Twin-to-Twin Transfusion Syndrome Treatment & Management

Updated: Apr 02, 2020
  • Author: Lisa E Moore, MD, MS, FACOG, RDMS; Chief Editor: Ronald M Ramus, MD  more...
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Approach Considerations

Fetoscopic laser photocoagulation

Fetoscopic laser photocoagulation (FLP) of anastomotic vessels is considered the gold standard of treatment for twin-twin transfusion syndrome (TTTS). First described in 1990, this procedure is performed in specialized centers across the United States and in Europe.   

Abnormal vessels are mapped by following them from origin to termination. A vessel that originates with one fetus, inserts into a cotyledon, and then travels to the other fetus is considered pathologic and is photocoagulated. Vessels that exit the cord as an artery, enter a cotyledon, and return to the same fetus as a vein are not pathologic and are not treated. This procedure is called selective photocoagulation. [22]

An additional modification of the procedure is sequential selective photocoagulation, in which pathologic vessels are ablated in the following order of the type of connections:

  • Donor artery–recipient vein
  • Recipient artery–donor vein
  • Artery-artery
  • Vein-vein

Theoretically, the sequential selective technique reduces hypotension in the donor twin. [23, 24]

The Solomon technique creates a dichorionic placenta by photocoagulating the surface of the placenta from one edge to the other edge in a straight line. (See the image below.) This procedure is done after selective photocoagulation and has been shown to decrease the rate of recurrent TTTS. [10]


A monochorionic placenta with the vasculature of t A monochorionic placenta with the vasculature of twin A in blue/red and that of twin B in green/yellow. This placenta is shown after laser ablation of shared vessels. Close examination reveals the line of photocoagulation using the Solomon technique. Courtesy of Anthony Johnson, DO.


Referral to a specialized center for laser treatment is recommended once the diagnosis is made. Patients between 16 and 26 weeks' gestation are considered candidates for the procedure, although several studies report successful outcomes at later gestations.

Fetal complications of FLP

Fetal complications of FLP include the following [15, 10, 5] :

  • Preterm  premature rupture of membranes (10%); 3-6% within 7 days and 7-9% within 28 days; as high as 30% in some studies.
  • Persistent TTTS (7% reduced to 1% using the Solomon technique).
  • Twin anemia polycythemia sequence (16% reduced to 3% using the Solomon technique).
  • Preterm delivery (50% prior to 34 weeks).
  • Demise of one twin (13-33%).
  • Demise of both twins (22%); studies report survival of at least one twin in 75-88% of cases.
  • Severe long-term neurologic impairment (3-18%).

Maternal complications of FLP

Maternal complications of FLP include the following [25] :

  • Placental abruption: Separation of the placenta from the uterine wall.
  • Amniotic fluid embolism: A serious complication that occurs when fetal cells and other material enter the maternal circulation and cause a severe anaphylactic reaction.
  • Mirror syndrome: A rare life-threatening condition in which the mother develops hypertension and edema that "mirrors" edema in the placenta or the fetus.

Other complications include chorioamnionitis, abdominal pain, and development of pulmonary edema. [10]

Serial amnioreduction

The goal of serial amnioreduction is to reduce hydrostatic pressure on the smaller twin. An ultrasound-guided amniocentesis is performed on the sac of the recipient twin, and as much fluid as possible is removed. Before the use of laser photocoagulation, this procedure was the treatment of choice for TTTS.

The Eurofetus trial enrolled women from 6 countries in a randomized comparison of serial amnioreduction versus laser surgery. [16] The study was discontinued early because a planned interim analysis showed significant benefit in the laser group. 

There may still be a role for serial amnioreduction, particularly in late gestation, to alleviate maternal discomfort, or in cases after 26 weeks, when elective delivery may be considered safer than laser surgery on the placenta.


Septostomy is the deliberate creation of a hole in the dividing membrane. This allows equilibration of hydrostatic pressure and relieves the compression on the placenta of the donor twin.  Effectively, a monoamniotic pregnancy is iatrogenically created. A limitation of the procedure is that it does not address the underlying problem of the unbalanced transfer of fluid volume. Cord entanglement is the major complication. Septostomy is no longer recommended as a treatment for TTTS. [1]

Selective cord occlusion

In monochorionic twins, when one twin dies, the remaining twin may exsanguinate to the dead twin. In cases of TTTS in which the death of one twin is considered imminent and unavoidable, cord occlusion interrupts blood flow to the distressed twin and laser ablation of anastomoses prevents exsanguination of the survivor.

A meta-analysis showed survival was improved in the remaining twin if cord occlusion was performed after 18 weeks. The survival rate among the remaining twins was 79%. No significant difference was found between the death of the donor and the death of the recipient. [26]

Expectant management

Controversy exists regarding the treatment of stage 1 TTTS. Many cases identified at stage 1 either do not progress or regress.  Treatment by laser photocoagulation is recommended for stage 2 TTTS or higher. Consideration can be given to expectant management in stage 1.




A specialist in maternal-fetal medicine should confirm the diagnosis of monochorionic twinning and initiate follow-up every 2 weeks for TTTS screening. The perinatologist will typically make referrals to an interventionist if needed.

Fetal interventionist

If TTTS is diagnosed, referral should be made to a center for fetal intervention for laser photocoagulation.


Referral to a neonatologist is recommended for neonatal care after delivery.



Recommendations for multiple gestations are extrapolated from singleton gestations. With a twin gestation, it is estimated that 40% more calories are needed than in a singleton gestation, which would mean an additional 476-632 Kcal/day in the second and third trimesters. One recommendation for macronutrients is 20% protein, 40% carbohydrates, and 40% fat. [27]

Twins have a 2- to 4-fold increase in iron deficiency anemia and an 8-fold increase in folate deficiency. Micronutrient recommendations include iron and folate supplementation.



Physical activity during pregnancy is encouraged. Regular physical activity helps control weight gain, is beneficial in managing diabetes, and has been shown to enhance well-being during pregnancy.

Multiple gestations and twins affected by TTTS have not been specifically studied; however, it is known that a twin gestation is associated with anatomic and physiologic changes that should be considered when choosing an exercise regimen. 

During pregnancy, a shift in the center of gravity due to the pregnant abdomen and increased pressure on the spine and joints result in low back pain. The ability to tolerate aerobic exercise is impaired because of a decrease in pulmonary reserve and the increased work load of the weight of the pregnancy. [28]

A multiple gestation at risk for premature labor is an absolute contraindication to aerobic exercise during pregnancy.

Intrauterine growth restriction is a relative contraindication to aerobic exercise, indicating that the decision to exercise should be weighed on a case-by-case basis.