Twin-to-Twin Transfusion Syndrome: As an Obstetric Emergency
The incidence of multiple births has increased dramatically due to the increasing application of assisted reproductive techniques and advanced maternal age. Twin-to-twin transfusion syndrome (TTTS) occurs in about 15 % of monochorionic–diamniotic twin pregnancies. The syndrome is caused by unbalanced blood flow through vascular placental anastomoses between the twin fetuses. It presents sonographically as an oligohydramnios–polyhydramnios sequence hence also known as TOPS sequence.
Early diagnosis of a twin pregnancy and establishing the chorionicity by 8–9 weeks helps plan a protocol for individual patient monitoring and follow-up. Timely detection and treatment of TTTS before severe complications such as preterm prelabor rupture of membranes, very preterm delivery (24–32 weeks of pregnancy), fetal hydrops, or single fetal demise occur helps to save many fetal lives.
As the symptoms and staging of TTTS are clearly defined, patient education, accurate and early determination of chorionicity, followed by the first trimester scan and targeted serial fortnightly scans make the syndrome, if present, easy to diagnose. Early diagnosis is the key to effective management. Ultrasound and fetoscopy-guided identification and ablation of the vascular placental anastomoses have revolutionized the management of TTTS ensuring higher perinatal survival rates, more advanced gestational age at delivery, and better neurological outcome in the surviving twins.
KeywordsTwin Pregnancy Nuchal Translucency Ductus Venosus Amniotic Fluid Volume Cord Insertion
- 5.Tchirikov M. Monochorionic twin pregnancy: screening, pathogenesis of complications and management in the era of microinvasive fetal surgery. J Perinat Med. 2010;38:451–9. Copyright by Walter de Gruyter Berlin New York. doi: 10.1515/JPM.2010.069.