Ovarian stimulation is the use of injectable or oral fertility medicines during IVF to encourage the ovaries to develop multiple mature follicles, each potentially containing an egg, rather than the single egg released in a natural cycle. This increases the number of eggs available for retrieval and fertilisation. The response to stimulation is tracked with ultrasound scans and blood hormone tests throughout the cycle, and the treatment plan is adjusted by the treating specialist based on how the ovaries respond. Stimulation carries a risk of ovarian hyperstimulation syndrome (OHSS), particularly in women with a high egg reserve such as those with PCOS, so monitoring and individualised planning are used to reduce this risk. This entry does not describe specific doses or medicine choices, which are decided by the treating clinician.
Also known as: controlled ovarian stimulation, COS
Related India guides
Sources
- ICMR Standard Treatment Workflows (icmr.gov.in/standard-treatment-workflows-stws)
- Federation of Obstetric and Gynaecological Societies of India (fogsi.org)
Last reviewed: 9 September 2026. Written by the Antega Editorial Team. General information only — always follow the advice of your own clinic, doctor or pharmacist.