The role of fetal growth restriction and gestational age on length of hospital stay in twin infants

Objective: To evaluate the association between length of gestation and fetal growth restriction (FGR) and the role of FGR in neonatal morbidity as determined by length of hospital stay among newborn twins. Methods: Using a race-, gender-, and gestational age-specific birth weight and length of hospital stay singleton standard, 490 twin infants were classified as FGR (at or below the tenth percentile) or non-FGR (above the tenth percentile). Length of stay and length-of-stay ratio (twin stay divided by the 50th percentile singleton stay) were calculated for each twin. Analysis included stepwise multiple regression for length of stay and length-of-stay ratio, and analysis of variance with main effects and second-order interactions for the length-of-stay measures using factors significant in the multiple regression models. Results: For length of stay, significant factors in the multiple regression model included respiratory distress syndrome (RDS), gestation category, FGR, sepsis, time of birth (1979–1984 versus 1985–1989), and cesarean delivery. For length-of-stay ratio, significant factors included FGR, gestation category, sepsis, period of birth, cesarean delivery, and hyperbilirubinemia. The analysis of variance showed that RDS had the greatest effect on length of stay, whereas FGR had the greatest effect on length-of-stay ratio. For both dependent variables, the effect of FGR was magnified when compounded by significant neonatal complications (RDS, sepsis, hyperbilirubinemia) or gestation category. Conclusions: Fetal growth restriction is a major factor in the neonatal morbidity of twins. Early recognition of and interventions for FGR in twin gestations should be a primary goal for reducing both immediate and long-term adverse outcomes.