What is IVM?
With in vitro maturation (IVM) eggs are removed from the ovaries and are collected when they are still immature. They are then matured in the laboratory before being fertilised.
The difference between IVM and conventional in vitro fertilisation (IVF) is that the eggs are immature when they are collected. This means that the woman does not need to take as many drugs before the eggs can be collected as she might if using conventional IVF, when mature eggs are collected.
In vitro maturation candidates
The best candidates for IVM (in vitro maturation) are young women with large numbers of egg containing follicles or women who have attempted stimulated in-vitro fertilization and had production of a large number of eggs.
Ideally, women under the age of 30 or 35 would be expected to have the greatest likelihood for having many eggs.
There are two tests that are used to identify women with a large number of eggs. Using vaginal ultrasound, the ovaries can be seen and the egg containing follicles can be counted for each ovary. An excellent number of follicles to be a great IVM candidate would be more than 15 follicles in each ovary. A blood test can also tell about the number of eggs in the ovaries. A hormone called AMH (anti-mullerian hormone) is produced by follicles in the ovary. A higher AMH level indicates a larger number of eggs in the ovaries. AMH levels will vary by age. As women get older and the number of eggs in their ovaries decrease, the AMH levels will start to decrease. For IVM, a woman should have an AMH level in the upper half for her age group.
Women who are obese are not good candidates for IVM. The ovaries are very small when they are not first stimulated by fertility medications. This makes them more difficult to see on ultrasound. Obesity also makes it more difficult to see the ovaries on ultrasound and therefore makes it more difficult and more risky to try to remove the eggs from the ovaries.
Women who have taken injectable fertility drugs previously and who had a very vigorous response or had a treatment that was cancelled for fear of hyperstimulation syndrome, may be very good candidates for IVM.
In vitro maturation techniques
The technique involved for in vitro maturation begins with a woman having a transvaginal ultrasound performed between day 3 and 5 of her menstrual cycle. If she does not have evidence for regular menstrual cycles and natural ovulation, she would be a candidate for in vitro maturation alone. If she has regular ovulatory cycles, then she is a candidate for natural cycle in vitro fertilization combined with in vitro maturation.
An injection of hCG is given and the eggs are retrieved 36 hours later. The immature eggs are placed in a petri dish containing specialized media to help the eggs mature. Once the eggs are matured, they are injected with sperm - this is a fertilization technique known as ICSI . The injected aggs are now cultured for several additional days to allow the embryos to develop. This is the same technique that is used in standard in vitro fertilization.
During this time, the female is given hormones to prepare the uterine lining. Both estrogen and progesterone are given after the ggs have been retrieved. A few embryos are then selected and an embryo transfer is performed.