Division of Male Reproductive Medicine and Surgery, Scott Department of Urology, Baylor College of Medicine, Houston, Texas, United States of America.
PLoS One. 2011 May 11;6(5):e18973. doi: 10.1371/journal.pone.0018973.
Anogenital distance (AGD), a sexually dimorphic measure of genital development, is a marker for endocrine disruption in animal studies and may be shorter in infant males with genital anomalies. Given the correlation between anogenital distance and genital development, we sought to determine if anogenital distance varied in fertile compared to infertile adult men.
A cross sectional study of consecutive men being evaluated for infertility and men with proven fertility was recruited from an andrology clinic. Anogenital distance (the distance from the posterior aspect of the scrotum to the anal verge) and penile length (PL) were measured using digital calipers. ANOVA and linear regression were used to determine correlations between AGD, fatherhood status, and semen analysis parameters (sperm density, motility, and total motile sperm count).
A total of 117 infertile men (mean age: 35.3±17.4) and 56 fertile men (mean age: 44.8±9.7) were recruited. The infertile men possessed significantly shorter mean AGD and PL compared to the fertile controls (AGD: 31.8 vs 44.6 mm, PL: 107.1 vs 119.5 mm, p<0.01). The difference in AGD persisted even after accounting for ethnic and anthropomorphic differences. In addition to fatherhood, on both unadjusted and adjusted linear regression, AGD was significantly correlated with sperm density and total motile sperm count. After adjusting for demographic and reproductive variables, for each 1 cm increase in a man's AGD, the sperm density increases by 4.3 million sperm per mL (95% CI 0.53, 8.09, p = 0.03) and the total motile sperm count increases by 6.0 million sperm (95% CI 1.34, 10.58, p = 0.01). On adjusted analyses, no correlation was seen between penile length and semen parameters.
A longer anogenital distance is associated with fatherhood and may predict normal male reproductive potential. Thus, AGD may provide a novel metric to assess reproductive potential in men.
肛殖距（AGD）是一种衡量生殖器官发育的性别二态性指标，在动物研究中是内分泌干扰的标志物，并且可能在具有生殖器官异常的男婴中更短。鉴于肛殖距与生殖器官发育之间的相关性，我们试图确定在有生育能力的男性与无生育能力的男性之间，肛殖距是否存在差异。
这项横断面研究招募了来自男科诊所的正在接受不育症评估的连续男性和有生育能力的男性。使用数字卡尺测量肛殖距（从阴囊的后侧面到肛门边缘的距离）和阴茎长度（PL）。使用方差分析和线性回归来确定 AGD、父亲身份和精液分析参数（精子密度、活力和总活动精子数）之间的相关性。
共招募了 117 名不育男性（平均年龄：35.3±17.4）和 56 名有生育能力的男性（平均年龄：44.8±9.7）。与有生育能力的对照组相比，不育男性的平均 AGD 和 PL 明显更短（AGD：31.8 与 44.6mm，PL：107.1 与 119.5mm，p<0.01）。即使考虑到种族和人体测量学差异，AGD 的差异仍然存在。除了父亲身份外，在未调整和调整后的线性回归中，AGD 与精子密度和总活动精子数均呈显著相关性。在校正人口统计学和生殖变量后，男性的 AGD 每增加 1cm，精子密度增加 430 万个/mL（95%CI 0.53,8.09，p=0.03），总活动精子数增加 600 万个精子（95%CI 1.34,10.58，p=0.01）。在调整后的分析中，阴茎长度与精液参数之间没有相关性。
较长的肛殖距与父亲身份相关，并且可能预测男性正常的生殖潜能。因此，AGD 可能提供一种评估男性生殖潜能的新指标。
