Ovulation Induction

Ovulation Induction


It is a form of treatment used in vaccination (IUI) and all other Assisted Reproductive Treatment Methods (In Vitro Fertilization, Microinjection) in which an attempt is made to increase the chance of pregnancy by providing the development of more than one egg (Controlled Ovarian Hyperstimulation) in women who do not ovulate or who ovulate irregularly (ovulation induction) or women with ovulation (Controlled Ovarian Hyperstimulation). For this, various drugs are used that stimulate the ovulation process. These drugs are continued until the sacs (follicle) containing the eggs reach a certain size (18-20 mm), and the patient is followed up with ultrasonography and hormone (E2) monitoring while the drugs are being used. When the follicles reach a certain size, a cracking injection (hCG) is performed. After 36-40 hours after that, either sexual intercourse is recommended (timed coit) or artificial insemination (implantation, IUI) if applicable, or egg collection (OPU) for in vitro fertilization (IVF) or microinjection (ICSI) procedures.


There are various drugs used to induce ovulation in women who do not ovulate;
Clomiphene Citrate (CC) and Tamoxifen are known as selective estrogen receptor modulators. CC is the most commonly used drug and it is started at a dose of 50 mg on the 5th day of menstruation, it can be increased to 50 mg in subsequent cycles if necessary, and it is not desirable to exceed the maximum daily dose of 150 mg. In higher doses, it disrupts the development of the endometrium and causes pregnancy rates to remain low. It is possible to achieve 80% ovulation and 40% pregnancy rate in s6 months with CC, and if pregnancy is not seen after 6 cycles, other options should be used. The multiple pregnancy rate is 10%, and side effects are not common, and hot flashes are the most common complaint.


Aromatase inhibitors (Femera=letrozole, anastrozole) reduce the level of estrogen in the blood by blocking the aromatase enzyme, which enables the conversion of male hormone androgens to female hormone estrogen, thus increasing the secretion of gonadotropin (FSH/LH) from the pituitary gland by removing the suppressive effect of estrogen on the brain. However, the drug is not allowed to be used for this purpose in our country.


Insulin-sensitizing agents = Metformin is used in patients with polycystic ovaries (PCOS) at a dose of 1500 to 2000 mg per day. It can be combined with clomiphene in clomiphene-resistant cases. The use of mretformin reduces the risk of miscarriage. No harmful effects have been demonstrated with its use during pregnancy. It usually shows its effect within 2-3 months.


Gonadotropins are non-oral drugs and are used as intramuscular or subcutaneous injections. They are used alone or in combination with the above oral agents. It is generally preferred to start the treatment at a dose of 75 U on the 2nd or 3rd day of the cycle, and the dose is adjusted according to the patient’s response in the follow-ups with ultrasonography and estrogen measurement. The pregnancy rate is higher than with oral agents, but the risk of multiple pregnancies and OHSS (overstimulation of the ovaries) is equally increased.