Twin to Twin Transfusion Syndrome: Causes, Symptoms, and Treatment
Medically reviewed by Harsha Moole, MD, Internal Medicine. Last reviewed: October 2, 2026.
What kind of doctor treats Twin to Twin Transfusion Syndrome?
TTTS is managed by a maternal fetal medicine specialist, an obstetrician with extra training in high risk pregnancy. Laser surgery is done at specialized fetal care centers, and a general obstetrician usually continues routine pregnancy care alongside the specialist. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What it is
Twin to twin transfusion syndrome, often called TTTS, is a rare problem in pregnancies with twins who share one placenta. Blood passes unevenly between the babies through shared blood vessels in the placenta: one baby gets too much blood and the other too little.
TTTS happens when twins share a single placenta and blood flows unevenly between them. The recipient twin receives extra blood and can develop too much amniotic fluid, while the donor twin may have too little fluid and grow more slowly. It only happens when twins share one placenta.
Symptoms
Her belly may grow much faster than expected, and she may feel sudden pressure, back pain, or early contractions. Ultrasound may show one baby with too much fluid and one with too little.
Causes and who gets it
TTTS is not caused by anything the mother does and cannot be prevented. It happens only when identical twins share one placenta, where blood vessels can connect the babies' circulation and flow unevenly, ranging from mild to severe.
How doctors diagnose it
Doctors usually find TTTS during a routine prenatal ultrasound, which can show whether the twins share a placenta and whether one baby has too much fluid while the other has too little. Suspected cases are referred to a maternal fetal medicine specialist.
Treatment
Treatment depends on severity and how far along the pregnancy is. Mild cases may be watched with frequent ultrasounds. For severe cases, a common treatment is fetoscopic laser surgery, which seals the connecting blood vessels on the placenta. Other options include removing extra fluid, medicines, or early delivery.
When to see a doctor
Call a doctor right away if the belly grows much faster than expected, if there is sudden pressure or pain, or if the baby moves less. Anyone carrying twins should attend all prenatal visits, because early detection makes a difference.
Common questions
Can TTTS be prevented?
No. Parents cannot prevent TTTS, and it is not caused by anything the mother does. Finding it early through regular prenatal ultrasounds is the best way to improve the chances of a good outcome.
Does TTTS mean the babies are identical?
Yes. TTTS only happens when twins share one placenta, and twins who share a placenta are almost always identical. Not all identical twins share a placenta, so not all identical twin pregnancies are at risk.
Can both babies survive TTTS?
Many pregnancies affected by TTTS have at least one surviving baby, and some have two, especially when the condition is found and treated early. Outcomes vary a lot from case to case, so it is best to ask the care team about the specific situation.
How is a direct primary care or concierge doctor involved?
A direct primary care doctor, who is paid a flat monthly fee instead of billing insurance, or a concierge doctor, who usually charges more and often works with insurance, does not treat TTTS directly. These doctors can help before and after pregnancy by managing general health, answering questions, and coordinating care. When TTTS is suspected, they would refer the patient promptly to an obstetrician or a maternal fetal medicine specialist.
Sources
- NIH Genetic and Rare Diseases Information Center - Twin-to-twin transfusion
- MedlinePlus - Twin-to-twin transfusion syndrome
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
