Pregnancy outcome after false diagnosis of fetal growth restriction

OBJECTIVES: To evaluate pregnancy outcome following false diagnosis of fetal growth restriction (FGR). METHODS: Retrospective analysis of all singleton term deliveries of appropriately grown fetuses (10-90th weight percentiles) in a single medical center (2007-2014). Elective cesarean-section, diabetes, and hypertension were excluded. Cohort was stratified based on third trimester sonographic estimated-fetal-weight (≥32 weeks). Women with false diagnosis FGR (<10th percentile) were compared with the rest (control). Induction of labor, cesarean deliveries, and short-term perinatal outcome were compared. Logistic regression analysis was performed to adjust outcome for birth weight and gestational age at delivery. RESULTS: Of 34,474 pregnancies, 415 were falsely diagnosed as FGR (1.2%). Women in study group delivered earlier (38.6 ± 1.1 versus. 39.0 ± 0.9) with lower birth weights (2856 ± 270 versus 3271 ± 307 grams) and increased rate of labor inductions (19.8% versus 6.4%) and cesarean deliveries (10.8% versus 5.7%). Despite appropriate birth weight, study group neonates had higher rates of NICU admissions (10.6% versus 6.8%), mechanical ventilation (1.7% versus 0.5%), transient tachypnea of the newborn (1.7% versus 0.5%), hypoglycemia (1.7% versus 0.5%), and jaundice (11.3% versus 7.0%). p < 0.01 for all. All remained significant after adjustment to confounders. CONCLUSIONS: False diagnosis of FGR is associated with higher rates of induction of labor, cesarean deliveries, and short-term adverse neonatal outcome.