Intracytoplasmic sperm injection (ICSI)
Intracytoplasmic sperm injection (ICSI) has been thought to be necessary for the fertilization of in vitro matured oocytes even in conditions where sperm parameters are not impaired. Another reason for using ICSI instead of insemination after IVM is that the assessment of oocyte maturity is more difficult with intact cumulus cells. However, insemination may be a good alternative after IVM when the sperm is suitable for IVF. It can be speculated that the intact cumulus cells somehow enhance cytoplasmic maturation and developmental competence of the oocytes.
Embryo transfer and Endometrial preparation
One of the challenges of IVM is to prepare the uterus for implantation in only a few days between the oocyte retrieval and embryo transfer. Because immature oocytes are usually retrieved before the dominant follicle develops, the endometrium is exposed to relatively low levels of estradiol by the time of oocyte pick-up. As a result, there is dyssynchrony between the phase of the endometrium and the cleavage stage embryo. Therefore, adequate preparation of the endometrium is of crucial importance in an IVM cycle because of the absent LH surge at the time of oocyte collection. The most commonly used protocol for endometrial preparation consists of estradiol valerate 2-4 mg daily from the day of immature oocyte collection and progesterone intravaginal started 48 hours later at the time of microinjection or insemination. In case of pregnancy, it is important to continue the hormone supplementation long enough as there is no endogenous pituitary or corpus luteum support.
Clinical outcome and follow-up of children
The clinical outcomes of IVM have continued to improve after the modest results of the early studies. The average pregnancy rates in women with PCOS have been reported between 22 and 30%, and in women with normal ovaries between 18 and 30%, Recently a pregnancy rate per embryo transfer as high as 52% and implantation rate of 27% was reported after IVM and blastocyst transfers in highly selected cases.
The technological step that will eventually make offspring genetic engineering easier to do. Though that’s not why the technology was developed. In Vitro Maturation (IVM), which involves extracting eggs from an ovary at an earlier stage than In Vitro Fertilization (IVF). In IVM, eggs are collected from the ovaries while they are still immature. They are then matured in a laboratory for up to 48 hours before being injected with a single sperm – a process called intracytoplasmic sperm injection (ICSI)
IVM is important because it lower costs, reduces pain, reduces time, and lowers risk. Plus, it might work in cases where standard IVF fails. The advances in IVM development fit into a larger trend of improvements in so-called assisted reproduction technologies (ART). The techniques for cost and risk reductions are going to be ready and available when declining costs of gene testing technologies make artificial means of starting pregnancies far more desirable.
In standard IVF, the woman takes fertility drugs for five weeks to stimulate production of her eggs, which are then collected direct from her ovaries under the guidance of ultrasound, before being fertilised in the laboratory. The procedure is time consuming and uncomfortable and for the third of women with polycystic ovaries there is a one in 10 risk of severe ovarian hyperstimulation syndrome, a dangerous side-effect that in rare cases can prove fatal.
Since IVM will reduce risks and costs more women will opt for medical assistance to start pregnancies. The lowered risks will also play a big role in enabling much more widespread use of in vitro techniques once genetic testing advances to the point that women and couples gain the ability to select desired genetic traits. We need cheap DNA testing first to use to discover what all the genetic variations mean. Then with that knowledge prospective parents will use genetic testing to select embryos for implantation. Then selective pressures on human evolution will skyrocket. I figure given the continued rapid decline in the cost of DNA testing technologies we are somewhere between 5 and 15 years away from that turning point.