When a sperm meets an egg, a chain of molecular events commences. One of these events is the release of calcium from calcium stores within the egg. This calcium release results in oocyte activation, which allows fertilisation to occur.

Sometimes, eggs fail to release calcium. This can be due to problems within the egg or deficiencies within the sperm. In assisted reproductive treatment, this can result in a low number of eggs fertilising or, in a small number of cases, no eggs may fertilise at all.

Low fertilisation rates with IVF are typically attributed to sperm abnormalities (poor motility or the inability of the sperm to penetrate the egg’s shell/zona pellucida, for example). When low fertilisation rates persist with ICSI insemination, it is thought that oocyte activation problems are responsible. Please click here for more information about the difference between IVF and ICSI.

At Oasis Fertility Centre, we offer calcium ionophore for assisted oocyte activation. Following ICSI insemination the eggs are washed in a solution containing calcium to mimic the normal release of calcium necessary for oocyte activation. This is thought to improve fertilisation rates.