The small-for-gestational-age twin - Blessing or curse?

OBJECTIVE: To compare small-for-gestational-age (SGA) twins to appropriate-for-gestational-age (AGA) twins regarding preterm delivery (PTD). STUDY DESIGN: Retrospective review of maternal and neonatal records of live, nonanomalous twins >= 25 weeks' gestation delivered in 1984-2000 in a tertiary care center. Pregnancies (N=679) were divided into AGA/ AGA (n=347), SGA-AGA (n=191) and SGA/SGA (n=141) groups using singleton growth curves. The PTD rate was compared and logistic regression analysis was done to study factors that influenced PTD at <= 34 weeks. p < 0.05 Was considered significant. RESULTS: The PTD rate at <= 34 weeks was AGA/AGA (38.6%), SGA-AGA (14.7%) and SGA/SGA (1.4%) (p < 0.001). On multiple logistic regression analysis, discordance significantly increased PTD (OR=5.05, 2.47-10.31, p=0.001), while smallness for gestational age significantly decreased PTD (OR=0.095, 0.05-0.17, p < 0.001). The PTD rate increased directly with the increase in the relative overall weight of the twins. CONCLUSION: The PTD rate is higher in AGA twins as compared to SGA twins. The PTD rate is directly related to the overall weight of the twins.