What is Conjoined Twins?

Conjoined twins are twins who are physically attached to each other in the womb, and as a result, are attached at birth as well. This condition was first noted during the Stone Age. Scientists believe that conjoined twins occur either through a process known as fission or fusion. This occurs when a single-egg twin pregnancy splits more than 13 days after fertilization. These twins share one placenta and one amniotic sac. Conjoined twins occur more commonly in females than males, with a ratio of 3 to 1. Dealing with a pregnancy with conjoined twins can be complicated, and so requires a team of professionals to manage it effectively.

What Causes Conjoined Twins?

The main theories around why conjoined twins occur suggest two possibilities: a partial split of a single fertilized egg, or two separate eggs merging together again after initially splitting. These theories can generally explain the characteristics observed in conjoined twins, however, they don’t have explanations for every possible instance of conjoined twins.

There are two broad categories of conjoined twins: those joined at the front, side, or bottom (referred to as non-dorsally conjoined twins) and those joined at the back (referred to as dorsally conjoined twins).

Non-dorsally conjoined twins often have a single shared umbilical cord and their bodies are typically merged at some of their organs. Dorsally conjoined twins usually have two separate umbilical cords and their internal organs are mostly separate from each other. It’s thought that non-dorsally conjoined twins result from a change in the orientation or interaction of the initial cells that were meant to form a single individual. On the other hand, dorsally conjoined twins may occur because of two originally separate twins merging back together.

Risk Factors and Frequency for Conjoined Twins

Conjoined twins are a rare occurrence, happening in about one out of every 50,000 to 200,000 births. Sadly, about 60 percent of conjoined twins are stillborn. However, having conjoined twins doesn’t increase the risk of it happening again in future pregnancies. It’s tough to get precise numbers across different countries and ethnic groups because not all cases are reported. Additionally, conjoined twins occur more often in females, with a ratio of 3 female cases for every male one.

Signs and Symptoms of Conjoined Twins

A pregnancy with conjoined twins might first be suspected when a woman’s uterus measures larger than the norm for her stage of pregnancy. Thanks to the development in imaging technology, most instances of conjoined twins are currently identified early on, often using prenatal ultrasound scans.

Testing for Conjoined Twins

Ultrasound scans are usually the best way to identify any potential issues early in a pregnancy. Some of these might include the type of join between twins, any birth defects, and understanding different types of tissues. If these tests find anything, they should be used to guide further testing after the baby is born, using a technique called magnetic resonance imaging, or MRI.

Moreover, modern technology like 3D printing can help doctors prepare for any surgeries that might be needed to separate conjoined twins, for example. Always remember, early and regular medical evaluations during pregnancy can pinpoint complications for timely interventions.

Treatment Options for Conjoined Twins

Conjoined twins who are born alive can typically be sorted into two groups: those who can be surgically separated and those who cannot. This decision is made through a combined effort of various medical professionals using advanced imaging techniques and multiple examinations. Twins who share crucial organs can usually not be separated, because doing so could potentially cause one or both of the twins to die. This situation raises ethical questions when it comes to the surgical treatment of conjoined twins, but ultimately, the final decision belongs to the parents. In some instances, the ethical review board of the hospital might need to be involved.

The surgical process involves identifying the anatomical relationship of the connection between the twins. The surgical team uses three-dimensional modeling and simulations to make informed decisions about the surgery. Techniques like using tissue expanders before surgery are beneficial as they help solve problems related to closing the abdominal wall after surgery. It is generally recommended to conduct at least one practice surgery before the actual procedure, as this can improve the outcome for the conjoined twins.

During medical treatment, it’s essential to consider certain factors relating to drug processing and metabolism. Since the twins share a circulatory system, the way their bodies distribute and remove drugs can vary significantly.

Conjoined twins are a rarity, and they can be specifically identified during pregnancy scans. However, the appearance of these twins could be confused with other medical conditions that also show unusual results on ultrasound scans. These conditions could be cystic hygroma, teratoma, and lymphangioma.

What to expect with Conjoined Twins

The outlook for conjoined twins is generally not very positive, with an overall survival rate of 7.5%. Even after surgical separation, only 60% of cases survive. Various approaches could potentially improve their chances, such as monitoring while still in the womb, post-birth surgery if necessary, using tissue expansion techniques during surgery, and transplanting vital organs from a donor if the twins share these organs.

Possible Complications When Diagnosed with Conjoined Twins

Given the complicated situation of the pregnancy, there is a high probability that the twins will not survive inside the uterus. After birth, the twins’ complex physical conformation may put them at risk of dying. If separation surgery is considered, complications could take place. These might involve failure of essential organs, skin problems, infections after surgery, bleeding, accidental harm to internal organs or blood vessels, or not being able to complete the operation.

Common Risks of Separation Surgery:

Organ failure
Skin defects
Surgical infection
Bleeding
Injury to internal organs and/or blood vessels
Failure to complete the procedure

Preventing Conjoined Twins

Conjoined twins bring about not just physical, but emotional and social challenges as well. The decision to surgically separate them can be ethically tricky, particularly if one twin benefits more from the surgery than the other. Making their own identity can also be tough for them, and they can experience reactions tied to their twin status.

For this reason, it’s vital that social workers are part of the team caring for conjoined twins. They can assist in coach and enlighten family members about the issues and difficulties conjoined twins might face. Additionally, social workers can help provide clear explanations regarding their generally poor health outlook. This information can be essential in helping the family care for the twins more effectively.