A patient can be classified as having poor response when the number of oocytes obtained during a cycle of in vitro fertilisation is under what was expected. The criteria generally used to label a patient as a poor responder is when 3 or fewer oocytes are retrieved and she has incredibly low ovarian reserve markers (fundamentally, AMH and AFC).
The fact that these women’s response to stimulation protocols is deficient means that their chances of success are jeopardised and they sometimes contemplate giving up treatment and ending their childbearing age without having had children.
This is why a global assessment of each case by a multi-disciplinary team is so important. Gynaecologists, geneticists, embryologists and specialists in molecular biology with experience both in healthcare and as researchers need to design a personalised strategy that will optimise the chances of giving birth to a healthy child.
The strategy ranges from diagnostic tests that can rule out causes of the patient’s poor response that may put the patient’s health at risk, to genetic tests that reduce the risks for the future child or even help the team to come to a decision regarding the best strategy for treatment.
The specific genetic analysis for patients with poor ovarian response includes a karyotype and a genetic test for fragile X syndrome. Should any of these tests come back positive, this enables the team to understand the origin of the patient’s fertility issue and avoid the birth of a child with a serious genetic disorder.
At Instituto Bernabeu, following over 4 years of research, we have identified the genes that play a role in ovarian response. This has enabled us to develop an innovative genetic study of ovarian function (IBGENFIV). This genetics test enables the team of doctors to design pharmacological treatment that is personalised to the patient’s needsº in order to determine the most appropriate medication for her genetic profile. This improves the chances of pregnancy because an increased number of oocytes are obtained.
Vitrification is a technique that practically eliminates the formation of ice crystals, the main issue during cryopreservation processes. Its routine use in laboratories has contributed towards improving results enormously in comparison with other more traditional techniques. This is particularly true in the case of oocytes and we have been able to obtain very high survival rates. Progress of this kind has given many patients a clear advantage, including those with a poor response to ovarian stimulation. In these cases, an alternative option involves cryopreserving the oocytes obtained over successive courses of stimulation in order to store them until the necessary number is obtained (similar to what we might expect from a patient with normal response) and then fertilise them all at the same time. In doing so, the number of available embryos and the chances of getting pregnant increase.
In our opinion, the strategy for obtaining oocytes in poor responder patients needs to be different to conventional stimulation protocols. Dealing with each case individually is key. Preparation during the previous cycle using adjuvant drugs can sometimes improve response during stimulation. In other cases, mild protocols can optimise response.
It should be kept in mind that as oocyte vitrification progresses, the patients cared for at Instituto Bernabeu can generate oocytes from different stimulation cycles. This makes treatment more accessible and facilitates collection of the largest possible number of ova in the shortest possible period of time.