Getting Pregnant With PCOS: Ovulation Induction With Follicle Stimulating Hormone – FSH
We use FSH ovulation induction as the next step in women with PCOS where the tablet Clomid has failed to cause ovulation- we call this Clomid resistant and occurs in 20 % of women with PCOS, or where no pregnancy has occurred despite several cycles of successful ovulation with clomid, usually no more than 6 cycles.
Follicle stimulating hormone FSH is a natural hormone produced and secreted by the pituitary gland in your brain. It plays an important role in fertility by stimulating the growth and development of follicles in the ovaries.
It has been used since the 1960s to help induce follicle growth and ovulation. Today it is made in a purified injectable form to be used for helping ovulation induction treatment and In-vitro Fertilization (IVF) treatment. See figure below of FSH injection pen.
Ovulation induction with FSH injections needs close supervision by your doctor in a specialized fertility clinic, as there are some risks with using this treatment option.
The main risks are
- Multiple pregnancy. The possibility of the pregnancy being twins is in the order of 6-10%, so you would need to have careful monitoring with blood tests and pelvic ultrasound scans in a fertility clinic.
- A rare but serious complication called Ovarian Hyper stimulation Syndrome. (also called OHSS). This occurs in <1% of cycles.(see ovarian hyper stimulation syndrome in the fertility treatment section and clinical notes section)
Ovulation Induction Treatment Timeline
- Treatment typically begins on the 2nd or 3rd day of your menstrual cycle. You start daily FSH injections. These injections look a bit like a pen (see the Puregon R pen above) and have a very small needle that you place just under your skin ( sub-cuticular). Each person will be slightly different in their ovarian response but it generally takes about 7 – 14 days of daily injections to induce follicle growth and eventually ovulation.
- Starting with the lowest FSH dose of 37.5 IU- 50 IU you will be taught how to give yourself an injection into the skin of your belly. My patients have found it reasonably easy, but if you do have trouble the clinic nurses or your doctor would be able to do this for you.
- The response from your ovaries needs to be monitored closely and regularly to make sure only one egg is growing, and that you are not developing ovarian hyper-stimulation syndrome (OHSS). We monitor you using blood tests about every 3rd day looking at the rising blood level of the hormone estrogen and ultrasound scanning looking at the growth of the leading follicle. Depending on what the results show the dose of the FSH injection will be individualized. That is – you might need to have the dose increased, reduced or stopped.
- An ultrasound provides a visual assessment of your follicle growth and development- therefore it can tell if more than one follicle is present and therefore the possibility of ovulating more than one egg. Follicle growth occurs at a rate of 1-3mm/day
- When the dominant follicle reaches a size of 18mm or greater on ultrasound and your blood estrogen level is within the appropriate pre-ovulation range of 500- 1500 pg/ml a special one off trigger injection called Human Chorionic Gonadotrophin (HCG) is given intra-muscular.
- HCG is an injectable hormone called human chorionic gonadotrophin. This hormone stimulates ovulation
- When HCG is given ovulation typically occurs 36 – 38 hours later. Sexual intercourse or intra-uterine insemination can then be timed accordingly.
Your chance of a pregnancy is around 20% per cycle of treatment with approximately a 40-60% of chance of pregnancy after 4 cycles of treatment.
Ovulation Induction Side Effects:
All medicines can have side effects, most here are not serious. Some women may experience no effects and others can display one or two.
Side effects to ovulation induction can be headaches, nausea, bruising or rash at injection site, mood swings, mild abdominal discomfort and some breast tenderness.
OHSS (ovarian hyper-stimulation syndrome) and a blood clot are major but rare complications. Multiple pregnancy chances are about 5-10%.
I know it sounds odd saying that a multiple pregnancy should be a downside. Many of my patients tell me they would be delighted to have twins – then their family would be complete in one go. However twins and more so triplet pregnancy comes with increased risk to both mother and babies, poorer outcomes and an increased chances of cerebral palsy.
But for you the goal is to help you achieve a pregnancy safely, the result being a healthy mother, a healthy pregnancy and a healthy child.