Sequential vs. Standard Laser Treatment of Twin-twin Transfusion Syndrome

Inclusion Criteria:

- Gestational age: 16 weeks, 0 days to 26 weeks, 0 days.

- Confirmed TTTS patients, who by definition meet the following sonographic criteria:

- Single placenta.

- Polyhydramnios: maximum vertical pocket ≥ 8 cm in the recipient twin, prior to
amniodrainage.

- Oligohydramnios: maximum vertical pocket ≤ 2 cm in the donor twin, prior to
amniodrainage.

- Thin dividing membrane (absence of twin peak sign) or absence of dividing
membrane (monoamniotic).

- Same gender, if visible.

- Quintero Stages 1-4.

- Patients choosing laser therapy that have undergone prior therapeutic amniocentesis
may be included.

- Patients with an anterior placenta may be included.

- Triplet gestations with two or three fetuses sharing the same placenta may be
included.

- Patients must be able to give written informed consent.

Exclusion Criteria:

- Patients unable or unwilling to participate in the study or to be followed up.

- Patients unable to give written informed consent.

- Presence of major congenital anomalies that may not warrant surgery.

- Known unbalanced chromosomal complement.

- Prior intentional septostomy (purposely making a hole in the dividing membrane).

- Ruptured membranes.

- Chorioamnionitis.

- Abnormal intracranial ultrasound findings of either fetus to include, but not limited
to: intraventricular hemorrhage, porencephalic cysts, hydrocephalus, Dandy-Walker
syndrome, holoprosencephaly and agenesis of the corpus callosum. Isolated
ventriculomegaly (atrium 10-19 mm) may or may not be used as exclusion criteria.

- Placental abruption.

- Active labor.

- Patient unwilling to receive blood products.

- Recipient twin with a middle cerebral artery peak systolic velocity > 1.5 multiples of
the median (indicative of fetal anemia).

- Any other patient deemed inappropriate for the study by the principal investigator.