Genetic profile of SNP(s) and ovulation induction.

Obtaining an adequate number of good quality oocytes while minimizing adverse drug reactions (ADRs) and cycle cancellation rates is considered the gold standard in controlled ovarian hyperstimulation (COH) for fertility treatment. Patients who undergo IVF/ICSI cycles tend to present with different responses to exogenous gonadotrophin administration. Research has shown that the secret probably lies in the various single nucleotide polymorhisms (SNPs) in their receptor genes. The decryption of human genome provided specialists with additional information in assessing and even predicting ovarian response to COH. In this context, the study of Pharmacogenomics, Pharmacogenetics and SNPs unravels as a promising field in optimizing fertility treatment. Several SNPs in FSH and estrogen receptor genes have been detected so far, but only three of them, one in FSH receptor and two in estrogen receptor genes have been associated with ovarian response to COH. It seems that the Asn/Ser variant of the FSH receptor functions more efficiently, while the Ser/Ser and Asn/Asn variants have a tendency to resist to FSH stimulation. With regards to estrogen receptor 1 (ESR1), the Pvull and the Xbal polymorphisms seem to be associated with differences in the response to ovarian stimulation, while the Rsal polymorphism in estrogen receptor 2 (ESR2) is currently under investigation. There exists evidence supporting the hypothesis that a set of genes, all related to the FSH hormone mechanism of action, may participate along with other factors to the control of ovarian response to FSH, thus a cautious interpretation of polymorphism detection results is considered mandatory. However, identifying potential genetic markers that could predict ovarian response and implementing them in routine screening tests for every woman entering an IVF/ICSI cycle, would be able to tailor fertility treatment to each patients needs thus maximizing the success rate and eliminating potential side-effects of fertility drugs.