Deceleration of fetal growth rate as alternative predictor for childhood outcomes: a birth cohort study

BACKGROUND: Small for gestational age (SGA) is frequently used to define fetal growth restriction (FGR). However, FGR describes a slowdown in fetal growth and is not synonymous with SGA, which may introduce misclassification. We investigated the effect of both on delivery and childhood outcomes. METHODS: From a prospective population-based cohort study we included 7959 live singleton births with data available on second trimester estimated fetal weight (EFW) and birth weight. We used a decrease in growth of > 40 percentiles between second trimester EFW and birthweight to define a deceleration in growth. SGA was defined as birthweight <p5. RESULTS: Deceleration of growth occurred in 27,2% in SGA neonates and in 10,3% of neonates with an appropriate for gestational age (AGA) birthweight. Of all fetuses with decelerated growth, 90% was born AGA. SGA neonates were more often delivered by instrumental delivery or cesarean section and admitted to NICU. Both decelerated growth and SGA were associated with accelerated growth at 2 years, a smaller aortic diameter and lower left ventricular mass at 6 years. CONCLUSIONS: Both decelerated growth and SGA are associated with unfavorable clinical outcomes in childhood. In addition to SGA, neonates with deceleration of growth should be considered a high-risk group. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s12884-019-2358-8) contains supplementary material, which is available to authorized users.