05/02/2026
{SIAMESE TWINS ➡️ CONJOINED TWINS} 👇
Siamese twins, medically called conjoined twins, are identical twins who are physically joined together at birth. They develop from one fertilized egg and are always the same s*x.
CAUSE 👇
✓ Normally, identical twins form when one fertilized egg splits completely into two embryos.
✓ Conjoined twins occurs when the embryo fails to completely divide between day 13–15 after fertilization.
✓ Results from late and incomplete fission.
✓ Always same s*x.
✓ Not hereditary.
✓ Occurs by chance.
✓ It is not caused by drugs, food, stress, or spiritual reasons.
INCIDENCE 👇
✓ Rare: 1 in 50,000–200,000 births.
✓ Higher female predominance.
✓ High stillbirth rate.
ORGANS SHARED 👇
✓ Heart
✓ Liver
✓ Lungs
✓ Intestines
✓ Brain
✓ Spinal cord
✓ Ge***al or urinary organs
The more vital organs shared, the worse the prognosis.
TYPES OF CONJOINED TWINS (BASED ON SITE OF JOINING) 👇
1. Thoracopagus (most common)
✓ Joined at the chest
✓ Often share the heart
✓ Separation is usually very difficult.
2. Omphalopagus
✓ Joined at the abdomen
✓ May share liver or intestines
✓ Separation often possible.
3. Craniopagus
✓ Joined at the head
✓ Brains may or may not be shared
✓ Separation is high-risk but sometimes successful.
4. Pygopagus
✓ Joined at the lower back/buttocks
✓ Usually share spinal structures
✓ Good survival chance after separation.
5. Ischiopagus
✓ Joined at the pelvis
✓ May share urinary and reproductive organs.
6. Parapagus
✓ Joined side by side
✓ May share trunk and organs.
DIAGNOSIS 👇
During pregnancy:
✓ Ultrasound (as early as 1st trimester)
✓ MRI for detailed organ sharing
Signs include:
✓ Twins always facing each other
✓ Bodies not separating
✓ Shared movements.
After birth:
✓ Physical examination
✓ CT scan, MRI, Echocardiography
MANAGEMENT 👇
✓ During pregnancy
✓ Careful monitoring
✓ Counseling of parents
✓ Sometimes medical termination if survival is impossible
AFTER BIRTH 👇
✓ Immediate stabilization
✓ Breathing
✓ Feeding
✓ Infection control
✓ Assessment for separation
✓ Multidisciplinary team (surgeons, pediatricians, anesthetists).
About the naming "SIAMESE"
The name “Siamese twins” came from famous conjoined twins born in Siam (now Thailand) in the 1800s. Today, “conjoined twins” is the correct medical term.
•••RCHP OMEIZA•••
