|
|
When the pituitary doesn't release FSH and LH or releases them in an improper balance, HMG (Human Menopausal Gonadotropin) substitutes for them and acts directly on the ovaries to stimulate the development of the follicle. HMG is a natural product containing both human FSH and LH, 75 or 150 international units of each per ampule. This material is extracted from the urine of postmenopausal women, carefully purified and then freeze dried in sterile glass ampules where it is sealed until use.
Recently, biotechnology (using recombinant DNA) has been used to produce synthetic FSH. Chinese Hamster ovary cells have been genetically engineered, so that they are capable of producing, or "expressing", commercial quantities of FSH in bioreactors. This is an exciting advance, and means that companies can now manufacture large quantities of pure hormone, without risk of contamination. However, these products have been priced exorbitantly, which makes them unaffordable for many patients. While they are as good as the conventional urinary gonadotropins, they are no better - and may actually be less cost-effective, because they are so expensive. Hopefully, increasing competition may mean that these hormones will be inexpensively available in the future. However, this is likely to take a few years more.
Dose: Most women need to take daily injections of HMG over a period of several days each month. The exact number of days will be determined by the physician through monitoring your response to the injections. HMG therapy usually begins on day 3 to day 5 of the menstrual cycle. If the patient is not menstruating, the injections may be started at any time. Every patient is different in her response to HMG and even the same patient may not respond in the same way from one cycle to another. Therefore, the dosage of HMG required to produce maturation of the follicle must be individualized for each patient. This factor is the key to success with these injections. It is recommended that the lowest possible dose consistent with good results be used. HMG cannot be taken orally because it is a protein and would be digested in the stomach. It is given by intramuscular injections into the buttocks or the thighs. Recombinant FSH can be administered subcutaneously, and this is much more convenient for patients, as they can take their own injections.
Side effects: Many women worry that if they take HMG, this will cause them to "run out of eggs" because the HMG stimulates the maturation of a large number of eggs. However, remember that every month, 30-40 eggs start to mature. In the natural cycle, only one matures, while the rest die. HMG helps to rescue the eggs which would otherwise have died, so it does not cause you to lose or waste your precious eggs!
HMG is a potent drug with the potential to cause side effects. The most common side effect with HMG relate to overstimulation of the ovary and every effort is made to avoid this by monitoring the response to HMG carefully. Mild to moderate uncomplicated ovarian enlargement, sometimes accompanied by abdominal distension and/or abdominal pain occurs in about 20% of those treated with HMG and HCG. This generally is reversed without treatment within 2 to 3 weeks.
A potentially serious side effect of HMG is the ovarian hyperstimulation syndrome (OHSS) which is characterized by enlargement of the ovary and an accumulation of fluid in the abdomen. This fluid can also accumulate around the lungs and may cause breathing difficulties. If the ovary ruptures, blood can accumulate in the abdominal cavity, as well. The fluid imbalance can also affect blood clotting and, in rare cases, could be life threatening. Fortunately, the hyperstimulation syndrome is not common, occurring in about 1% to 3% of patients. Treatment consists of bed rest and careful monitoring of fluid levels.
Another risk with HMG therapy is when it is too successful at producing eggs - thus resulting in mutiple pregnancies, with the risks associated with these. Of the pregnancies following therapy with HMG most (80%) will be single births. The multiple gestation rate is approximately 20%, the majority of which have been twins. About 5% of the total pregnancies result in three or more conceptuses. Despite careful monitoring, multiple gestations cannot be altogether avoided.
Other adverse reactions that have been reported with HMG therapy are mild and include allergic sensitivity, pain, rash, swelling at the injection site. Many women are worried that the HMG will cause them to put on weight. However, remember that the HMG is a "natural" hormone. It does not affect your caloric balance, and does not cause you to become fat ! However, many women do restrict their physical activity when taking infertility treatment. This restriction causes them to burn fewer calories, and this may lead to weight gain which they then attribute mistakenly to the HMG injections. HMG may cause fluid retention, but this is temporary, and HMG injections have no long-term side-effects.
© Dr. Aniruddha Malpani and Dr. Anjali Malpani www.drmalpani.com
Credits: How to Have a Baby: Overcoming Infertility
_2.jpg)
