Twin to twin transfusion syndrome

Abstract

Twin to twin transfusion syndrome (TTTS) is a common complication that typically presents in the second trimester of pregnancy in 10-15% of monochorionic twins due to net transfer of volume and hormonal substances from one twin to the other across vascular anastomoses on the placenta. Without recognition and treatment, TTTS is the greatest contributor to fetal loss prior to viability in 90-100% of advanced cases. Ultrasound diagnosis of monochorionicity is most reliable in the first trimester and sets the monitoring strategy for this type of twins. The diagnosis of TTTS is made by ultrasound with the findings of polyhydramnios due to volume overload and polyuria in one twin and oligohydramnios due to oliguria of the co-twin. Assessment of bladder filling as well as arterial and venous Doppler patterns are required for staging disease severity. Assessment of fetal cardiac function also provides additional insight into the fetal cardiovascular impacts of the disease as well as help identify fetuses that may require postnatal follow up. Fetoscopic laser ablation of the communicating vascular anastomoses between the twins is the standard treatment for TTTS. It aims to cure the condition by interrupting the link between their circulations and making them independent of one another. Contemporary outcome data after laser surgery suggests survival for both fetuses can be anticipated in up to 65% of cases and survival of a single fetus in up to 88% of cases.However, preterm birth remains a significant contributor to postnatal morbidity and mortality. Long term outcomes of TTTS survivors indicate that up to 11% of children may show signs of neurologic impairment.Strategies to minimize preterm birth after treatment and standardized reporting by laser centers are important considerations to improve overall outcomes and understand the long-term impacts of TTTS.

Outcome of monochorionic triamniotic triplet pregnancies: Expectant management versus fetal reduction

“…This study showed the incidence of TTTS was 5.3% (1/19) in EM group and 0% in FR group. This seems somewhat lower than the 8%–17.6% and 10%–15% that was previously reported in MCTA triplets and MCDA twins respectively, 11,18,19 which need further large sample and collaborative evaluation in the future. A recent systematic review about the perinatal outcome after fetoscopic laser surgery for TTTS in 22 MCTA triplets revealed that all three fetuses survived in 48.4% of the pregnancies and at least one triplet survived in 88.9% pregnancies, indicating that this technique is feasible for treatment of this condition 20 .…”

Controlled amnioreduction for twin-to-twin transfusion syndrome

“…Accordingly, any intervention that leads to at least one alive twin is considered as a clinical success. 1 , 2 Review of the published outcome of managed TTTS pregnancies revealed an overall success of live twins in the range of 53–78% 5 – 9 post-AR 29 , 36 , 42 , 43 and 50–88% post-FLA. 8 – 10 , 13 This study with the controlled AR protocol demonstrated an impressive overall success with 86% survival of the twins beyond 6 months of age. The best way for classification and management of twin pregnancies is currently still debated with significant global variations.…”

“…Twin-to-twin transfusion syndrome (TTTS) is a complication in monochorionic diamniotic (MCDA) twins in which blood is transferred from a donor to a recipient twin via anastomoses in the shared placenta. 1 The TTTS occurs only in 10–15% of MCDA pregnancies; however, if untreated, the expected perinatal morbidity and mortality is extremely high. 2 Historically, the placenta anastomoses have been well described since the mid-19th century, but intervention procedures were reported only in the late 1970’s.…”

“…2 , 4 Since the early 2000’s, the fetoscopic laser ablation (FLA) of the superficial placental anastomoses became the recommended management for TTTS. 1 – 4 …”

“…In the absence of an objective measures, the decision to terminate the procedure is usually based on the clinical experience of the physician and ultrasound imaging. 1 , 2 , 29 …”