In vitro maturation and its role in clinical assisted reproductive technology

In vitro maturation (IVM) refers to maturation in culture of immature oocytes that may or may not have been exposed to short courses of gonadotropins. Approximately 5000 live births have occurred as a result of IVM since the 1970s. Currently, IVM is reserved for carefully selected patients at risk for ovarian hyperstimulation syndrome and for those with contraindications to hormone administration. The technology is still considered experimental.

The objective of this study was to identify a role for IVM and discuss clinical practices based on the current literature.

We conducted a literature review of all available and published data. Relevant studies were identified using PubMed and MEDLINE. Search parameters included "in vitro maturation or IVM" and "oocyte maturation." Multiple case-control studies were identified comparing reproductive outcomes between conventional in vitro fertilization (IVF) and IVM, but no randomized controlled trials have been reported to date comparing IVF and IVM.

Results from retrospective and prospective observational studies have shown decreased live birth and implantation rates in comparison to conventional IVF/intracytoplasmic sperm injection for patients with various indications for IVM. However, rates of ovarian hyperstimulation syndrome were significantly reduced in studies with patients with polycystic ovary syndrome.

Although the pregnancy rate is lower than conventional IVF, IVM is a safer and simpler alternative to conventional IVF. Future research needs to focus on improving implantation and live birth rates before universal implementation.