Multiple gestations (twins, triplets and higher order) represent approximately 3.4% of all births in the United States. Compared to singletons, these pregnancies are at a higher risk of preterm delivery and low birth weight. In addition, they may develop specific complications depending on whether the fetuses share a common placenta (monochorionic) or not (dichorionic,
Because some of the complications of twins and triplets are associated with whether the fetuses share a common placenta or not, the diagnosis of the type of twin pregnancy (monochorionic -one shared placenta) (dichorionic – separate placentas, not shared) is essential. In addition, the diagnosis of the number of fetal sacs is also very important, particularly to rule out the presence of two or more fetuses within the same sac.
The diagnosis of
Specific complications in monochorionic twins include a higher rate of birth defects, twin-twin transfusion syndrome (TTTS), selective intrauterine growth restriction (SIUGR) and twin-anemia polycythemia syndrome (TAPS). Monoamniotic twins (2 fetuses in a single sac) can have a higher rate of fetal death and other problems. Complications
Dr. Quintero and Dr. Kontopoulos have an extensive experience in the assessment and management of complicated multiple gestations. As a result, patients are referred from within the United States as well as from abroad to our center to benefit from this experience. Our twin clinic specializes in the assessment,
Monochorionic twins have
Twin-twin transfusion syndrome (TTTS) is a complication of monochorionic twins in which an uneven exchange of blood between the fetuses through placental vascular anastomoses produces oligohydramnios in the donor twin and polyhydramnios in the recipient twin. Untreated, TTTS results in the loss of most pregnancies or in very early preterm birth. Definitive treatment of TTTS is achieved by occluding with laser energy the placental vascular anastomoses responsible for the syndrome.
Selective intrauterine growth restriction (SIUGR) occurs when the estimated fetal weight of one of the fetuses is below the 10th percentile. Management of SIUGR depends on additional complicating factors, such as blood flow studies. Although most pregnancies with SIUGR can be managed expectantly, laser therapy, similar to the one performed for TTTS, may be needed in a small subset of patients.
Twin-anemia-polycythemia syndrome (TAPS) occurs when one of the twins is suspected as being anemic, while the other twin has an excess of red blood cells (polycythemic). The cause of this complication of monochorionic twins is unknown. Management may involve a combination of strategies, including laser therapy similar to the one performed for TTTS, intrauterine transfusion of the anemic twin, or a combination of these.
Monoamniotic twins (2 fetuses within the same sac), aside from being at risk for all of the complications seen in the other types of monochorionic twins, are at risk of becoming entangled with their umbilical cords. The resulting cord entanglement may jeopardize the life of one or both twins. Management of these pregnancies is extremely