Predictors of 2-year cognitive performance after laser surgery for twin-twin transfusion syndrome

The purpose of this study was to determine risk factors for poor cognitive performance among children who are treated with in utero selective laser photocoagulation of communicating vessels for twin-twin transfusion syndrome.

This was a prospectively enrolled cohort study. Cognitive performance at age 2 years (±6 weeks) was assessed with the Battelle Developmental Inventory 2nd Edition (BDI-2). Multilevel regression models evaluated risk factors for poor cognitive performance at shared (pregnancy) and individual (child) levels. In addition to development, blindness, deafness, and cerebral palsy were assessed based on physical examination. A priori power analysis determined that a sample of ≥100 children was required for adequate statistical power (0.80).

One hundred children (57 families) were evaluated. Total BDI-2 score was within normal range (mean, 101.3 ± [SD]12.2); 1 child had a BDI-2 score of <70. Individual child-level risk factors for lower BDI-2 included male sex (β = -0.37; P < .01), lower head circumference (β = 0.28; P < .01), and higher diastolic blood pressure (β = -0.29; P < .01). At the pregnancy level, lower maternal education (β = 0.60; P < .001), higher Quintero stage (β = -0.36; P < .01), and lower gestational age at birth (β = 0.30; P < .01) were associated with worse cognitive outcomes. Donor/recipient status, gestational age at surgery, fetal growth restriction, and co-twin fetal death were not risk factors. The rate of neurodevelopmental impairment (blindness, deafness, cerebral palsy, and/or a BDI-2 score <70) was 4%.

Overall cognitive performance quotients were in the normal range, with risk factors for poor outcomes seen at the pregnancy and child levels. Clinical and socioeconomic characteristics can identify at-risk children who need additional interventions.