Using Lasers to treat Twin-to-Twin TransfusionSyndrome
- incisionary
- Dec 28, 2025
- 3 min read
Updated: Dec 29, 2025
Twin-to-Twin Transfusion Syndrome, or TTTS, is one of the most dangerous
complications that can happen in identical twin pregnancies when both babies share a single
placenta. In these pregnancies, the twins are connected by placental blood vessels. Sometimes, those connections allow blood to flow unevenly from one twin to the other. One baby ends up doing most of the donating, while the other receives more blood than their body can handle. Without proper treatment, this imbalance can quickly become life-threatening for both fetuses.
For a long time, doctors could only manage the effects of TTTS rather than fix the cause.
That changed with the development of fetoscopic laser ablation, a minimally invasive fetal
surgery that directly targets the abnormal blood vessels inside the placenta. Today, it is
considered the most effective first-line treatment for moderate to severe cases of TTTS.
The procedure usually takes place between 16 and 26 weeks of pregnancy. Using the
guidance of ultrasounds, surgeons make a small incision in the mother’s abdomen and insert a thin camera called a fetoscope into the uterus. The camera allows them to see the surface of the placenta in real time. From there, the surgeon carefully maps out the blood vessels that connect the twins’ circulations. Once the problematic vessels are identified, laser energy is used to seal them off, separating the twins’ blood supply so each baby can rely on its own portion of the placenta.
One of the reasons this surgery is so challenging is because every placenta looks
different. Surgeons are working in a tight space, with limited visibility, and must identify vesselsthat are only a few millimeters wide. To help with this, researchers have been developing computer-assisted tools that improve how surgeons plan and perform the operation. Studies published through the National Institutes of Health and Wiley describe how advanced ultrasound segmentation and 3D modeling can create clearer maps of placental blood vessels before surgery even begins.
These tools allow surgeons to simulate the procedure ahead of time, choosing the safest
entry point and anticipating which vessels are most likely to cause problems. Some systems also aim to enhance fetoscopic video during surgery, making it easier to distinguish blood vessels from surrounding tissue. While many of these technologies are still being refined, they represent an important step toward making an already effective surgery even safer and more consistent.
Case studies from institutions like the Cleveland Clinic show how impactful laser
ablation can be. In many cases, signs of TTTS begin to reverse within days of the procedure.
Amniotic fluid levels stabilize, the donor twin’s bladder becomes visible again on ultrasound,
and the strain on the recipient twin’s heart decreases. Survival rates have improved dramatically compared to untreated cases, with most pregnancies resulting in the survival of at least one twin and many resulting in the survival of both.
Fetoscopic laser surgery for TTTS is a clear example of how precision, imaging, and
careful planning can change the course of a condition that was once almost always fatal. As
computer-assisted planning and visualization tools continue to improve, surgeons may be able to treat TTTS earlier, more accurately, and with better outcomes for families facing this diagnosis.
Written by Vaishnavi Kulkarni at Incisionary
References
Cleveland Clinic. (2025, May 11). Case study: Laser ablation for twin-to-twin transfusion
syndrome. Consult QD.
van der Schot, A. M., Deprest, J., Vercauteren, T., & Ourselin, S. (2022). Computer-assisted fetal laser surgery in the treatment of twin-to-twin transfusion syndrome: Recent trends and prospects.
Prenatal Diagnosis. Wiley.
National Institutes of Health. (2022). Computer-assisted fetal laser surgery in the treatment of
twin-to-twin transfusion syndrome. PubMed Central (PMC).
Mayo Clinic. (2024). Twin-to-twin transfusion syndrome.
Society for Maternal-Fetal Medicine. (2023). Management of twin-to-twin transfusion syndrome.
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