A rare case of conjoined twins presenting as dicephalus parapagus: a case report
Keywords:Anomaly scan, Conjoined twinning, Dicephalus parapagus, Embryology, High-risk pregnancy, Ultrasound
Conjoined twinning is a congenital abnormality resulting in various presentations of the fetuses in utero. It is a rare embryological developmental disorder occurring in one in 100,000 births. We present a case of conjoined twinning, which is characterized by the presence of two heads, single vertebral column and single symphysis pubis, with single genitor-urinary tract and single gastro intestinal tract. The present condition, referred to as dicephalus parapagus, is a rare entity among the conjoined twinning and has seldom positive outcomes. The mechanism of occurrence of conjoined twinning has been proposed either through fusion or fission of the embryos. In either case, surgical separation of the conjoined twins is often unsuccessful and results in increased morbidity and mortality. However, it is essential to screen for the presence of such congenital anomalies early during pregnancy, in order to terminate and provide parental counselling.
Mutchinik OM, Luna-Munoz L, Amar E, Bakker MK, Clementi M, Cocchi G, et al. Conjoined twins: a worldwide collaborative epidemiological study of the international clearinghouse for birth defects surveillance and research. Am J Med Genet C Semin Med Genet. 2011;4:274-87.
Barth RA, Filly RA, Goldberg JD, Moore P, Silverman NH. Conjoined twins: prenatal diagnosis and assessment of associated malformations. Radiol. 1990;177(1):201-7.
Logroño R, Garcia-Lithgow C, Harris C, Kent M, Meisner L. Heteropagus conjoined twins due to fusion of two embryos: report and review. Am J Med Genet. 1997;73(3):239-43.
Machin GA. Heteropagus conjoined twins due to fusion of two embryos. Am J Med Genet. 1998;78(4):388-90.
Spencer R. Theoretical and analytical embryology of conjoined twins: part I: embryogenesis. Clin Anat. 2000;13(1):36-53.
Spencer R. Conjoined twins: theoretical embryologic basis. Teratol. 1992;45(6):591-602.
Harma M, Harma M, Mil Z, Oksuzler C Vaginal delivery of dicephalic parapagus conjoined twins: case report and literature review. Tohoku J Exp Med. 2005;205(2):179-85.
Mabogunje OA, Lawrie JH. Conjoined twins in West Africa. Arch Dis Child. 1980;55(8):626-30.
Harper RG, Kenigsberg K, Sia CG, Horn D, Stern D, Bongiovi V. Xiphopagus conjoined twins: A 300-year review of the obstetric, morphopathologic, neonatal and surgical parameters. Am J Obstet Gynecol. 1980;137:617-29.
Wedberg R, Kaplan C, Leopold G, Porreco R, Resnik R, Benirschke K. Cephalothoracopagus (Janiceps) twinning. Obstet Gynecol. 1979;54:392-6.
Wilson RL, Shaub MS, Cetrulo CJ. The antepartum findinds of conjoined twins. J Clin Ultrasound. 1977;5:35-7.
Austin E, Schifrin BS, Pomerance JJ, Gans SL, Komaiko MS. The antepartum diagnosis of conjoined twins. J Pediatr Sur. 1980;15:332-4.
Turner RJ, Hankins GDV, Weinreb JC. Magnetic resonance imaging and ultrasonography in the antenatal evaluation of conjoined twins. Am J Obstet Gynecol. 1986;155:645-9.