잠복고환 발생의 빈도, 위험 인자 및 자연하강률

Abstract

Purpose: We studied the incidence, risk factors and spontaneous descent of cryptorchidism. Materials and Methods: A total of 813 consecutive male neonates delivered at Keimyung University Dongsan Medical Center during the period from June 2001 to June 2002 were examined at birth for cryptorchidism. Eighty boys with cryptorchidism and 733 normal boys were enrolled in this study. Fifty-six boys with cryptorchidism (87 testes) were followed at 1, 2, 3 and 6 months of age for evaluation of spontaneous testicular descent. Risk factors included birth weight, gestational weeks, other congenital anomalies, Apgar score, birth order, twin birth, mode of delivery, family history of cryptorchidism, maternal age, parity history, previous abortion history and maternal disease history. Logistic regression analysis was used to estimate the odds ratios. Results: The incidence of cryptorchidism was 4.4% in full term (28 out of 635) and 28.6% in preterm (52 out of 178) newborns. The overall incidence was 9.8%. All of the nonpalpable testes and 87.8% of bilateral undescended testes were found in premature babies. Low birth weight (＜2,500g) and preterm deliveries (＜37wks) were significant risk factors for cryptorchidism. All of 25 undescended testes in term boys and 50 undescended testes of premature boys had descended by age 6 months. Conclusions: The incidence of cryptorchidism in this study was higher than that of other studies. The premature newborns had a higher incidence of bilateral and nonpalpable cryptorchidism. Low birth weight and preterm deliveries were significant risk factors for cryptorchidism. There was an 86% chance of spontaneous descent by 6 months of age. (Korean J Urol 2003;44:1203-1207)