Diameter of the fetal pancreas and abdomen-to-pancreas-ratio: novel ultrasound parameters in fetal growth restriction

PURPOSE: The aim of this study was to compare fetal pancreas size at second trimester ultrasound screening of growth-restricted and normal weight fetuses. METHODS: One hundred sixty-six fetuses between 18 + 0 and 21 + 6 weeks of gestation were included in this retrospective study. 83 fetuses with a birth weight below the 10th centile were included in the study group which was further subdivided into two subgroups depending on the presence (subgroup 1) or absence (subgroup 2) of prenatal signs of fetal growth restriction. The control group consisted of 83 normal fetuses matched for sex and gestational age at examination. The pancreatic diameter (PD) was measured in a standard 2D plane of the fetal abdomen. Statistical analyses comprised descriptive statistics, reliability testing, and multivariable modelling to explore group differences and covariate effects on pancreatic diameter. RESULTS: The diameter of the pancreas was increased in the LBW group compared to the control group [3.7 mm vs. 3.1 mm (p < 0.001)]. The ratio of abdominal circumference (AC) to pancreatic diameter was significantly smaller in the LBW group [41.51 vs. 50.62 (p < 0.001)]. The result was consistent in the subgroup analysis. The difference of the median PD and ratio of AC/PD is greatest in subgroup 1 compared to the control group [PD: 4.2 mm vs. 3.1 mm (p < 0.001) and AC/PD-ratio 35.33 vs. 51.88 (p < 0.001)]. CONCLUSION: The diameter of the fetal pancreas, as measured in this study, is a valuable parameter for the detection of small for gestational age and growth-restricted fetuses. Further studies are needed to further validate our results and their implication for clinical decision-making.