Ovulation Induction – Dr Gary Swift Fertility Clinic
Ovulation induction is a technique using medications to induce or enhance egg (oocyte) development in the ovary. There are 2 main techniques used, the first is used for women who are not ovulating spontaneously (irregular or infrequent menstruation). In such cases, the aim is to stimulate the release of one egg a month. This is most easily done by prescribing fertility pills. At the Dr Gary Swift clinic, the options for ovulation induction are Clomiphene tablets in a dose from 25 to 200mg taken from day 2-6 of a cycle (with the first day of a period as day 1). The aim is to induce the formation of one follicle. We accept 2 but in Australia we would cancel a cycle if 3 or more follicles developed to avoid multiple pregnancy. The risk of twins on clomiphene is 1:20 compared to the background risk naturally of 1:80 (triplets 1:1000 cc 1:6400 naturally). If this medication is not effective, then injections of a small dose of gonadotropins may be necessary.
In the second situation, FSH induction of ovulation (gonadotrophin) is used for failed Clomiphene or with timed intrauterine insemination if unexplained infertility or her partner has mild male-factor infertility. In such a case, the aim of ovulation induction is to stimulate the production of 1 or 2 dominant follicles containing eggs to be released. This treatment is combined with intra uterine insemination (IUI) to bring the sperm closer to the egg. It is more intrusive but more effective with success rates 10-15% per cycle additive for 4 cycles. However, success rates fall significantly after the 4th cycle so at this stage a couple would move to IVF as other causes for infertility would be more likely. Under the care of Dr Gary Swift we may track cycles with ultrasound when necessary and monitor hormone levels with drug tests to make sure stimulation results are adequate but not excessive.
Once the leading follicle(s) reaches 18 mm in diameter, the egg is considered mature and ready for ovulation. The different drugs used for ovarian stimulation are:
Clomiphene Citrate tablets (Clomid® or Serophene®)
FSH injections (Gonal F® or Puregon®)
hCG or Ovidrel® injections
The dose of FSH and other hormones is carefully controlled. The effect of these hormones is carefully monitored. Your IVF doctor will carefully monitor your follicles with ultrasound. The need for further monitoring will be determined by a woman’s individual response and may require blood tests and ultrasound every other day until the follicles reach 18-20mm in diameter, large enough to contain a mature egg.