Comparison Of Clinical Methods And Ultrasound For Prediction Of Expected Fetal Weight With True Birth Weight In Term Pregnancies- A Prospective Study

Abstract

Background- ABSTRACT Fetal weight is an important predictor of perinatal morbidity, mortality and maternal morbidity. Apart from its role in diagnosing IUGR, it guides to choose the mode of delivery to give the best possible outcomes to both mother and child. Fetal weight can be estimated by ultrasound ( USG ) , clinical methods like measurements of symphysio-fundal height ( SFH ) and abdominal girth( AG ) . Ultrasound needs training, expertise and is an expensive equipment which may not be easily available especially in low-resource settings.In such circumstances, clinical methods of estimating fetal weight aid in obstetric decision making. Therefore development and validation of simple, inexpensive, accurate and effective clinical methods are important and relevant especially in countries like India where high cost equipment and trained manpower are scarce. Materials and methods- This is a prospective study of 200 term pregnant women who were admitted to labour ward either in early labour for induction of labour or for elective LSCS. Women fulfilling inclusion criteria were enrolled. Ultrasound examination was performed if she did not possess a report of the scan done in the past one week for expected fetal weight ( EFW ) by mediscan and Hadlock formula. SFH and AG were measured. Estimated fetal weight was calculated using two clinical formulae-Johnson’s and Dare‘s formulae.These were compared with true birth weight ( TBW ) . vii Statistical analysis- Average error, maximum error and percentage error was calculated for all the methods. Co-relation co-efficient was calculated using mean average errors and compared using unpaired “t” test. Results- Between birth weight of 2500 gms and 3500gms clinical formulae predicted EFW as accurately as USG with average error of 250- 300gms and percentage error of 10-15% of TBW. Dare’s formula correlated better than Johnson’s formula with true birth weight . Conclusion- Clinical formulae can be used to predict EFW in routine obstetric practice.USG can be used in clinical suspicion of IUGR or macrosomia.