Pygopagus


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Pygopagus

 

a developmental defect in which conjoined twins are united in the sacral region. The individuals forming a pygopagus are believed to be either females or hermaphrodites. The Czech pygopagus Rosa and Josefa Blažek lived 42 years (1878–1920) in good health. Modern medicine corrects this defect surgically.

References in periodicals archive ?
Out of the 30 pygopagus cases reported worldwide, 26 were female and only four were male.
Conjoined twins represent an uncommon congenital malformation, with an estimated incidence of 1: 50,000-1: 100,000,1 and approximate 75 Percent of cases are females.2,3 Usually, conjoined twins are classified according to the most prominent site of conjunction: thorax (thoracopagus) 40 Percent , abdomen (xiphopagus and omphalopagus) 33 Percent , sacrum (pygopagus) 18 Percent , pelvis (ischiopagus) 6 Percent , and craniopagus (1-2 Percent).3,4
The more common types of conjoined twins include the thoracopagus type where the fusion is anterior, at the chest, and involves the heart (35%); the omphalopagus type where the fusion is at the mid-trunk (30%); the pygopagus type where there is a posterior union involving the rump (19%); the parapagus type, with a lateral fusion of the lower half of the body extending upwards (5%); and combination types.
Conjoined twins are classified according to the most prominent site of conjunction: thorax (thoracopagus); abdomen (omphalopagus); sacrum (pygopagus); pelvis (ischiopagus); skull (cephalopagus), side by side (parapagus) and back (rachipagus).