In this video, Silvia Azaña, an embryologist at inviTRA, explains what a low ovarian response means:
Low ovarian response is defined as a low number of mature eggs obtained after the process of ovarian stimulation in an IVF treatment. Nevertheless, specialists do not have a universal consensus for defining a poor response to ovarian stimulation.
According to the Bologna criteria, a low response is considered to be present when at least two of these criteria are clearly met:
- A maternal age over 40 or any other potential risk factor for low response.
- Previous cycle with low response. A cycle is considered to have had a low response if three or fewer oocytes are successfully obtained after following a standard ovarian stimulation protocol.
- Ovarian reserve test that shows a decreased result: antral follicle count that is lower than 5-7, or antimüllerian hormone below 0.5-1.1 ng/mL.Furthermore, it is also considered that a woman is a low responder when, after undergoing two cycles of ovarian stimulation at maximum doses, two low responses are obtained.
Nevertheless, the later POSEIDON Classification managed to achieve a superior stratification of the female patients, depending on the age (under or over 35 years old) and ovarian reserve (an antral follicle count greater or less than 5 and AMH greater or less than 1.2 ng/mL).
The frequency of a low response to ovarian stimulation during fertility treatments shows variability, but it is estimated that it appears in 9 to 24% of patients. Therefore, it is essential that the fertility treatment, along with the ovarian stimulation protocol, is customized right from the start.
