Abstract

OBJECTIVE: There is limited data for counseling and management of periviable small for gestational age fetuses. We aim to investigate short term outcome in periviable SGA fetuses and relate this to the underlying cause. METHODS: Retrospective database study conduced in three London tertiary fetal medicine centres between 2000 and 2015. We included viable singleton pregnancies with abdominal circumference ≤ 3rd percentile between 22 + 0 and 25 + 6 weeks. Data obtained included biometry and placental anomalies, uterine and fetal Doppler and neonatal outcome. We excluded those cases with demonstrated structural abnormalities, proven or suspected abnormal karyotype or genetic syndromes. Cases were categorised as uteroplacental insufficiency, evidence of placental damage with normal uterine artery Doppler, viral infection or unclassifiable. RESULTS: 245 cases were included. At diagnosis 201/245 (82%) were categorised as uteroplacental; 13/245 (5.3%) as suspected placental and 30 could not be assigned to any of these categories. Overall, 101/245 (41%) survived; the rate of in utero fetal demise was 89/245 (36%), 22/245 (9%) were neonatal deaths and 33/245 (14%) of pregnancies were terminated. The diagnosis to delivery interval was 8.1 weeks in those that survived, 2.7 weeks in those that died in utero and 3.9 weeks in those that died neonatally. CONCLUSIONS: Over 90% of periviable SGA cases are associated with uteroplacental insufficiency or intraplacental damage. Survival is related to gestation at delivery, with outcomes better than might be assumed at diagnosis and some pregnancies reaching term.