In vitro maturation (IVM) is an assisted reproductive technology in which partially immature eggs are retrieved from antral follicles and matured in the laboratory, rather than inside the ovaries through hormonal stimulation.
Unlike conventional IVF, where hormonal stimulation is used to mature the eggs before retrieval, IVM involves collecting eggs while they are still immature. These eggs are then cultured in specialized laboratory media, allowing about 50% of them to reach full maturity. Once mature, they can be fertilized with sperm to create embryos.
Before undergoing IVM, a woman should have at least 10 to 15 antral follicles visible on ultrasound to ensure a sufficient number of eggs for maturation.
Initially, in vitro maturation (IVM) was offered only to women who could not undergo ovarian stimulation due to a history of:
- Severe ovarian hyperstimulation syndrome (OHSS)
- Hormone-sensitive cancers
Today, IVM is also considered for:
- Women at high risk of OHSS, including those with polycystic ovary syndrome (PCOS)
- Fertility preservation, particularly for women who cannot delay cancer treatment for ovarian stimulation
However, IVM is not suitable for women who produce only immature eggs after ovarian stimulation, as persistent egg immaturity often indicates poor egg quality, which IVM cannot fix.
This technique can be especially effective for women with FSH resistance, who often have no menstrual cycles and fail to develop pre-ovulatory follicles, even after ovarian stimulation. For these women, eggs can be retrieved without stimulation, matured in the lab, and fertilized to create embryos.
Can IVM Be Used for Premature Menopause?
In most cases of premature ovarian insufficiency (POI) (early menopause), IVM is not effective because too few antral follicles are present. However, there are two exceptions:
- Women with FSH resistance, who have a similar profile to POI patients but may still have recruitable follicles.
- Women with early-stage autoimmune POI, where some antral follicles remain visible despite the absence of menstrual cycles.
In these rare cases, IVM may be an option.
