Joshi, BR2026-04-172026-04-172017https://hdl.handle.net/20.500.14572/5798BR Joshi Department of Radiology and Imaging, Tribhuvan University Teaching Hospital, Kathmandu, NepalAbstract Introduction:The ratio of HC and AC is the best conventional sonographic criterion for detection of intrauterine growth retardation. This study was conducted to determine the relationship of the ratio with GA in Nepalese population. Methods: This prospective longitudinal study was based on 211 low-risk pregnancies. Results: The ratio showed a continuous descending pattern until term. Conclusion: The HC\AC ratio is around 1 and showed a continuous descending pattern until term. Keywords: Abdominal circumference, head circumference, HC\AC ratio, intrauterine growth retardationen-USAbdominal circumferencehead circumferenceHC\AC ratiointrauterine growth retardationArticle