DiseasesDB = 29907
MedlinePlus = 001286
eMedicineSubj = ped
eMedicineTopic = 1136
Hypospadias is a
birth defectof the urethrain the malethat involves an abnormally placed urinary meatus(opening). Instead of opening at the tip of the glans of the penis, a hypospadic urethra opens anywhere along a line (the "urethral groove") running from the tip along the underside (ventral aspect) of the shaft to the junction of the penis and scrotumor perineum. A distal hypospadias may be suspected even in an uncircumcised boy from an abnormally formed foreskinand downward tilt of the glans.
The urethral meatus opens on the
glans penisin about 50-75% of cases; these are categorized as "first degree" hypospadias. "Second degree" (when the urethra opens on the shaft), and "third degree" (when the urethra opens on the perineum) occur in up to 20 and 30% of cases respectively. The more severe degrees are more likely to be associated with chordee, in which the phallus is incompletely separated from the perineum or is still tethered downwards by connective tissue, or with undescended testes ( cryptorchidism).
Hypospadias are among the most common birth defects of the male genitalia (second to
cryptorchidism), but widely varying incidences have been reported from different countries, from as low as 1 in 4000 to as high as 1 in 125 boys.
There has been some evidence that the incidence of hypospadias around the world has been increasing in recent decades. In the United States, two surveillance studies reported that the incidence had increased from about 1 in 500 total births (1 in 250 boys) in the 1970s to 1 in 250 total births (1 in 125 boys) in the 1990s. Although a slight worldwide increase in hypospadias was reported in the 1980s, studies in different countries and regions have yielded conflicting results and some registries have reported decreases.
Most occurences of hypospadias are sporadic, without inheritance or family recurrence; however, it can result from genetics (a pericentric inversion of chromosome 16). For most cases, no cause can be identified though a number of hypotheses related to inadequate
androgeneffect, or environmental agents interfering with androgen effect, have been offered. Among the suspected environmental agents have been various chemicals, sometimes termed endocrine disruptors, that interact with steroid receptors. Putative endocrine disruptors include phthalates, DDT, and polychlorinated biphenyls. A recent questionnaire study of mothers who bore infants with hypospadias reported fivefold higher risk association with vegetarian diet(with plant phytoestrogens the hypothetical link) during pregnancy, and weaker associations with ironsupplementation or influenzaduring early pregnancy.cite journal |author=North K, Golding J |title=A maternal vegetarian diet in pregnancy is associated with hypospadias. The ALSPAC Study Team. Avon Longitudinal Study of Pregnancy and Childhood |journal=BJU Int. |volume=85 |issue=1 |pages=107–13 |year=2000 |pmid=10619956 |doi=10.1046/j.1464-410x.2000.00436.x |url=http://www.blackwell-synergy.com/toc/bju/85/1] The associations are as yet uncorroborated by additional surveys or other methods.
testosterone, converted in the genital skin to dihydrotestosterone, causes migration of skin fibroblasts to fully enclose the urethral groove in fetal males, normally resulting in an enclosed penile urethra by the second trimester of pregnancy. Failure of adequate prenatal androgeneffect is therefore thought to be involved in many cases, making hypospadias a very mild form of intersex(under- virilizationof a genetic male). Since postnatal androgen deficiency can only be demonstrated in a minority of cases, it has been proposed that transient deficiency of testosterone can occur during critical periods of fetal genital development, due to elevation of anti-müllerian hormoneor more subtle degrees of pituitary-gonadal dysfunction. More recently, abnormalities of transcription factors have been proposed.
In animals, several
teratogenic drugs or chemicals can cause hypospadias by interfering with androgenaction in the embryo. Speculation that environmental agents-- endocrine disruptors-- might be interfering with human hormone systems has not been proven. The agents that have caused hypospadias in a small number of boys have been maternal use of synthetic progestins and finasteridein the first two trimesters of pregnancy. In 2008, it was suggested that maternal use of diethylstilbestrol, a synthetic estrogen, resulted in a 20-fold increase in prevalence of hypospadiascite journal |author=Klip H, Verloop J, van Gool JD, Koster ME, Burger CW, van Leeuwen FE |title=Hypospadias in sons of women exposed to diethylstilbestrol in utero: a cohort study |journal=Lancet |volume=359 |issue=9312 |pages=1102–7 |year=2002 |pmid=11943257 |doi=10.1016/S0140-6736(02)08152-7 |url=] although a followup study showed the risk, though present, to be much lesser. cite journal |author=Brouwers MM, Feitz WF, Roelofs LA, Kiemeney LA, de Gier RP, Roeleveld N |title=Hypospadias: a transgenerational effect of diethylstilbestrol? |journal=Hum. Reprod. |volume=21 |issue=3 |pages=666–9 |year=2006 |pmid=16293648 |doi=10.1093/humrep/dei398 |url=]
In a minority of cases a postnatal deficiency of, or reduced sensitivity to,
androgens ( testosteroneand dihydrotestosterone) can be demonstrated. These are often associated with a chordee, and in severe cases a residual perineal urogenital opening and small phallus. This combination of birth defects is referred to as pseudovaginal perineoscrotal hypospadiasand is part of the spectrum of ambiguous genitalia. Treatment with testosterone postnatally does not close the urethra.
