Korean Journal of Obstetrics and Gynecology (대한산부인과학회지), Vol.44(1) : 198~201, 2001
Korean Journal of Obstetrics and Gynecology (대한산부인과학회지)
Sirenomelia, characterised by a complete or incomplete fusion of the lower extremities, is a severe form of caudal defect affecting 1.5-4.2 in 100,000 births. Most cases of sirenomelia die within 5days after birth and are associated with abnormalities such as renal agenesis, urinary tract agenesis, single umbilical artery, etc. Third trimester ultrasonographic diagnosis is usually impaired by severe oligohydramnios whereas the amount of amniotic fluid may be sufficient to allow diagnosis in the early second trimester. We report a case of sirenomelius at 12 weeks of gestation using prenatal transvaginal ultrasonography.