*SPECIAL GUEST* - Dr. Michael Bebbington.

This week Dr. Bebbington joins us to talk about the background of twin-twin transfusion syndrome (TTTS) as he covers the following topics:

• Pathophysiology of twin-twin transfusion syndrome (TTTS) ‘Donor’ twin vs. ‘Recipient’ twin
  • Types of vessel anastomoses involved in TTTS
    • AA – artery to artery
    • VV – vein to vein
    • AV – artery to vein
    • VA – vein to artery
  • Pathophysiology of the polyhydramnios and oligohydramnios seen in TTTS
• Assessing Dopplers in-utero using ultrasound and the different fetal vessels Doppler is used on
• Defining the Quintero stages of TTTS (I through V)
  • Stage I – “Poly” & “Oli”
    • Donor DVP <2.0 cm
    • Recipient MVP >8.0 cm
  • Stage II – No visible bladder in donor twin
  • Stage III – Doppler abnormalities in one or both twins (Stage IIID, IIIR, IIIDR, and ‘Atypical Stage III)
    • Absent/reversed end diastolic flow in umbilical artery (UA)
    • Absent/reversed ‘a’ wave in ductus venosus (DV)
    • Umbilical vein (UV) pulsations
  • Stage IV – Hydrops in one or both twins
  • Stage V – Demise of one or both twins
• Risk of demise of both fetuses and physiological changes in the surviving twin should one twin die in-utero
• Atypical presentations of TTTS
• Why we use maximum vertical pocket (MVP) or deepest vertical pocket (DVP) to quantify fluid in twins over an amniotic fluid index (AFI)
• Adjuvant TTTS staging systems
• Frequency and rate of occurrence of TTTS in monochorionic pregnancies
• Prognosis, survival and outcomes of TTTS with and without treatment
• Frequency of surveillance for TTTS in monochorionic pregnancies
• How a laser surgery is performed for treatment of TTTS
  • Solomon technique  
• Recurrent TTTS and TAPS are complications of incomplete laser surgeries
• Amnioreduction at the end of the procedure to remove extra fluid from the recipient twin amniotic sac
• Pre-operative counseling for the patient and common complications that can occur during or after a laser procedure
• Gestational age at which a laser ablation of placental anastomoses typically occurs
• Follow-up after a laser surgery
• Factors associated with poorer prognosis or poorer survival rates
• Average gestational age of delivery after a laser surgery
• Training programs for learning to do laser surgery for TTTS
• The role of selective reduction in TTTS
• Implications laser surgery can have on future pregnancies for patients
• Risk of developing TTTS in a subsequent pregnancy