Skip to content
knowrare
HealthSignal
Your condition community

Living with Twin-to-twin transfusion

A complication in some twin pregnancies in which blood moves unevenly from one twin to the other.

Get Signals Ask Anything

Understanding Twin-to-twin transfusion

Twin-to-twin transfusion syndrome (TTTS) is a rare condition in a twin pregnancy in which blood moves from one twin (the donor) to the other (the recipient) in the womb.

It happens only in identical twin pregnancies that share a placenta, and they may or may not share an amniotic sac. The donor twin may be born smaller, pale, anemic, and dehydrated. The recipient twin may be larger and red, with too much blood and higher blood pressure, raising the risk of heart failure.

Signs & symptoms

GARD describes how each twin can be affected:

  • Donor twin: smaller size
  • Donor twin: paleness and anemia
  • Donor twin: dehydration
  • Recipient twin: larger size
  • Recipient twin: too much blood and redness
  • Recipient twin: higher blood pressure

Not everyone has every symptom. GARD's list comes from the Human Phenotype Ontology.

Diagnosis

  1. Talk with your doctor

    Share the symptoms you've noticed, when they started and your family health history. Notes and photos can help.

  2. See a specialist

    Specialists who may be involved include allergy and immune system specialists, maternal-fetal medicine specialists and women’s reproductive health specialists.

  3. Ask which tests can help

    Your care team will decide which exams and tests can confirm the diagnosis.

  4. Connect with expert centers

    Fetal Health Foundation may keep lists of experts for this condition.

Care & treatment

Care team
Allergy and immune system specialists (allergists / immunologists); Maternal-fetal medicine specialists (pregnancy-related); Women’s reproductive health specialists (obstetricians / gynecologists)
Expert care
Expert lists: Fetal Health Foundation
Treatment
GARD doesn't list specific treatments for this condition. Your care team will tailor care to your symptoms.
Research
Clinical trials and observational studies may be options. See the research section below.

General information, not medical advice. Your care team makes the decisions.

Everyday life

Living with a rare condition is easier with support.

  • Connect with Fetal Health Foundation and other patient organizations
  • Keep notes on symptoms, changes and questions for appointments
  • Ask about patient registries that help research
  • Look into financial aid and travel resources for care visits
Bring these questions to your next doctor visit
How is the pregnancy monitored for TTTS?
Which specialists, such as maternal-fetal medicine, should we see?
What treatment options exist if TTTS is found?

Quick facts

It occurs when blood moves from one twin to the other during pregnancy in identical twins who share a placenta.

Urinary and Reproductive

Also known as: fetal blood loss from fetal hemorrhage into co-twin; fetal hemorrhage into co-twin; fetal transfusion syndrome; feto-fetal transfusion syndrome; fetofetal transfusion; fetofetal transfusion syndrome

Patient organizations

Source: NIH GARD · Twin-to-twin transfusionGARD ID 325 · GARD page updated September 2026 · Plain-language summary by Know Rare; editorial review pending. General information, not medical advice.

You are more than your diagnosis

Perspectives from people navigating life with Twin-to-twin transfusion.

Explore the Twin-to-twin transfusion blog
Broader resource

9 Things to Know After Diagnosis

Read article
Broader resource

The Invisible Job: What Caregiving for a Rare Disease Really Looks Like

Read article
Broader resource

Embrace the Ask: How to Seek The Support You Need

Read article
Your experience could help someone else.

Share your story with our editorial team.

Share your story You choose what to share.

Explore research for Twin-to-twin transfusion

Explore actively recruiting Twin-to-twin transfusion studies with HealthSpark.

HealthSpark

Find actively recruiting studies for Twin-to-twin transfusion with HealthSpark. Share your city to explore research near you.

  • Recruiting studies from ClinicalTrials.gov
  • Share your city to look for research near you
  • Eligibility is confirmed by the study team

Powered by HealthSpark, our AI chat helper

I can help you find recruiting Twin-to-twin transfusion studies. Enter a ZIP code, address or city below and I'll look within 50 miles.

Powered by HealthSpark, our AI chat helper · Study information from ClinicalTrials.gov · Eligibility is confirmed by the study team.

Get Signals for Twin-to-twin transfusion

Stay in the loop with community stories and updates from medical researchers.

HealthStoryfor Twin-to-twin transfusion

Create a living journal that talks back

HealthStory evolves private journaling with a living AI journal that talks back and asks thoughtful questions, helping you capture your Twin-to-twin transfusion experiences more deeply and prepare for better conversations with your doctors and care team.

Start your journal

Your journal is private. Sharing your story publicly is a separate choice, made with Share your story above.