New IVF techniques increase fertilisation success rates

At the Fertility Show, a conference held in London, Dr Mónica Alarcón, a gynaecologist at the fertility clinic, Genefiv in Spain, discussed two new techniques that will give patients a greater chance of conceiving a child through IVF.

This article, written by Dr Alarcón is a summary of her presentation.

Increasing the success of IVF through improving the selection of sperm and eggs

Two new IVF technigues – IMSI and Oosight scanning – can improve the success rate of IVF by selecting the best sperm and eggs for use in creating an embryo for implantation:

  • IMSI (intracytoplasmic sperm injection morphologically selection) is a variation of ICSI (intracytoplasmic sperm injection), the technique of selecting and injecting sperm into the middle of the egg. IMSI uses a new incredibly high-powered microscope during the selection process to exclude unsuitable sperm
  • The Oosight technique enables close scrutiny of the egg during the selection process in order to exclude eggs that could potentially result in chromosomally abnormal embryos.

The two techniques both improve pregnancy rates and lower the chance of miscarriage.

Improved selection of sperm improves pregnancy rates

Dr Alarcón observed that the IMSI technique “allows us to examine sperm at a magnification of 6,000, something that was not previously possible. We can study the structure of the sperm in minute detail and discard those with deformities or that we think are not suitable for IVF.”

The IMSI technique considerably speeds up the process of selecting high-quality sperm as it makes it much easier to spot sperm that do not have the correct structure, which reduce the success rate of IVF. The correct structure is defined by the World Health Organisation as being symmetrical, smooth and oval, with a straight tail, a fixed core and a transparent colour.

The results of this technique showed, according to Dr. Alarcón "an increase in the rates of fertilisation and implantation, increased embryo quality and lower rates of abortion."

Improved egg selection increases IVF success rates

Dr. Alarcón explained that Oosight screening "enables close examination of the internal structure of the egg to ensure the best choice for fertilisation. It also enables more accurate injection of the sperm into the egg to avoid damaging the chromosomes, which would make an egg unusable.”

The Oosight technique is non-invasive and is particularly recommended for older women whose eggs have been frozen, a factor that increases the difficulty of creating an embryo. The technique takes into account the affects of freezing and unfreezing on the eggs while also measuring density of the eggs, factors that will affect the likelihood of eggs reaching the pre-embryonic stage prior to implantation.

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