Genetic factors are likely involved in at least some cases, as there is about a 7% familial recurrence risk.
Rare iatrogenic urethral injuries similar to hypospadias after procedures such as surgery, catheterization, or circumcision have been reported.
First degree hypospadias are primarily a cosmetic defect and have little effect on function except for direction of the urinary stream. If uncorrected, a second or third degree hypospadias can make male urination messy, necessitate that it be performed sitting, impair delivery of semen into the vagina (possibly creating problems with
fertility), or interfere with erections. In developed countries, most hypospadias are surgically repaired in infancy. Surgical repair of first and second degree hypospadias is nearly always successful in one procedure, usually performed in the first year of life by a pediatric urologistor a plastic surgeon.
When the hypospadias is third degree, or there are associated birth defects such as
chordeeor cryptorchidism, the best management can be a more complicated decision. A karyotypeand endocrine evaluation should be performed to detect intersex conditions or hormone deficiencies. If the penis is small, testosteroneor human chorionic gonadotropin(hCG) injections may be given to enlarge it prior to surgery.
Surgical repair of severe hypospadias may require multiple procedures and mucosal grafting. Preputial skin is often used for grafting and circumcision should be avoided prior to repair. In a minority of patients with severe hypospadias surgery produces unsatisfactory results, such as
scarring, curvature, or formation of urethral fistulas, diverticula, or strictures. A fistula is an unwanted opening through the skin along the course of the urethra, and can result in urinary leakage or an abnormal stream. A diverticulum is an "outpocketing" of the lining of the urethra which interferes with urinary flow and may result in post-urination leakage. A stricture is a narrowing of the urethra severe enough to obstruct flow. Reduced complication rates even for third degree repair (e.g., fistula rates below 5%) have been reported in recent years from centers with the most experience, and surgical repair is now performed for the vast majority of infants with hypospadias.
Because of the difficulties and lower success rates of surgical repair of the most severe degrees of under
virilization, some of these genetically male but severely undervirilized infants have been assigned and raised as girls, with feminizing surgical reconstruction. Opinion has shifted against this approach in the last decade because adult sexual function as a female has often been poor, and development of a male gender identitydespite female sex assignmentand rearing, has occurred in some XY children after reassignment for a more severe type of genital birth defect, cloacal exstrophy.
Associated birth defects
Mild hypospadias most often occurs as an isolated birth defect without detectable abnormality of the remainder of the reproductive or endocrine system. However, a minority of infants, especially those with more severe degrees of hypospadias will have additional structural anomalies of the genitourinary tract. Up to 10% of boys with hypospadias have at least one undescended
testis, and a similar number have an inguinal hernia. An enlarged prostatic utricleis common when the hypospadias is severe (scrotal or perineal), and can predispose to urinary tract infections, pseudo-incontinence, or even stone formation.
A much rarer and unrelated type of urethral malformation is an
epispadias. This is not a problem of the urethral groove or meatus, but a failure of midline penile fusion much earlier in embryogenesis. An isolated opening of the dorsal ("top") side of the penis is rare, and most of these children have much more severe defects, involving a small and bifid phallus with bladder exstrophyor more severely, cloacal exstrophyinvolving the entire perineum. The cause of this defect of early embryogenesis is unknown but does not involve androgens.
