Carrying out a control of endometrial thickness by ultrasound is not indispensable, except in cases where it has been medically recommended. Most women have a completely normal endometrial development even though they may require the help of assisted reproduction and with the usual treatment guidelines.
In certain cases in which we suspect a hypotrophic endometrium, that is, an under-developed endometrium (eg. long-duration menopause without hormone replacement therapy, history of radiation exposure, repeated surgery on the uterus etc.), we will recommend carrying out a control of the endometrial thickness.
In cases of thin endometriums, we slightly increase the dosage of estrogen because we know that high doses are not effective and can also increase the risk of thrombosis. The growth of the endometrium in these borderline cases once the standard dose of drugs has been exceeded is not dependent on the dose and duration of treatment with estrogen, which means we cannot change the development potential of the endometrium.
Our own experience, together with the publications on oocyte reception, which include a large number of cases, shows us that there is no direct relationship between endometrial thickness and pregnancy rate. In these publications they talk about pregnancy rates that are similar in both endometriums with normal thicknesses as in endometriums with thicknesses below 5mm (Soares et al, JCEM 2005 – Age and Uterine receptiveness. Predicting the outcome of oocyte donation cycles, Remohi et al. Hum Reprod, 1997 Endometrial thickness and serum oestradiol Concentrations as predictors of outcome in oocytedonation.).
Some patients, of their own volition, do an ultrasound for their own peace of mind but, as we have already stated earlier, there is no scientific evidence for doing it systematically. If they would like to do it, we recommend carrying it out after 12 to 14 days of estrogen treatment.