To have twin to twin transfusion syndrome, you must have identical twins with a single placenta (monochorionic). This is most reliably seen by ultrasound in early pregnancy (before 16 weeks). After this time, a monochorionic pregnancy is likely if:

  • There is a single placenta.
  • Both babies are the same sex.
  • The dividing membrane is thin all the way to where it meets the placenta
  • There is a significant difference in their sizes
  • There is a significant difference in the amniotic fluid volume in each sac.
  • There is marked difference in bladder filling between babies.
  • You are uncomfortable because your abdomen has suddenly become much bigger.
  • Your uterine contractions are worse since your abdomen has become bigger.

Patients who develop TTTS typically report some or all of these findings. If you are concerned about this possibility, you should contact your obstetrician or perinatologist.

Treating TTTS

Before deciding which approach to use, we must be sure treatment is necessary because every approach has some drawbacks or complications and none is perfect.

Going ahead with intrauterine treatment requires:

  • Lethal fetal abnormalities be excluded
  • Quintero stage 2, 3, or 4
  • Previable gestational age (before 26 weeks)
  • No preterm labor
  • Uncomplicated maternal condition, suitable for surgery
  • Informed consent

You may choose you'd like to manage TTTS instead of treating it. Learn more about managing TTTS.