EP08.48: Comparative assessment of antenatal growth charts in estimating abdominal circumference in Indian population

To assess the difference in abdominal circumference (AC) centiles using three antenatal growth charts (GC) i.e. FMF, MEDISCAN AND HADLOCK GCs and to assess its clinical significance. The study included 797 ultrasounds in 481 patients. The AC centiles used in the dataset were obtained from the converter provided on FMF website, Mediscan from Sonocare software and Hadlock v for their respective GCs. Inclusion criteria were low risk, singleton pregnancies, gestational age between 18 to 40 weeks, availability of a dating scan between 8 to 14 weeks. All the women were of Indian origin. Exclusion criteria were major structural anomalies. The AC at two gestational age (GA) groups 18-32 weeks and 32 to 40 weeks were compared between the three GCs i.e. FMF, MEDISCAN, HADLOCK and its clinical significance in identifying Small for Gestational Age fetus was noted. At GA of 18-32weeks, 7.2% of fetuses had AC < 10 centile according to FMF GC, 2.9% according to MEDISCAN GC and 11.7% according to HADLOCK GC. At GA of 32-40 weeks, 16.5% of fetuses had AC < 10 centile according to FMF GC, 2.7% according to MEDISCAN GC and 23.7% according to HADLOCK GC. The study confirms the variation in AC centiles across the two gestational age groups in the three antenatal GCs. The wide disparity among the GCs in identifying the small for gestational age fetus across both the gestational age groups poses a challenge to the clinician in assessing the fetus to be small for gestational age.