Developmental outcome of discordant premature twins at 3 years.

Background: There are numerous known or unknown maternal, fetal and intrauterine conditions that may lead to growth restriction. In addition to prematurity and growth restriction, developmental outcome may also be influenced by many genetic and environmental factors.

Aim: To examine the impact of intrauterine growth restriction on development in premature discordant twins.

Study Design: Intra-pair control comparison.

Methods: Developmental outcome at age 3 years was examined in 21 pairs of discordant (>15% birth weight discordance) very low birth weight (VLBW) premature twins.

Results: None of the smaller twins had cerebral palsy and one larger twin had a mild diplegia. In paired comparisons, the smaller twins were somatically smaller and had a slight lower Griffiths' developmental quotient (GQ) than the co-twins without cerebral palsy [mean+/-S.D. 100+/-13, range 73-117, versus 104+/-12, 80-124, p=0.002]. The largest difference was in the locomotor subscale. There was a greater intra-pair GQ difference in the 12 twin pairs who had a discordance of greater than 30% (mean GQ=98 versus 105, p<0.001). The intra-pair GQ correlated well (r=0.90), a finding similar to that of a comparative group of 26 nondiscordant VLBW twin pairs (r=0.87). A multivariate analysis confirmed that gestation and percentage discordance were the important factors influencing GQ.

Conclusion: There exists a strong influence of common intrauterine, genetic and environmental factors on developmental outcome. Despite an overall lack of adverse outcome in smaller twins, results indicated a small but significant influence of growth restriction.