Evaluate the impact of third trimester ultrasound in identifying ,small for gestational age (SGA) growth restricted (FGR) and appropriately grown fetuses (AGA).Analyse their outcomes ,ascertain the main causes of perinatal death and lastly compare ultrasound intervention to standard antenatal care . Design Prospective observational study Setting Secondary care, government hospital Population Antenatal women Methods Based on estimated fetal weight by scan , patients were categorized into FGR < 3, SGA >3 and <10 and AGA >10 centile. Perinatal outcomes and deaths were analysed by category. Health Ministry data was extracted for standard care outcomes and compared to study group. Main Outcomes Perinatal deaths and causes,composite neonatal morbidity ,severe adverse outcomes Results Number of births in study and standard care was 1817 and 15,427 respectively. Detection rate by ultrasound for FGR/SGA fetuses was 28.5%.This contained 44.8% (13/29) of all perinatal deaths. Neonatal deaths, composite neonatal morbidity, serious adverse perinatal outcomes were significantly more in FGR compared to AGA. Standard care group had twice as many stillbirths RR 2.32(1.3-4.1)and early neonatal deaths (RR2.5 (1.18-5.34) . Majority of perinatal deaths (17/29; 58.6%) in study group were the direct result of failure to recognize antepartum/ intrapartum risk factors, leading to delayed delivery. In addition (3/12 ; 25%), women reported late after decreased fetal movements and ( 3/12 25%)were post dated. Ill-equipped nursery contributed to neonatal mortality in (10/17 ; 58.8%) cases. Conclusion Perinatal outcomes will not improve by ultrasound identification of small fetuses unless concomitantly, obstetric protocols and patient awareness programmes are not improved.