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19–22 APRIL, 2017, BARCELONA, SPAIN
09:09–09:12
S14-6 (PP)
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IMPACT OF MATERNAL AND PLACENTAL FACTORS,
BIRTH WEIGHT, ACCOMPANIED MALFORMATIONS
ON THE CLINICAL CHARACTERISTICS OF HYPOSPADIAS
IN IDENTICAL OR FRATERNAL TWINS
Ji Yong HA
1
, Sang Hoon SONG
2
, Jae Shin PARK
3
, Won Yeol CHO
4
, Kyung Do KIM
5
,
Sungchan PARK
6
and Kun Suk KIM
7
1) Keimyung University, School of Medicine, Department of Urology, Daegu, REPUBLIC OF KOREA - 2) Asan Medical
Center, University of Ulsan College of Medicine, Department of Urology, Seoul, REPUBLIC OF KOREA - 3) Daegu
Catholic University Medical Center, Departments of Urology, Daegu, REPUBLIC OF KOREA - 4) Dong-A University
Hospital, Department of Urology, Busan, REPUBLIC OF KOREA - 5) Chung-Ang University Hospital, Department
of Urology, Seoul, REPUBLIC OF KOREA - 6) Ulsan University Hospital, Departments of Urology, Ulsan, REPUBLIC
OF KOREA - 7) Asan Medical Center, University of Ulsan College of Medicine, Departments of Urology, Seoul,
REPUBLIC OF KOREA
PURPOSE
We investigated the clinical features of hypospadias in twin patients and to evaluate the genetic or
environmental factors affecting the development of hypospadias.
MATERIAL AND METHODS
We retrospectively reviewed the medical records of 50 male twin patients who underwent ure-
throplasty in our institution. We investigated the characteristic of mother and patient regarding
hypospadias. Small for gestational age, (SGA) was defined when the body weight (BW) was less
than 10
th
percentile of a standard BW curve.
RESULTS
Of the 50 twin patients, 20 (40%) were identical and 8 (40%) of them showed concordance of
hypospadias whereas only 1 (3.3%) of fraternal twin showed concordance (p=0.002). Fraternal
twins had a tendency to present higher ratio of posterior type of hypospadias than identical twins
(40.0% vs 15.0%, p=0.069). Between the 10 concordant and 10 discordant twins, there was no
significant difference of the mean age of maternal age at birth, distribution of accompanied dis-
eases, mean GA and placental weight. However, BW was significantly lower in discordant twin with
hypospadias (1.38 ± 0.43 vs. 2.03 ± 0.51, p=0.009). Discordant twins had higher prevalence of SGA
than concordant twins (90.2% vs. 20.0%, p=0.003). In a multivariate regression analysis, the ac-
companied congenital anomaly other than urogenital system was the only risk factor for a posterior
type hypospadias (HR = 11.39, CI 1.33-97.28, p = 0.026).
CONCLUSIONS
Although monozygotic twins have the same genetic disposition at fertilization, the environmental
factors related to low birth weight are involved in development of hypospadias in identical twins.