A woman gave birth to conjoined twins in Odisha on 11 April morning. Born at a private nursing home in the Kendrapara districts, the twin girls are joined at the chest and abdomen. Such twins are popularly known as Siamese twins — after brothers Chang and Eng Bunker (1811–1874) were born with the condition in Siam — and is understood as a rare condition.
The girls’ condition deteriorated after birth, but doctors later said they were stable. Both the babies are healthy at present. The rare condition that occurs once in 49,000 to 1,89,000 births is known to affect births of girls more than boys in the ratio 3:1. Science has not deciphered the cause fully even though it is widely believed that fission, in which the fertilised egg splits partially, is the reason behind such births.
“Conjoined twins are a rare congenital anomaly. The twin sisters share a single body, three arms and two legs. They are eating with two mouths and breathing with two noses. After an ultrasound of the babies, details of the abnormality will be known,” Dr Debasish Sahoo, the pediatric consultant at the district headquarters hospital said.
The babies, delivered by caesarean section, were born to Ambika and Umakant Parida, residents of Kani village in Rajnagar area. The father of the babies has sought the state government’s help for the treatment of the twins.
In 2017, the Odisha government had borne the cost of the successful separation and treatment of conjoined twins Jaga and Kalia at the All India Institute of Medical Sciences (AIIMS) in Delhi.
Ambika and Umakant Parida’s twins were shifted from the private nursing home to the district headquarters hospital after their birth, and later to the Sardar Vallabhbhai Patel Postgraduate Institute of Paediatrics in Cuttack for specialised care and treatment after their condition deteriorated. Their condition is now stable.
Dr Sahoo said that this kind of abnormal birth has now decreased as people are more aware. “However, in rural areas, people still do not take medicines on time. They stop taking folic acid and other medicines, and they do not go for ultrasound or anomaly detection scans at later stages,” he said.
Notably, the district administration of tribal-dominated Sundargarh district in Odisha launched a scheme called, ‘Matrujyoti’ in 2020 for the wellbeing of pregnant women and foetuses through regular health check-ups. Under the antenatal programme, four free ultrasound examinations and other tests are done.
Types of conjoined twins
Conjoined twins are typically classified by the point at which their bodies are joined. The most common types of conjoined twins are:
- Thoraco-omphalopagus (28% of cases): Two bodies fused from the upper chest to the lower chest. These twins usually share a heart, and may also share the liver or part of the digestive system.
- Thoracopagus (18.5%): Two bodies fused from the upper chest to lower belly. The heart is always involved in these cases. As of 2015, separation of a genuinely shared heart has not offered survival to two twins; a designated twin may survive if allotted the heart, sacrificing the other twin.
- Omphalopagus (10%): Two bodies fused at the lower abdomen. Unlike thoracopagus, the heart is never involved in these cases; however, the twins often share a liver, digestive system, diaphragm and other organs.
- Parasitic twins (10%): Twins that are asymmetrically conjoined, resulting in one twin that is small, less formed, and dependent on the larger twin for survival.
- Craniopagus (6%): Fused skulls, but separate bodies. These twins can be conjoined at the back of the head, the front of the head, or the side of the head, but not on the face or the base of the skull.
- Cephalopagus: Two faces on opposite sides of a single, conjoined head; the upper portion of the body is fused while the bottom portions are separate. These twins generally cannot survive due to severe malformations of the brain. Also known as janiceps (after the two-faced Roman deity Janus) or syncephalus.
- Syncephalus: One head with a single face but four ears, and two bodies.
- Cephalothoracopagus: Bodies fused in the head and thorax. In this type of twins, there are two faces facing in opposite directions, or sometimes a single face and an enlarged skull.
- Xiphopagus: Two bodies fused in the xiphoid cartilage, which is approximately from the navel to the lower breastbone. These twins almost never share any vital organs, with the exception of the liver. A famous example is Chang and Eng Bunker.
- Ischiopagus: Fused lower half of the two bodies, with spines conjoined end-to-end at a 180° angle. These twins have four arms; one, two, three or four legs; and typically one external set of genitalia and anus.
- Omphalo-Ischiopagus: Fused in a similar fashion to ischiopagus twins, but facing each other with a joined abdomen akin to omphalopagus. These twins have four arms, and two, three, or four legs.
- Parapagus: Fused side by side with a shared pelvis. Twins that are dithoracic parapagus are fused at the abdomen and pelvis, but not the thorax. Twins that are diprosopic parapagus have one trunk and two faces. Twins that are dicephalic parapagus have one trunk and two heads and have two (dibrachius), three (tribrachius), or four (tetrabrachius) arms.
- Craniopagus parasiticus: Like craniopagus, but with a second bodiless head attached to the dominant head.
- Pygopagus or Iliopagus: Two bodies joined at the pelvis.
- Rachipagus: Twins joined along the back of their bodies, with fusion of the vertebral arches and the soft tissue from the head to the buttocks.
Conditions 6-15 are rarer.