Increasing the dose of hormones in suboptimal patients can help improve their response to IVF
The success of assisted reproduction treatments depends on multiple factors such as patient age, ovarian reserve, levels of anti-Müllerian hormone, antral follicle count, body mass index and response to previous cycles. All of these factors can help guide the choice of protocol in each case, and to predict the chances of success of a given treatment.
For this reason the Reproductive Medicine Unit of Dexeus Mujer, headed by Dr. Beatriz Alvaro Mercadal, conducted a retrospective study among 735 IVF patients at Dexeus Mujer to determine the clinical characteristics of women who are theoretically more or less likely to achieve pregnancy, and to observe the results after one or two IVF cycles, in order to establish whether predictions were confirmed and which circumstances may cause patients initially classified as suboptimal to respond as optimal patients, and vice versa. This information could be useful with a view to modifying certain guidelines in the treatment protocol to be followed in these cases.
To this end, a study sample of 735 women was selected who were classified into the following categories based on the number of oocytes harvested after IVF treatment: low responders (less than 4 oocytes per ovary), normal responders (between 4 and 15 oocytes) and hyper-responders (more than 15). Normal responders were subdivided into two further categories: optimal (between 10 and 15) and suboptimal (between 5 and 9). Patients who did not achieve pregnancy after the first cycle and underwent a second were checked for whether or not their treatment response was consistent with the initial classification, and what parameters had changed.
The results, which were recently published in Gynecological Endocrinology, showed that only 48% of patients showed a suboptimal response to the first cycle after egg retrieval. For fresh transfers, pregnancy rates were similar between the optimal and suboptimal categories (35.3% and 34.2%, respectively). However, the cumulative pregnancy rate was higher in women classified as "optimal" (51.5% vs. 37.4%). A higher number of oocytes probably increases the likelihood of having more high-quality embryos to choose from.
Analysis of the outcomes of the second cycle in patients who did not become pregnant after the first and repeated treatment found significant differences between the two groups, and that some of the patients who had been initially classified as optimal showed a suboptimal response, and vice versa: 18.9% of patients in the suboptimal category showed optimal response, and 36.9% of those in the optimal category showed a suboptimal response. The authors observed that in patients who received a higher dose of gonadotropins during their second cycle, response improved, showing that a slight increase in the dosage of hormones in the second ovarian stimulation treatment could help improve the outcome.
The likelihood of optimal response was calculated using a statistical model. In patients with a good prognosis, but in whom the number of harvested oocytes was lower than expected, the response to treatment may have been influenced by genetic polymorphisms involved in ovarian response. Nevertheless, the authors concluded that broadening the study by increasing the sample size could help individualise treatment protocols and optimise hormone dosing.
Characterization of a suboptimal IVF population and clinical outcome after two IVF cycles
Alvaro Mercadal B, Rodríguez I, Arroyo G, Martínez F, Barri PN, Coroleu B.
Gynecol Endocrinol.2017 Sep 3:1-4. doi: 10.1080/09513590.2017.1369515