IVM (In-Vitro Maturation) is a variation of conventional IVF where the big difference is that immature eggs are also collected, and these are then ‘matured’ and fertilised alongside mature eggs. Doing this makes it possible for very little or no drug stimulation to be given before egg collection (which makes up a major part of the treatment costs and extends the length of the cycles in standard IVF protocols). As a relatively new protocol (since about 2008) clinics are still perfecting the retrieval and maturation of immature eggs and ensuring the womb lining is receptive for implantation.i
When to consider IVM
IVM may be the most suitable option when:
- The woman has a susceptibility to developing ovarian hyper-stimulation syndrome (OHSS)
- The ovaries are polycystic (PCO)
- A couple’s infertility is seen as being due only to male factors
The IVM protocol
Mature eggs are collected before ovulation (as with conventional IVF) but a number of smaller, immature eggs are collected alongside the mature egg that develops in the dominant follicle each menstrual cycle. A number of these immature eggs are then ‘matured’ in an incubator for 24-48 hours and normally 70-80% of them will successfully mature, which are then fertilised, incubated and transferred to the womb in exactly the same way as in conventional IVF.
A human chorionic gonadotropin (hCG) injection is given before egg collection to prevent the follicles rupturing prematurely and to aid the maturation and detachment of eggs from the follicle wall. In cases of a mix of IVF/M a course of mild FSH stimulation is given to increase the number of eggs that might be collected.
- It’s possible to carry out IVM during a woman’s natural menstrual cycle, which avoids