Chin Helen B, Amabile Thomas H, Kelly Andrea, Patchel Stacy A, Darge Kassa, Kaplan Summer L, Ford Eileen G, Stallings Virginia A, Rogan Walter J, Umbach David M
Department of Global and Community Health, George Mason University, Fairfax, Virginia, USA.
Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
Andrology. 2025 Feb;13(2):202-207. doi: 10.1111/andr.13669. Epub 2024 May 31.
Testis volume, an indicator of the reproductive development during minipuberty, is commonly measured by Prader orchidometer, despite ultrasound being the gold standard. Data are lacking on the longitudinal relationship between these two measures and on the stability of boys' relative testis size across infancy.
To examine the relationship between ultrasound-based and orchidometer-based testis volume measurements and to assess the stability of relative testis size among individual boys in the study.
The Infant Feeding and Early Development study is a longitudinal cohort of healthy infants recruited from hospitals in the Philadelphia area during 2010-2013. We measured testis size from birth to 28 weeks in 147 infants using Prader orchidometry (nine study visits) and ultrasound (five study visits). We modeled testis growth, extracted predicted volumes for each boy on each day of the study, and ranked these volumes from smallest to largest.
The average testis volume trajectory exhibited linear growth over the first 16 weeks followed by slower growth and then a plateau. Prader orchidometry overestimated testis size by almost 3-fold, compared to ultrasound. A range of ultrasound volumes corresponded to each bead size (e.g., bead size of 1 cm corresponded to an ultrasound-based volume between 0.11 and 0.87 cm). Infants changed rankings of median of 22 positions (of 147) across the entire 6-month follow-up. Infants' ranks near birth were highly correlated with their ranks at the end of the study.
Consistent with other studies, we found wide variability in testis size during infancy and that Prader orchidometry overestimates testis size. When compared to ultrasound, orchidometry only crudely estimates testis size in this age group. Ultrasound-based volumes generally showed stability in relative testis size across infancy.
Accurate measurement of testis size is difficult using orchidometry in infants. This highlights the need for ultrasound for accurate measurement, with a one-time measurement likely sufficient to determine relative testis size across the first 6 months of infancy.
睾丸体积是小青春期生殖发育的一个指标,尽管超声检查是金标准,但通常使用普拉德睾丸计进行测量。关于这两种测量方法之间的纵向关系以及男孩在婴儿期相对睾丸大小的稳定性的数据尚缺乏。
研究基于超声和基于睾丸计的睾丸体积测量之间的关系,并评估研究中个体男孩相对睾丸大小的稳定性。
婴儿喂养与早期发育研究是一项纵向队列研究,于2010年至2013年期间从费城地区的医院招募健康婴儿。我们使用普拉德睾丸计(9次研究访视)和超声(5次研究访视)对147名婴儿从出生到28周的睾丸大小进行了测量。我们对睾丸生长进行建模,提取每个男孩在研究期间每天的预测体积,并将这些体积从小到大进行排名。
在最初的16周内,平均睾丸体积轨迹呈线性增长,随后增长缓慢,然后趋于平稳。与超声相比,普拉德睾丸计高估了睾丸大小近3倍。每个珠子大小对应一系列超声体积(例如,珠子大小为1厘米对应基于超声的体积在0.11至0.87立方厘米之间)。在整个6个月的随访中,婴儿中位数排名变化了22个位置(共147个位置)。婴儿出生时的排名与研究结束时的排名高度相关。
与其他研究一致,我们发现婴儿期睾丸大小存在很大差异,并且普拉德睾丸计高估了睾丸大小。与超声相比,睾丸计在这个年龄组中只能粗略估计睾丸大小。基于超声的体积在婴儿期相对睾丸大小方面通常显示出稳定性。
在婴儿中使用睾丸计难以准确测量睾丸大小。这凸显了使用超声进行准确测量的必要性,一次测量可能足以确定婴儿期前6个月的相对睾丸大小。