Sonographic Determination of Fetal Size from 20 Weeks of Gestation Onward Correlates with Birth Weight

Objective: To evaluate the clinical efficacy of ultrasonographic measurement of fetal weight, estimated fetal weight (EFW) was analyzed in relation to birth weight. Method: Data were collected retrospectively from the medical records of 548 term pregnancies unassociated with fetal malformations. The subjects underwent sonographic examinations from 20–23 weeks onward at 4 weeks intervals for the estimation of EFW. Subjects were divided into 6 subgroups based on birth weight deviation (BWD) (A: – 3.0 ≤ BWD < – 2.0; B: – 2.0 ≤ BWD < – 1.5; C: – 1.5 ≤ BWD < – 1.0; D: – 1.0 ≤ BWD < – 0.5; E: – 0.5 ≤ BWD < + 0.5 and F: + 0.5 ≤ BWD). Distribution and changes in EFW deviation (EFWD) with gestational age were analyzed related to BWD. Result: A difference in fetal growth based on EFWD was noted in small for gestational age (SGA) cases compared to non-SGA cases, and the difference was observed as early as 20–23 weeks. EFWD was significantly correlated with BWD from 20–23 weeks to term. Conclusion: Sonographic determination of fetal growth from 20 weeks of gestation onward correlated with birth weight deviation, and this emphasized the clinical value of evaluating fetal growth during the latter half of pregnancy.