Increased incidence of hypospadias in small-for-gestational age infants in a neonatal intensive-care unit

Objective To identify the incidence of hypospadias in children born prematurely and small-for-gestational age (SGA), and to compare this subgroup with infants of similar age and weight without hypospadias. Patients and methods Records from the neonatal intensive-care unit (NICU) of a major metropolitan hospital active in labour and delivery were reviewed over a 3-year period, specifically examining newborns admitted with the diagnosis of SGA, defined as a birth weight of < 10th percentile for gestational age. In all, 154 patients were identified and their charts reviewed, recording the presence and severity of hypospadias. gestational age, birth weight, placental weight, cord length, cord vessels, maternal age, parity, multiple births, drug exposure and associated comorbidity. A control group of age- and weight-matched infants without hypospadias were also identified and compared. Results Of the 154 patients, 17 (11%,) had hypospadias: the hypospadias was distal in nine, mid-shaft in four and proximal in four. The severity of hypospadias did correlate with the degree of prematurity or weight for gestational age. Placental weight, fetal weight, fetal to placental weight ratio and cord length were all lower in the hypospadias group than in the control group, but the differences were not statistically significant. The maternal age was evenly distributed (median 32 years, range 20-43). Most mothers were multiparous and births were multiple in five of 17 (30%). Cryptorchidism (three) and inguinal hernia (three) were present in four of the infants. Conclusions The incidence of hypospadias in SGA infants admitted to the NICU is >10 times higher than that reported for the general population. There was a trend to lower placental and fetal weight in SGA infants with hypospadias than in the controls. This finding merits further evaluation using a larger population database and suggests that factors resulting in SGA infants occur at a critical point early in development, affecting both somatic and urethral development.