An Observational Study On The Accuracy Of Ultrasound-Based Estimated Fetal Weight In Small For Gestational Age Pregnancies At Sms Medical College, Jaipur
Keywords:
Ultrasound, Estimated Fetal Weight, Small for Gestational Age, Appropriate for Gestational Age, Fetal Growth Restriction, AccuracyAbstract
Background: Reliable fetal weight estimation (EFW) is central to managing pregnancies, influencing both antenatal monitoring and delivery choices. Infants classified as Small for Gestational Age (SGA)—those with birth weights at or below the 10th percentile—bear higher risks of neonatal complications. Although ultrasound remains the principal method to determine EFW, its accuracy in SGA versus Appropriate for Gestational Age (AGA) term fetuses requires additional scrutiny.
Methods: Conducted between March 2020 and February 2021 at the Department of Obstetrics and Gynaecology, SMS Medical College, Jaipur, this prospective randomized observational study enrolled 100 term pregnancies: 50 classified as AGA (control group) and 50 as SGA (test group). Ultrasound measurements predicting fetal weight were obtained within seven days before delivery, and neonatal weights were recorded at birth. Absolute and relative errors were used to evaluate the performance of ultrasound EFW in both groups.
Results: Ultrasound estimations generally overshot actual birth weight. However, underestimation was more apparent in the SGA group, whereas overestimation was frequently noted in the AGA group. The AGA group showed a greater mean absolute and relative error, but these discrepancies stayed within clinically permissible ranges and did not substantially affect management pathways.
Conclusion: Ultrasound-based fetal weight assessment displays comparable accuracy for both SGA and AGA fetuses at term, although clinicians should remain mindful of slight overestimations in AGA cases. Recognizing these subtle variations can help tailor obstetric decisions, especially when addressing suspected intrauterine growth restriction.
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