Developmental outcomes in small-for-gestational age twins using a singleton vs twin birthweight reference

Area of Science:

• Neonatal development
• Pediatric health outcomes
• Birth cohort studies

Background:

• Limited data exist on developmental delays in appropriately grown twins.
• Twins may have a higher risk of developmental delay compared to singletons.
• Small-for-gestational age (SGA) classification using singleton references may misclassify appropriately grown twins.

Purpose of the Study:

• To assess the risk of developmental delay in twins identified as small-for-gestational age (SGA) using both twin and singleton birthweight references.
• To compare the utility of twin versus singleton references in identifying developmental risks in twins.

Main Methods:

• A birth cohort of 1790 twins and 3829 singletons (2008-2010) was analyzed.
• Parents completed Ages & Stages Questionnaires (ASQ) for child development between 4 and 36 months.
• Adjusted generalized linear mixed-effects models assessed ASQ failure rates, accounting for twin clustering.

Main Results:

• Uncertain SGA twins (SGA by singleton, not twin reference) did not show increased ASQ failure compared to non-SGA twins.
• Both twin-reference SGA and uncertain SGA twins had higher odds of ASQ failure compared to non-SGA singletons.
• Twin-reference SGA twins exhibited the highest risk (aOR 3.14), followed by uncertain SGA twins (aOR 2.35).

Conclusions:

• A singleton birthweight reference may overestimate SGA in twins but appropriately identifies more twins at risk for developmental delay.
• Findings suggest singleton references are suitable for identifying developmental risks in twins, despite potential overestimation of SGA.
• This approach enhances the identification of at-risk twins compared to twin-specific references.