confirm there are no ovarian cysts that could interfere with treatment and establish baseline hormone levels. The patient then begins self-administering the medication through subcutaneous injections.
Close monitoring is a feature of this treatment. Throughout the injection phase, which lasts about eight to ten days, the patient has several appointments for transvaginal ultrasounds and blood work. Ultrasounds allow a specialist to visually track the number and size of the developing follicles. Blood tests measure the level of estradiol, an estrogen produced by the growing follicles, which helps in adjusting medication dosage.
Once the lead follicles have reached a mature size, a final injection of human chorionic gonadotropin (hCG) is administered. This “trigger shot” prompts the final maturation of the eggs and sets a precise timeline for ovulation, which occurs about 36 hours later. This timing is used to schedule either IUI or the egg retrieval procedure for IVF.
Potential Side Effects and Complications
Patients may experience a range of side effects during therapy. Milder effects are temporary and can include:
- Bloating
- Headaches
- Mood swings
- Soreness or bruising at the injection site
The hormonal stimulation can also lead to benign ovarian cysts that usually disappear on their own.
A more significant complication is Ovarian Hyperstimulation Syndrome (OHSS), where the ovaries respond excessively to the medication, leading to fluid buildup and discomfort. Severe cases can be serious, but the risk is minimized through the intensive monitoring of follicle growth and hormone levels, which allows for dose adjustments.
This therapy also increases the likelihood of multiple pregnancies, such as twins or triplets. Because the treatment aims to produce more than one mature egg, the chance of multiple embryos implanting is higher. Careful management and counseling on the risks associated with multiple births are part of the process.
Factors Influencing Treatment Success
The success of gonadotropin therapy depends on a variety of individual factors. A woman’s age is a primary determinant, as the number and quality of her eggs decline over time, which can affect the response to treatment and the likelihood of a viable pregnancy. The underlying cause of infertility also plays a large role in the potential for success.
The specific protocol used influences the outcome. For example, combining gonadotropin therapy with IUI results in different success rates than when it is used as part of a more complex IVF cycle. The quality of the sperm is another consideration, as male factor infertility can impact fertilization even when ovulation is successfully induced.
General lifestyle factors, such as weight and smoking, can also affect reproductive health and the body’s response to treatment. The cumulative pregnancy rate can increase over several cycles of treatment, but success is highly individualized based on these biological and procedural variables.