In brief — the direct answer
Twin-to-Twin Transfusion Syndrome (TTTS) is a rare and life-threatening condition that only affects identical twins sharing a single placenta (MCDA). It occurs when blood vessels on the placenta connect the two babies' circulations in an unbalanced way. One twin (the donor) pumps blood to the other (the recipient). Without intervention, the donor becomes anemic and small with no amniotic fluid, while the recipient becomes overloaded with blood, develops heart failure, and produces excessive amniotic fluid. At the MFM Unit, we are the regional leaders in treating TTTS through advanced laser surgery.
What is Twin-to-Twin Transfusion Syndrome (TTTS)?
TTTS is not a problem with the babies themselves, but a problem with the placental 'plumbing.'
- The Donor: Becomes dehydrated. Their kidneys stop producing urine, and they soon have no amniotic fluid (oligohydramnios), making them appear 'stuck' against the uterine wall.
- The Recipient: Receives too much blood. Their heart struggles to pump the extra volume, and they compensate by producing huge amounts of urine/amniotic fluid (polyhydramnios), which stretches the mother's uterus and causes discomfort.
Who is at risk?
TTTS only occurs in Monochorionic (shared-placenta) twins. It typically develops between 16 and 26 weeks of pregnancy. It is not caused by anything the mother did and cannot be prevented with diet or lifestyle changes; it is a technical event of placental development.
How we diagnose it
We use the Quintero Staging System to categorize severity:
- Stage I: Imbalance of fluid (excess in recipient, little in donor), but the donor's bladder is still visible.
- Stage II: The donor's bladder is no longer visible on ultrasound.
- Stage III: Abnormal Doppler blood flow in the brains or cords of either baby.
- Stage IV: The recipient twin shows signs of heart failure (hydrops).
- Stage V: Death of one or both twins.
What does management involve?
The definitive treatment for TTTS is Fetoscopic Laser Photocoagulation (FLPC):
- The Laser: A tiny camera (fetoscope) is inserted into the mother's uterus. We identify the connecting vessels on the placenta and use a laser to 'seal' them, separating the circulations.
- Amnioreduction: At the end of the surgery, we drain the excess fluid from the recipient’s sac to reduce the risk of premature labor.
- Success Rates: In expert hands, at least one baby survives in 85-90% of cases, and both babies survive in about 60-70% of cases.
What are the outcomes?
Early intervention is the key to a healthy outcome.
- Without Surgery: The mortality rate for TTTS is over 90%.
- With Surgery: The risk of long-term disability is significantly reduced, and most survivors go on to live healthy lives.
- Monitoring Post-Surgery: We continue to scan every week for the remainder of the pregnancy to ensure the circulations remain stable.
When to see a subspecialist
You must seek help immediately if you experience 'Red Flag' symptoms:
- Sudden Growth: Your belly suddenly feels much larger or tighter over 24-48 hours.
- Abdominal Pain and difficulty breathing due to the pressure.
- Reduced Movement of the babies.
Our fetal surgery team, led by Dr. Werner Diehl, is available 24/7 for TTTS emergencies. We provide the highest level of surgical expertise in the UAE to save shared-placenta twins.
Questions to ask your doctor
References & Clinical Guidelines
- ISUOG Practice Guidelines: role of ultrasound in twin pregnancy
- Twin-Twin Transfusion Syndrome (Consult Series No. 39)
- Endoscopic Laser Surgery versus Serial Amnioreduction for Severe Twin-to-Twin Transfusion Syndrome (Eurofetus trial)
- Management of Monochorionic Twin Pregnancy (Green-top Guideline No. 51)