Testicular position related to fetal weight: analysis in 144 human fetuses

Abstract

Purpose The objective of this paper is to present an analysis concerning testicular migration and its position correlated to body weight during the fetal period in humans. Material and methods We studied bilaterally 288 testes taken from 144 human fetuses that died of causes unrelated to the urogenital tract. The fetuses were well preserved and none had any kind of detectable congenital malformations. Gestational age ranged between 10 and 35 weeks after conception and was estimated according to foot length criteria. The fetuses were also evaluated in regard to body weight in gm. The abdomen, inguinal region and scrotum were opened and the position of the testes was recorded according to body weight. The testis was regarded as abdominal when it was proximal to internal ring, canalicular when it was found between the internal and external inguinal ring and descended or scrotal when it was inferior to the external ring. Results In fetuses under 500gm. (76 fetuses - 152 testes) 147 testes were in the abdomen and only 5 testes (6.5%) were in the canal. In fetuses with body weight between 501 and 1000gm. (43 fetuses – 86 testes), 54 testes (68.6%) were abdominal , 28 testes (32.5%) were in the canal and only 4 testes (4.6%) were scrotal. In fetuses with body weight between 1001 and 1500gm. (15 fetuses – 30 testes), 4 testes (13.3%) were abdominal, 3 testes (10%) canalicular and 23 testes (76.6%) scrotal. All testes were in the scrotum in fetuses weighing more than 1500 gm. (10 fetuses – 20 testes). The testes had not descended into the scrotum in any fetus weighing 740gm. or less. Conclusions We conclude that all testes had descended to the scrotum in fetuses weighing more than 1500gm. All the testis was still in an abdominal or in a canalicular position in fetuses until 740gm.