Fetal weight estimation: importance, challenges and emerging trends

ABSTRACT

Accurate fetal weight estimation is important in preventing and managing fetal and maternal complications. Many fetal weight formulae have been derived, but none seems to be accurate enough to be applied globally for all ranges of fetal weight. Major factors causing errors in fetal weight estimation include inappropriately derived equations not considering ethnic differences among populations, fetal gender difference and different ranges of fetal weight. Use of fetal thigh volume and arm volume for fetal weight estimation by 3D ultrasound may increase the precision of fetal weight formulae. However, the superiority of 3D ultrasound in fetal weight estimation over 2D ultrasound is debatable as greater expertise is required, time consumed is more and there is no substantial increase in accuracy. It is suggested that fetal gender specific, fetal weight range specific and community based formula should be derived and used for better accuracy. Further studies are recommended. Articles published between October 1993 to October 2015 were selected from PubMed and Google Scholar, for this review article