Gonadotropins (Menopur, Puregon, Gonal F, Fostimon, Merional) are natural hormones used to stimulate the ovaries in the expectation of prompting the growth of several egg cells in the period of 8 or more days. All medications used in the process of stimulation contain FSH – a hormone which causes the growth of ovarian follicles (containing egg cells). Some of these medications also contain LH or other substances the effect of which is similar to that of LH. LH (luteinizing hormone) is a hormone which, together with FSH, causes the increase in the level of estrogens and the growth of follicles.
In the stimulation process, recombinant LH (Luveris) or alternatively small amounts of hCG may also be given. The medications are usually administered in the form of subcutaneous or intramuscular injections. The proper dosing of the medications and setting the time point for ovum pick-up requires the monitoring of the ovarian response to stimulation; to this aim, blood samples are collected for laboratory testing (estradiol) and ultrasound examinations are carried out using a vaginal probe.
Side effects of gonadotropins
The administration of the medications may cause site reactions such as edema, bruising, skin redness. Very uncommonly, allergic reactions may occur. Gonadotropins are given with the aim to achieve the maturation of many follicles, which leads to the enlargement of the ovaries. The patient may feel swollen (flatulent) and experience general discomfort. Approximately 2% of patients may experience ovarian hyperstimulation syndrome (OHSS). Other side effects of gonadotropins may include the feeling of tiredness, headache, increased body weight, mood changes, nausea and venous thrombosis.
Despite the initial qualification and stimulation conducted under medical supervision, the ovarian response to the medications may be insufficient; few follicles may develop or – very rarely – the ovaries may not respond to the stimulation at all, with the result that only the small number of egg cells will be picked up, or even that the stimulation will be discontinued before ovum pick-up.