Anogenital Distance and Endometriosis: Results of a Case-Control Study

AGD is the distance measured from the anus to the genital tubercle. Recent evidence suggests that a shorter AGD, a sensitive biomarker of the prenatal hormonal environment, could be associated with higher endometriosis risk. However, studies investigating AGD in affected women are scanty. We have set up a case-control study recruiting nulliparous women (aged 18-40 years) with endometriosis between 2017 and 2018. Cases were 90 women with a surgical or with a current nonsurgical diagnosis of endometriosis (n = 45 deep infiltrating endometriosis (DIE), and n = 45 ovarian endometrioma (OMA)). Controls were 45 asymptomatic women referring for periodical gynaecological care and without a previous diagnosis of endometriosis. They were matched to cases for age and BMI. For each woman, two measures were obtained using a digital calliper: AGD_AC, from the clitoral surface to the upper verge of the anus, and AGD_AF, from the posterior fourchette to the upper verge of the anus. Each distance was derived from the mean of six measurements acquired from two different gynaecologists. The mean ± SD AGD_AC in women with DIE, OMA and without a diagnosis of endometriosis was 76.0 ± 12.1, 76.1 ± 11.1 and 77.8 ± 11.4 mm, respectively (p = 0.55). The mean ± SD AGD_AF in women with DIE, OMA and without a diagnosis of endometriosis was 22.8 ± 5.0, 21.7 ± 9.0 and 23.7 ± 7.8 mm, respectively (p = 0.38). Our study failed to find an association between AGD and the presence of endometriosis. AGD does not seem to represent a reliable indicator of the presence of endometriosis to be used in clinical practice.