Clinical estimation of fetal weight in term pregnancy

Abstract

Objective: The estimation of weight of the fetus by physicians and midwives affects on antepartum and intrapartum cares and the choice of suitable method for the mode of delivery. This study was done to evaluate the value of the clinical examination and estimation of fetal weight by using Johnson formula in term pregnancy. Methods: In this descriptive and analytical study, 230 term pregnant women in their early stages of labor with cephalic presentation referred to Niknafs hospital in Kerman were consecutively chosen. Last menstrual period, parity, the round of arm, fundal height in 4 different positions after voiding, and neonatal weight were registered for each patient. Estimated fetal weight was calculated by Johnson formula. Findings: There was a significant relationship between neonatal weight and the height of uterine funds in different positions, especially in supine position with flexed knees. Correlation coefficient in all positions was more than 0.68. Also, correlation coefficient between estimated and true fetal weight in supine position with flexed knees was 0.50 (P=0.008) and in three other positions was more than 0.48 (P=0.01). Conclusion: Using of clinical examination and Johnson formula are recommended for estimation of fetal weight in all obstetric centers, especially primary centers.

Keywords

• clinical examination
• neonatal weight
• estimated fetal weight
• fundal height
• jhonson formula