Objective: To estimate the influence of fetal growth restriction (FGR) on neonatal morbidity and mortality among premature discordant twin neonates.
Study design: Our medical records (2002-2007) of preterm twins born at 24-37 weeks' gestation were reviewed. Significant discordance was defined as >15% difference in birth weight. Small for gestational age (SGA) was defined as birth weight <10(th) percentile, and appropriate for gestational age (AGA) was between the 10(th) and 90(th) percentile, according to a twin and sex-adjusted gestational age nomogram. The SGA/AGA group comprised of one SGA twin and its AGA pair (30 pairs). Another group of non-SGA discordant twins was also evaluated (n=40 pairs, AGA/AGA). The morbidity and mortality rates were compared between the groups.
Results: Of the selected outcome variables, the only ones in which the incidence was significantly lower for SGA neonates than their AGA pairs were respiratory distress syndrome (5 vs. 11, P=0.014), apnea (1 vs. 9, P=0.004) and the need for respiratory support (5 vs. 14, P=0.002). Anemia, erythropoietin therapy and hyperbilirubinemia were significantly higher in the SGA twin. All selected outcome variables had similar rates within the AGA/AGA pairs.
Conclusion: FGR among premature discordant twin pairs is associated with significantly lower rates of respiratory morbidity and higher anemia and erythropoietin therapy rates. Overall morbidity is similar for discordant non-FGR twin pairs.