Frequently Asked Questions

Who can benefit from a pharmacogenetic test?
This test may be useful in selecting the optimal drug dosage for any woman being treated with drugs for fertility problems. The test may also predict who is more likely to succeed following minimal stimulation IVF or even natural cycle IVF (in which no drugs are used).

What is pharmacogenetics?
Pharmacogenetics is the study of how a person's genes can influence their response to medication. Even a single letter change out of the 6 billion letters of the entire DNA code can explain why different people respond to the same medicine in different ways. In some cases, such changes can mean harmful side effects or no effect at all of the medicine prescribed.

Why is pharmacogenetics important in assisted reproduction?
From the perspective of ovarian stimulation, the two worst outcomes are (i) a poor ovarian response and (ii) ovarian hyperstimulation syndrome (OHSS), both of which can lead to cancelled cycles. Doctors currently consider your age, body mass index, ovarian ultrasound results, hormonal profile (including follicle stimulating hormone -FSH) and previous response to FSH to select an optimal drug dose that will limit the chances of OHSS and poor response. A growing body of evidence is supporting the production of a patient specific genetic profile that helps identify women most likely to over-respond or poorly respond to the drugs used in IVF. In this way, a simple blood test can help to customise your treatment. We believe that this test will help to improve the safety and efficacy of IVF treatment by allowing us to prescribe the right drug, at the right dose for every patient.

How common are the genetic changes and are they associated with disease?
The tiny genetic changes are present in all people and are not usually associated with disease. Many have no known effects at all. The changes we are testing for only affect the way women respond to certain medications. The specific genetic profile associated with poor response to FSH may be present in almost 1 in 4 women, but this proportion varies according to their ethnic origins.

What does the screening test involve?
The screening test is performed on the woman providing eggs only. Using our current test, we can identify up to five different genetic regions which could influence a woman's ability to respond to the drugs (or the body's own naturally circulating hormones) involved in producing and maturing eggs. The test is performed after taking 5-10 mls of your blood. The test can be done at any time, is not affected by infertility treatment or menstrual cycle and, unlike the blood serum FSH test, the results do not change from month to month. The test will be performed prior to determining your stimulation drug dose requirements.

How are the results used?
The results are usually ready within two weeks of us receiving the blood sample and will be used to help determine your stimulation dose. Patients with a genetic profile associated with poor response to FSH may benefit from a higher initial dose than would otherwise have been selected based on age, BMI, basal FSH and so on.