Ovulation induction (OI)

Ovulation induction refers to the stimulation of follicular growth and ovulation through the use of medication, in order to increase the couple’s chances of conception. It is mainly indicated in women with ovulation disorders, but is also prescribed for other causes (mild male factor, unexplained infertility…). The fertility drugs can be oral (Clomiphene Citrate, Letrozole…) or injectable (Subcutaneous injections of Gonadotropins). These drugs can sometimes lead to multiple follicular growth, thus increasing the chances of multiple pregnancies (twins, triplets…).

Depending on the indication, ovulation induction can be prescribed without any additional observation, or followed by serial ultrasound monitoring to check follicular growth and ovulation. A follow-up is recommended when using injectable gonadotropins, because of the higher risk of multiple pregnancy and the risk of Ovarian Hyperstimulation Syndrome (OHSS).

When ovulation induction is prescribed without monitoring (usually with oral medication), frequent intercourse is recommended, and can be timed using home ovulation kits. When ultrasound monitoring is prescribed, its goal is to confirm the ovarian response and monitor the number and size of the growing follicles. When these are deemed mature (≥17-18 mm), ovulation is triggered with an injection of human Chorionic Gonadotropin (hCG). Ovulation trigger can be followed by a timed intercourse, or an intrauterine insemination, depending on the indication.