Fetal growth velocity as a predictor of small for gestational age at birth and adverse perinatal outcomes: systematic review and meta-analysis

OBJECTIVE: This study aimed to evaluate the role of fetal growth velocity in predicting small-for-gestational-age at birth and adverse perinatal outcomes. DATA SOURCES: A systematic review and meta-analysis was conducted through an electronic search of PubMed, Embase, and CINAHL, including studies published between January 2000 and February 2025. STUDY ELIGIBILITY CRITERIA: Both prospective and retrospective studies of pregnancies undergoing longitudinal growth assessment, from the second to the third trimester or within the third trimester, were included. METHODS: This study was registered with PROSPERO (International Prospective Register of Systematic Reviews) (CRD42025642750). Pooled sensitivity and pooled specificity with 95% confidence interval and pooled risk estimates were synthesized using random- and fixed-effects models, respectively. Risk of bias was assessed using the Newcastle-Ottawa scale and the QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies), whereas certainty of evidence was evaluated using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach. RESULTS: The electronic search yielded 5.440 citations. Following full-text review of the potentially eligible studies, 21 studies were included. The predictive and risk stratification value of fetal growth velocity for small-for-gestational-age at birth and adverse perinatal outcomes was assessed across cohorts of 185.441 and 164.341 singleton pregnancies, respectively. Slowing fetal growth velocity showed suboptimal predictive performance for small-for-gestational-age at birth, with pooled sensitivity and specificity for abdominal circumference and estimated fetal weight growth velocity (defined as z-scores divided by interval time in days) of 0.22 (95% CI, 0.09-0.44) and 0.92 (95% CI, 0.92-0.95), and 0.55 (95% CI, 0.53-0.56) and 0.96 (95% CI, 0.96-0.96), respectively (GRADE: low). Slowing fetal growth velocity showed a moderate association with adverse perinatal outcomes: abdominal circumference growth velocity <10th centile was associated with composite adverse perinatal outcome among fetuses predicted to be small-for-gestational-age (pooled odds ratio, 2.47; 95% CI, 1.69-3.82), whereas a fixed centile drop in abdominal circumference/estimated fetal weight ≥50 significantly increased the risk of perinatal death, irrespective of estimated fetal weight (pooled odds ratio, 3.92; 95% CI, 2.03-7.58) (GRADE: moderate). CONCLUSION: Fetal growth velocity might be considered a moderate risk factor for adverse outcomes, but it did not improve prediction over cross-sectional biometry, either at 32 or 36 weeks of gestation, even when implemented in multivariable models. Its clinical utility may lie in complementing third-trimester biometry and maternal/fetal Dopplers in risk stratification. However, standardized definitions and formulas are urgently needed to improve reproducibility and guide implementation in antenatal care.