Ovulation induction aims to produce one or two mature eggs in women who do not ovulate regularly, while ovarian stimulation for IVF aims to grow several eggs in a controlled way. The main medications are described below.
Letrozole
Letrozole is a tablet that briefly lowers estrogen production, prompting the brain to release more FSH. It is now the first-line medication for ovulation induction in polycystic ovary syndrome (PCOS), with higher live birth rates than clomiphene and less negative effect on the uterine lining and cervical mucus.
Clomiphene citrate (Clomid)
Clomiphene blocks estrogen receptors in the brain, so the brain senses low estrogen and responds by raising FSH and LH, which stimulates follicle growth. It is taken as tablets. It can thin the uterine lining and make cervical mucus less favourable to sperm, and may cause hot flushes, headaches and visual disturbances (which require stopping the drug). Like other stimulation drugs, it increases the chance of twins, and occasionally ovarian cysts.
Tamoxifen
Tamoxifen works in a similar way to clomiphene and is occasionally used as an alternative.
Gonadotropin injections (FSH and LH)
These injections contain measured doses of FSH, with or without LH. They are available as human menopausal gonadotropin (hMG), purified urinary FSH, and recombinant FSH made by biotechnology. They are used for ovulation induction when tablets fail, for IUI cycles and for IVF stimulation. Doses are tailored to age, AMH and antral follicle count, and response is monitored by ultrasound, because the main risks are multiple pregnancy and ovarian hyperstimulation syndrome (OHSS).
Medications to lower prolactin
When raised prolactin is the cause of absent ovulation, cabergoline (once or twice weekly, with fewer side effects) or bromocriptine (daily, more often causes nausea) usually restores ovulation.
GnRH agonists
GnRH agonists first stimulate the pituitary and then switch off its release of FSH and LH. They are used to shrink fibroids or endometriosis, and in some IVF protocols (“long protocol”) to prevent premature ovulation while gonadotropins stimulate the ovaries. A single dose of a GnRH agonist can also be used as the ovulation trigger, which greatly reduces the risk of OHSS.
GnRH antagonists
GnRH antagonists block the pituitary immediately. Started a few days into stimulation, they prevent premature ovulation. The antagonist protocol is now the most widely used IVF protocol because it is shorter, needs fewer injections and has a lower risk of OHSS.
The trigger injection (hCG)
hCG has a structure similar to LH. Once the follicles reach the right size, it is given to trigger final egg maturation, and ovulation or egg collection is timed precisely around it (egg collection is usually about 36 hours later).
International Guidelines
In line with global standards, Dr. Sabry follows the latest recommendations from the American Society for Reproductive Medicine (ASRM), European Society of Human Reproduction and Embryology (ESHRE), and Royal College of Obstetricians and Gynaecologists (RCOG). Thus, patients receive care that is safe, ethical, and evidence-based.
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Why Choose Dr. Ashraf Sabry?
Dr. Ashraf Sabry, consultant in obstetrics, gynecology, fertility, and aesthetic gynecology, is recognized among the best OBGYN and fertility specialists in Cairo. With over 20 years of experience, he combines science and compassion to provide world-class care. Book your appointment through the contact page, WhatsApp, or call +201022224442.