Are the ESHRE/ESGE criteria of female genital anomalies for diagnosis of septate uterus appropriate?

Sir, We are following with interest the European Society of Human Reproduction and Embryology/European Society for Gynaecological Endoscopy (ESHRE/ESGE) initiative to create a new classification of female genital tract congenital anomalies (Grimbizis et al. 2013). We applied the European criteria routinely using three-dimensional (3D) ultrasonography, while simultaneously classifying our patients based on the American Society for Reproductive Medicine (ASRM) criteria (Buttram et al. 1988), complemented by additional common morphometric criteria used to differentiate septate, bicornuate and arcuate uteri (Bermejo et al. 2010, Ludwin et al. 2013). We encountered three problems: (i) practical adaptation of the ESHRE–ESGE classification criteria for septate uterus diagnosis, (ii) an increased frequency of septate uterus diagnoses and all uterine congenital anomalies according to the ESHRE–ESGE compared with the ASRM classification (because a septate uterus was diagnosed in cases where uteri fulfilled previous morphometric criteria for arcuate and in some cases normal uteri) and (iii) potentially important clinical implications of the new classification. We believe that application of ESHRE–ESGE criteria may cause difficulties because (i) the thickness of the uterine wall as the reference value for the septate uterus diagnosis may vary in different regions of the uterus. Thus, it is important to determine where and how it should be measured and (ii) the original definition of septate uterus is an abnormally shaped uterine cavity. The ratio of myometrial thickness to the size of the internal fundal indentation may not reflect the actual anatomical relationships in the uterus and lead to false diagnoses (Fig. 1). Another drawback of the relative criteria is that they are not compatible with endoscopic techniques since myometrial thickness cannot be assessed. ESHRE/ESGE criteria for diagnosis of septate uterus; in a uterus with a thin myometrium and concave (a) or flat (b) external contour of the fundus, even a small internal fundal indentation is diagnosed as a uterine septum; in uteri with excessively thick walls or large external convexity (c) of uterine fundus, even substantial partitioning might not be diagnosed as septum. (ESHRE, European Society of Human Reproduction and Embryology; ESGE, European Society for Gynaecological Endoscopy.) The application of the ESHRE/ESGE criteria may have serious clinical implications. The diagnosis of uterine septum on the basis of relative ESHRE/ESGE criteria is not supported by retrospective results and prospective studies of corrective surgery. This applies to eligibility for hysteroscopic metroplasty of patients with recurrent miscarriages who have a small internal fundal indentation; the proposed treatment may not improve obstetric results. A more serious concern is that prophylactic metroplasty may be performed in these cases prior to assist reproductive technology procedures. Additionally, the new classification may affect the assessment of anatomical results of corrective surgery, which could result in frequent repeat procedures, possibly without any significant effect on reproductive performance. This might affect the decision to re-operate in cases where previous retrospective studies suggested no indication for complementary metroplasty (residual septum <1 cm) and may lead to a thin absolute myometrium that could cause future pregnancy complications. It is worth considering whether the new classification should implement the length of the internal fundal indentation in relation to the length of the non-partitioned region of the uterus as a relative criterion for the diagnosis of uterine septum. We believe that diagnosis of uterine septum according to the ESHRE/ESGE criteria in females with low absolute internal fundal indentation (≤1.5 cm) should be considered carefully as an indication for surgery, and would be more applicable to clinical trials than routine practice. It appears that the structure of the new classification is flexible enough to allow for changes in diagnostic criteria based on the results of future studies. None declared.