Early Findings of a Preterm Twin Cohort Study Examining the Effect of General Anesthesia on Developmental Outcomes.

Purpose: The premature infant brain may be particularly vulnerable to anesthesia effects, but there is conflicting evidence on the association between anesthesia exposure and developmental outcomes. Twin studies can control for confounding factors. A twin cohort of premature twins provides internal control of difficulty to measure confounders and delivers added power to a study examining the effects of anesthesia on neurodevelopmental outcomes.

Methods: We conducted a retrospective cohort study of sets of premature twins and multiples born at an academic medical center, in which 1 member of the set was exposed to general anesthesia. The primary outcome was the composite scores using Bayley Scale of Infant and Toddler Development III performed at age 6 months to 18 months. Unpaired and paired analyses were performed with linear regression models, Wilcoxon signed rank test, and Mann-Whitney U test.

Results: We identified 81 children born at less than 32 weeks gestation within 39 sets of twins and 1 set of triplets for a total of 18 paired observations. All of the exposed infants had a single exposure to general anesthesia. There was no significant association between anesthesia exposure and a diagnosis of developmental delay (OR = 0.8; 95% confidence interval, 0.2-3.2; p = 0.99). Regression models demonstrated no association between anesthesia exposure and cognitive (96.67 vs 97.50; p = 0.74), language (98.33 vs 98.61; p = 0.94), or motor (96.25 vs 96.44; p = 0.91) composite Bayley scores. There was no association between duration of anesthesia and the 3 composite Bayley scores ( p = 0.33; p = 0.40; p = 0.74).

Conclusion: Using a premature twin cohort with discordant exposure to anesthesia, our data did not demonstrate any association between anesthesia exposure and developmental delay in this vulnerable population of premature infants.