bladder exstrophy, cloacal exstrophy
perineal urethra, pseudovaginal perineoscrotal hypospadias
ambiguous genitalia, intersex, intersex surgery
androgen insensitivity syndrome
*cite journal |author=Austin PF, Siow Y, Fallat ME, Cain MP, Rink RC, Casale AJ |title=The relationship between müllerian inhibiting substance and androgens in boys with hypospadias |journal=J. Urol. |volume=168 |issue=4 Pt 2 |pages=1784–8; discussion 1788 |year=2002 |pmid=12352359 |doi=10.1097/01.ju.0000023680.64155.5c |url= |doi_brokendate=2008-10-03
*cite journal |author=Patel RP, Shukla AR, Snyder HM |title=The island tube and island onlay hypospadias repairs offer excellent long-term outcomes: a 14-year followup |journal=J. Urol. |volume=172 |issue=4 Pt 2 |pages=1717–9; discussion 1719 |year=2004 |pmid=15371798 |doi= 10.1097/01.ju.0000138903.20136.22|url=http://linkinghub.elsevier.com/retrieve/pii/00005392-200410001-00033
*cite journal |author=Retik AB, Atala A |title=Complications of hypospadias repair |journal=Urol. Clin. North Am. |volume=29 |issue=2 |pages=329–39 |year=2002 |pmid=12371224 |doi= 10.1016/S0094-0143(02)00026-5|url=
*cite journal |author=Shukla AR, Patel RP, Canning DA |title=Hypospadias |journal=Urol. Clin. North Am. |volume=31 |issue=3 |pages=445–60, viii |year=2004 |pmid=15313054 |doi=10.1016/j.ucl.2004.04.020 |url=
* [http://www.drhuhc.org/services/urology/ Adult Reconstructive Urology--Urethral stricture after childhood hypospadias repair]
* [http://ehpnet1.niehs.nih.gov/docs/1999/107p297-302paulozzi/abstract.html International Trends in Rates of Hypospadias and Cryptorchidism]
* [http://www.heainfo.org The Hypospadias and Epispadias Association, for families affected by these congenital penile differences.]
* [http://www.hypospadias-emotions.com Review of scientific papers describing the physical and psychological implications and consequences of hypospadias.]
* [http://img220.imageshack.us/img220/5301/hypospadiasja3vn0.jpgUretheral graft technique (Camillo Il Grande)]
* [http://www.the-european-institute-ugrs.com The-European-Institute-UGRS.com]
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Look at other dictionaries:
hypospadias — [ ipɔspadjas ] n. m. • 1842; n. f. 1819 ; gr. hupospadias, de hupo (cf. hypo ) et span « déchirer » ♦ Pathol. Malformation de l urètre caractérisée par un méat urinaire situé à la face inférieure de la verge ou même au niveau du périnée (⇒… … Encyclopédie Universelle
Hypospadias — Hy po*spa di*as, n. [NL., fr. Gr. ypo beneath + spa n to draw, tear.] (Med.) A deformity of the penis, in which the urethra opens upon its under surface. [1913 Webster] … The Collaborative International Dictionary of English
Hypospadias — A birth defect of the penis involving the urethra (the transport tube leading from the bladder to discharge urine outside the body). The urethra in the male normally travels through the full length of the penis so that the stream of urine comes… … Medical dictionary
Hypospadias — Pénis en érection présentant une hypospadias. L’hypospadias est une malformation du fœtus masculin, qui se manifeste par l ouverture de l urètre dans la face inférieure du pénis au lieu de son extrémité. Ce type de malformation semble en… … Wikipédia en Français
hypospadias — A birth defect in which the opening of the urethra (the tube through which urine leaves the body) is not in its normal place. In males with hypospadias, the urethra opens on the underside of the penis or between the anus and the scrotum. In… … English dictionary of cancer terms
hypospadias — n. a congenital abnormality in which the opening of the urethra is on the underside of the penis: either on the glans penis (glandular hypospadias), at the junction of the glans with the shaft (coronal hypospadias), or on the shaft itself (penile … The new mediacal dictionary
hypospadias — noun Etymology: New Latin, from Greek, man with hypospadias, from hypo + spadias, from spad , spas something torn, from span to tear, pluck off Date: circa 1855 an abnormality of the penis in which the urethra opens on the undersurface … New Collegiate Dictionary
hypospadias — [ˌhʌɪpəʊ speɪdɪəs] noun Medicine a congenital condition in males in which the opening of the urethra is on the underside of the penis. Origin C19: from Gk hupospadias person having hypospadias … English new terms dictionary
hypospadias — noun A birth defect of the male urethra that involves an abnormally placed urinary meatus … Wiktionary
hypospadias — (i po spa di as ) s. m. Terme de médecine. Vice de conformation des parties génitales du sexe masculin, consistant en ce que l urètre s ouvre au dessous de la verge, en un point quelconque. ÉTYMOLOGIE En grec, terme dérivé du mot signifiant au … Dictionnaire de la Langue Française d'Émile Littré