Twin to twin transfusion syndrome: Questions About Specialist Monitoring

Twin to twin transfusion syndrome, usually shortened to TTTS, is a complication that can develop when twins share a placenta. Unequal blood flow through connecting placental vessels affects the babies differently. It needs specialist assessment and cannot be diagnosed from pregnancy symptoms or the size of your bump alone.

Understand the basic problem

The baby described as the donor receives too little blood, while the recipient receives too much. This can affect urine production, the fluid surrounding each baby and the strain on the recipient’s heart.

These labels describe the circulation problem. They do not mean either baby has done something wrong. Our shared placenta guide explains why this arrangement is monitored more closely from the second trimester.

Know what ultrasound is checking

In twins with separate sacs, the team looks for a pattern of too little fluid around one baby and too much around the other. Assessment can also include the babies’ bladders, blood flow and heart findings.

A difference in estimated weight alone does not diagnose TTTS. The specialist needs to assess the whole pattern and determine how severe the condition is. The twin growth scan guide helps distinguish size monitoring from these additional checks.

For a shared placenta, routine ultrasound surveillance is generally offered every two weeks from 16 weeks until birth. If a concern is found, the plan may become more frequent. Do not skip a booked scan because you have no symptoms.

Ask what a referral means now

If TTTS is suspected or diagnosed, referral to a specialist fetal medicine centre allows a more detailed assessment and treatment discussion. Ask whether the diagnosis is established, which findings determine its stage and how quickly the next decision is needed.

You can request a written explanation and ask the clinician to draw the placental connections. Bring someone to help remember the discussion if that would be useful.

Understand that treatment is individual

Selected cases can be monitored closely, while others may need a procedure. Fetoscopic laser treatment aims to seal the connecting vessels involved in the imbalance. Whether it is appropriate depends on factors including the pregnancy stage, severity and technical findings.

Ask about the expected benefits, procedure risks, alternatives and monitoring afterwards. Treatment cannot promise that both babies will avoid every complication. Advice for another family’s pregnancy may not apply to yours.

Keep the contact plan clear

Before leaving, know where to go for new pain, leaking fluid, bleeding or other urgent concerns. If symptoms change while you are waiting for a referral, contact maternity care rather than waiting for the appointment letter. The specialist plan should include both scheduled monitoring and help between visits.