Fetal biometry reference charts for North Indian Population

Fetal biometry is an integral part of obstetric management starting form accurate estimation of the gestational age in the first trimester to assessment as well as monitoring of fetal growth later in pregnancy. It is long recognised that these measurements are specific to different populations and the best charts for a particular ethnicity should be based on ‘nomograms’ established for that population. This study was undertaken to establish reference ranges for fetal biometry for healthy Indian women. This retrospective observation study includes all low risk pregnant women who attended the Fetal Medicine clinic from January 2007 to January 2013 for routine obstetric ultrasounds and went on to deliver a healthy newborn at or after 37 weeks. The number of ultrasound examinations were limited to three per fetus. All women signed an informed consent for the study. Care was taken during data collection to strictly maintain the confidentiality of all participants . The 5th, 10th, 50th, 90th and 95th centiles for each growth parameter (biparietal diameter, head circumference, abdominal circumference and femur length) was calculated for each gestational week from 16 to 40 weeks and plotted to make nomograms.