Objective
To determine risk factors for poor cognitive performance among children treated with in utero selective laser photocoagulation of communicating vessels for twin-twin transfusion syndrome (TTTS).
Methods
This was a prospectively enrolled cohort study. Cognitive performance at age 2 years (±6 weeks) was assessed via 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 exam. A priori power analysis determined that a sample of ≥100 children was required for adequate statistical power (0.80).
Results
100 children (57 families) were evaluated. Total BDI-2 score was within normal range (mean=101.3, SD=12.2), with one child having a BDI-2 of <70. Individual child-level risk factors for lower BDI-2 included male sex (β=-0.37, p<0.01), lower head circumference (β=0.28, p<0.01), and higher diastolic blood pressure (β=-0.29, p<0.01). At the pregnancy level, lower maternal education (β=0.60, p<0.001), higher Quintero stage (β=-0.36, p<0.01), and lower GA at birth (β=0.30, p<0.01) were associated with worse cognitive outcomes. Donor/recipient status, GA at surgery, fetal growth restriction, and co-twin fetal demise were not risk factors. The rate of neurodevelopmental impairment (blindness, deafness, cerebral palsy, and/or a BDI-2 score <70) was 4%.
Conclusion
Overall cognitive performance quotients were in the normal range, with risk factors for poor outcomes seen at the pregnancy and child levels. Clinical and socio-economic characteristics can identify at-risk children needing additional interventions.