Instituto Bernabeu discovers fertility genetic variants

Following years of research, the Poor Responder Unit at Instituto Bernabeu has, for the first time, discovered the genes that play a role in ovarian reserve. This makes choosing the most appropriate medication for the patient’s genetic make-up possible, thus optimising ovarian response.

Women are nowadays having children later on in life. This is a fact and an increasing trend. The chances of falling pregnant decrease dramatically from 35 years of age and become very low when over 40 years of age.

When pregnancy does not come naturally and we have to turn to in vitro fertilisation treatment, the aforementioned biological limitation implies two things: getting an understanding of ovarian reserve is key and personalising ovarian stimulation is essential in order to retrieve the greatest possible number of eggs. These will later be fertilised and become embryos that are ready for transfer to the mother’s uterus.

Women generate eggs when they are still within their mother’s uterus. Once they are born, their ovaries will then never again generate new oocytes and it is for this reason that our research centres around optimising the existing ones.

The Poor Responder Unit at Instituto Bernabeu is aware that not all women responded equally to ovarian stimulation and we believe that this may be due to the fact that they have different genetic receptors for the hormones that stimulate ovulation.

Indeed, following a number of years of research, we have discovered that women have different hormone receptors and, depending on the type they have, their ovaries react in different ways. Such progress means that, for the first time, we are able to apply pharmacogenetics to assisted reproduction treatment, making a connection between the type of medication, the dose and the ovaries’ response. This means we are able to choose the most adequate type of medication for the patient’s genetic make-up, thus optimising ovarian response.

Personalising ovarian stimulation based on the type of receptor has enabled us to increase the number of eggs which can be retrieved. This increases the chances of pregnancy using the mother’s eggs and reduces the number of women who need to turn to egg donation because their ovaries do not respond to conventional protocols.

In an increasingly larger group of women who, as a result of having delayed motherhood until late in life, or because of other medical reasons, a greater or smaller number of eggs can mean the difference between having or not having a child.