ABSTRACT

In this study, we investigate the effects of maternal body mass index (BMI), weight gain during pregnancy, delivery stage, amount of amniotic fluid, and amniotic membrane status on the calculation of estimated fetal weight.

Between January 2012 and January 2013, 100 pregnant women who gave birth in our hospital were reviewed. From records, demographic data of patients, maternal BMI (kg/m²), weight gain during pregnancy, delivery stage, amniotic fluid volume and amniotic membrane status, mode of delivery, ultrasound-estimated fetal weight, and the actual birth weight of the newborn have been reviewed.

Birth weight of fetuses estimated by sonography was in the range of 2680–4345 g with an average of 3467.33±417.30 g. The actual birth weight of the newborns was 3468±383.99 g with an average of 2600–4550 g. With ultrasound-estimated fetal weight and the actual birth weight with error range of ±10%, 76% correct prediction rate (n=76) found. When considering maternal parity, stage of labor (latent phase–active phase), sex of the fetus, preconceptional BMI, and maternal weight gain during pregnancy, there is no statistically significant effect (p<0.05) of these factors on the accuracy of the estimated fetal weight. Decreased amniotic fluid and/or rupture of amniotic membranes in pregnant women ultrasoundestimated fetal weight was closer correlation to the actual birth.

The correct prediction of fetal weight is of great importance because of the potential risk estimation for the mother and newborn and in deciding the mode of delivery. Therefore, variables that affect the probability of errors in ultrasonographic measurements should be considered in advance, and if necessary, measures should be planned again.

Keywords: Estimated fetal weight, actual birth weight, maternal BMI, amniotic fluid