Twin to Twin Transfusion Syndrome (TTTS)
If you're expecting twins or triplets, you'll be monitored to see if any of the babies share a single placenta. This is to screen for Twin to Twin Transfusion Syndrome (TTTS), a life threatening condition where one of your babies receives more blood and nutrients than the other baby does.
EvergreenHealth is a national leader in the evaluation and treatment of TTTS, and is one of only a handful of centers in the United States currently able to provide both nonsurgical and in utero surgical treatments for TTTS.
What is Twin to Twin Transfusion Syndrome?
"Call it mom's intuition…I knew something wasn't right." - Testing picked up signs of Twin-to-Twin Transfusion Syndrome (TTTS). Her babies would need delicate in-utero surgery at EvergreenHealth to survive. Read Natalie's story
Twin to Twin Transfusion Syndrome (TTTS) is a condition that occurs in identical twins or triplets who share a single placenta where one baby donates its blood and nutrients to his/her sibling(s).
This happens in approximately 10-15% of identical twins/triplets who share a placenta.
The baby who is donating his/her blood is at risk of dehydration and anemia. The baby who is receiving the extra blood is at risk for volume overload which can lead to congestive heart failure in severe cases.
TTTS is usually diagnosed by ultrasound between 16 and 26 weeks of pregnancy by a high-risk OB center.
What will happen without treatment?
If not treated, TTTS will continue to worsen and both babies will likely pass away (80-100% of the time).
Babies that survive a pregnancy with severe TTTS and no treatment have a 1 in 4 risk of brain injury due to lack of oxygen, blood and other nutrients. This pregnancy may also be jeopardized by the excessive fluid, which rapidly enlarges the uterus, potentially causing preterm labor and delivery.
What are the treatment options for TTTS?
Serial Amnioreduction
"We are so lucky that Anna and Katie are healthy and happy," says mom Karen Dennis - but it was more than just luck that helped her adorable twins into the world. Read Karen's story
Serial amnioreduction is a less invasive approach in managing the symptoms of less severe cases of TTTS. It involves removing the excess fluid from around the recipient twin with a needle, similar to an amniocentesis.
It reduces the amount of fluid around the recipient twin and temporarily alleviates some associated pain and pressure, but it is not a cure. It will need to be repeated multiple times over the course of your pregnancy.
This technique is often recommended for milder cases of TTTS or cases occurring after 26 weeks of pregnancy, but it is generally not effective for severe TTTS.
Results for Serial Amnioreduction
- At least one twin survives in 40-60% of the cases
- Approximately 25% of surviving twins have some brain damage
Laser Photocoagulation
Laser photocoagulation is an in utero surgical treatment for TTTS. The surgery is done in an operating room using spinal anesthesia, and typically takes 30-to-60 minutes.
The procedure involves placing a very thin camera, called a fetoscope, into the uterus through a tiny 2-3mm incision in the skin. The fetoscope allows our surgeon to identify the small connecting blood vessels on the surface of the placenta. There may be as few as one or two connections, or there may be as many as 19 or 20, depending on the specific case.
Our surgeon then closes the blood vessels using laser energy from a small laser fiber through a channel on the fetoscope.
Results for Laser Photocoagulation
EvergreenHealth's Dr. Martin Walker and Dr. Bettina Paek are among the few physicians in the country trained in laser photocoagulation to treat TTTS. Together they have performed more than 460 laser photocoagulation procedures, with the following results:
11-year-old twins Dakota and Alexia Neal insisted on a summer road trip to meet the surgeon who had saved their lives—before they were even born. Watch Dakota & Alexia's story
- One twin survives in 90% of the cases
- Both twins survive in 60-70% of the cases
- Less than 5% of surviving twins have brain damage
What are the possible risks?
- Chorioamnionitis, rupture of membranes, premature labor and miscarriage
- Maternal complications, such as abruption and infection, occur in less than 1% of cases
- Premature labor occurs in up to 10% of cases
Who is a candidate for laser photocoagulation?
Pregnancies are considered appropriate for laser photocoagulation to treat TTTS when they have the following:
- Single placenta with a thin dividing membrane
- Excess fluid around the recipient twin (greater than 8-to-10 centimeters)
- Low fluid around the donor twin (less than two centimeters)
- Prominent bladder in the recipient and non-filling bladder in the donor
Patients with the following situations may not be suitable for laser photocoagulation in TTTS:
- Pre-term labor with a short or open cervix
- Prior septostomy procedure
- Abnormal genetic studies
- Ruptured membranes
- Infection of the amniotic fluid
Follow-Up Care for Laser Photocoagulation
After the surgery, you can return to the care of your OB for the remainder of your pregnancy and delivery. You and your OB can always contact us if there are any questions or concerns.
Twin-to-Twin Transfusion Syndrome FAQ
How is TTTS diagnosed?
The diagnosis of Twin-to-Twin Transfusion Syndrome (TTTS) is made when the ultrasound reveals one twin (donor) to have an abnormally low level of amniotic fluid while the other twin (recipient) has an excessive amount of amniotic fluid.
Some pregnant women with TTTS notice a sudden change in the fullness or tightness of their belly and/or uterine contractions from the excessive amniotic fluid around the recipient twin.
Is it mild or severe?
TTTS can be mild or severe, depending on how the babies are affected. Each case is unique in presentation as well as in the course of disease progression.
What are the stages of TTTS?
TTTS is divided into different stages, 1 through 5, to determine when to begin medical intervention and what method to use.
Stage 1
Stage I is generally considered the minimum criteria to technically be diagnosed with TTTS. If there are no concerns about pre-term labor, medical intervention is usually not recommended.
However, the pregnancy should be closely monitored by a qualified Maternal-Fetal Medicine specialist due to the unpredictable nature of the disease. TTTS can progress rapidly, stay stable or regress. All pregnancies at risk for TTTS should be monitored at least every two weeks and more frequently if there are any concerns.
Stage 2
Stage 2 results when the bladder in the donor twin is not visible during the course of the ultrasound exam. This indicates that the bladder is empty and signals worsening dehydration of the donor twin. Medical intervention is recommended, as TTTS Stage 2 does not often improve on its own.
Stage 3
Stage 3 is reached when the blood flow patterns (Doppler studies) have become critically abnormal. Blood flow patterns are measured in three areas of each twin: the umbilical cord, the middle cerebral artery (a vessel in the brain) and the ductus venosus (a vessel near the liver). These measurements give the physician a sense of how each baby is tolerating the progression of TTTS.
This stage requires intervention by laser photocoagulation.
Stage 4
Stage 4 is reached when the recipient twin has developed swelling under the skin (hydrops) and appears to be in heart failure. This situation is now critical and requires urgent intervention by laser photocoagulation.
Stage 5
Stage 5 means that one of the twins has died. This can happen to either twin. Thorough ultrasound examination of the survivor is important to ensure that this baby has not been adversely affected. Sometimes an intrauterine fetal blood transfusion may help the survivor.
