Introduction
Conjoined twins with monoamniotic placenta result from the incomplete splitting of the embryonic disc at 13th to 15th day of gestation. Conjoined twins represent a unique structural defect of monozygotic monoamniotic twins. Earliest described conjoined twins (the Maids of Biddenden in England) date back to 1100 AD.1 Conjoined twins are inappropriately named as “Siamese twins” in relation to twin brothers Chang and Eng, born in Siam (Thailand) in 1811.2 We report a rare case of Cranio-thoraco-omphalopagus twins born to a primigravida mother at thirty weeks period of gestation.
Case report
28 years old primigravida mother was diagnosed to have a twin pregnancy during her first trimester ultrasonic examination. She was lost to follow up. She presented in early third trimester and on evaluation was found to have a conjoined twin pregnancy. Babies were born by a lower segment caesarean section with a birth weight of 3 kg. The twin neonates had a single fetal heart on examination and were joined at their head, chest, and abdomen. The conjoined twins had a single face with two craniums, two pairs of legs, arms and ears (Figs. 1 and 2). The babies died a few minutes after birth. Post-mortem examination was refused by parents.
Fig. 1.
Conjoined twins with a single face and joined thorax and abdomen.
Fig. 2.
Radiograph of the conjoined twins shows fused cranium.
Discussion
Conjoined twins are born because the non-separated parts of the otherwise normal twins remain fused throughout the period of development. The incidence of conjoined twins is between 1 in 50,000 – 1,25,000 births, and 70%–80% of these cases are females. Approximately 18%–40% are joined at the chest (thoracopagus), 10%–34% at the anterior abdominal wall (xiphopagus or omphalopagus), 18% at the buttocks (pygopagus), 6% at the ischium (ischiopagus), and 2%–6% at the head (craniopagus). Forty percent of conjoined twins are stillborn, and an additional 35% survive only one day. The incidence of conjoined twins has declined after the advent of ultrasound guided maternal screening.
We have presented this case owing to the rarity of the case and to emphasize the importance of timely antenatal screening. There have been case reports of aborted fetuses with this presentation.3,4 There is only a single case report of a live born Cranio-thoraco-omphalopagus in the world literature5 and we are reporting second such case.
Conflicts of interest
The case report was presented as poster in NEOCON-2010.
References
- 1.Guttmacher A.F. Biographical notes on some famous conjoined twins. Natl Found. 1967;3:10–17. [Google Scholar]
- 2.Daniels W.B. The Siamese twins: some observations on their life, last illness and autopsy. Med Ann Dist Columbia. 1963;32:273–277. [PubMed] [Google Scholar]
- 3.Singh Yoginder, Kathpalia S.K., Bal H., Arif N.K. Early prenatal diagnosis in a case of conjoined twin with Craniopagus and Thoraco-omphalopagus. MJAFI. 2012;68(4):381–382. doi: 10.1016/j.mjafi.2011.12.005. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Sabih D., Ahmad E., Sabih A., Sabih Q. Ultrasound diagnosis of cephalopagus conjoined twin pregnancy at 29 weeks. Biomed Imaging Interv J. 2010;6(4):e38. doi: 10.2349/biij.6.4.e38. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Gerber Aaron H., Skala Robert, Homberg Roy. South Med J. 1969;62(8):798. doi: 10.1097/00007611-196908000-00018. [DOI] [PubMed] [Google Scholar]