Clinical phenotypes for risk stratification in small‐for‐gestational‐age fetuses

Objective This study evaluates whether clinical phenotypes of small for gestational (SGA) fetuses can be identified and used for adverse perinatal outcome risk stratification to facilitate decision-making. Methods This multicentre observational cohort study was conducted in two tertiary care university hospitals. It included 17,631 consecutive singleton pregnancies, among which 1274 (7.2%) were defined as SGA at birth according to INTERGROWTH-21st standards. The main outcome was the development of clinical clusters of SGA phenotypes. Results Nine SGA clinical phenotypes were identified using a predefined conceptual framework. Every delivery and perinatal outcome analysed showed statistically significant differences between phenotypes. The total SGA cohort had a 3 times increased risk of perinatal mortality than non-SGA fetuses (1.4% vs 0.4%; pConclusions We identified nine SGA clinical phenotypes associated with different patterns of risk for adverse perinatal outcomes. Our results suggest that adding clinical characteristics to ultrasound results would improve risk stratification and decision-making for SGA fetuses. Future clinical trials on the control of fetuses with SGA should take into account, in addition to Doppler and estimated fetal weight, this clinical information.