Table 5. Fetal venous liver flow according to pre-pregnancy BMI categories in the reference and pregestational diabetes mellitus populations (160 and 49 participants, respectively).
| Flow z-score | |||||||
|---|---|---|---|---|---|---|---|
| BMI category | Reference population | Pregestational diabetes population | |||||
| n | mean | CI | n | mean | CI | ||
| Umbilical flow | normal | 363 | 0.016 | -0.09–0.12 | 91 | 0.228 | -0.09–0.55 |
| overweight | 155 | -0.121 | -0.28–0.04 | 58 | 0.703 | 0.30–1.11 | |
| obese | 30 | 0.327 | -0.04–0.69 | 43 | 0.206 | -0.26–0.67 | |
| p | 0.130 | 0.144 | |||||
| Umbilical flow to liver | normal | 353 | 0.028 | -0.08–0.13 | 59 | 0.101 | -0.31–0.52 |
| overweight | 150 | -0.143 | -0.30–0.02 | 40 | 0.906 | 0.40–1.41 | |
| obese | 26 | 0.218 | -0.17–0.61 | 24 | 0.063 | -0.59–0.71 | |
| p | 0.190 | 0.033* | |||||
| Ductus venosus flow | normal | 344 | 0.132 | -0.26–0.52 | 70 | -0.145 | -0.59–0.30 |
| overweight | 147 | 0.092 | -0.01–0.20 | 42 | -0.234 | -0.81–0.34 | |
| obese | 27 | -0.171 | -0.33 - -0.01 | 26 | -0.870 | -1.60 - -0.14 | |
| p | 0.005* | 0.237 | |||||
| Ductus venosus flow fraction | normal | 340 | -0.072 | -0.52–0.28 | 59 | -0.158 | -0.56–0.24 |
| overweight | 143 | 0.207 | -0.18–0.04 | 40 | -0.759 | -1.25 - -0.27 | |
| obese | 26 | 0.088 | -0.30–0.48 | 24 | -0.550 | -1.18–0.08 | |
| p | 0.042* | 0.160 | |||||
| Left portal vein flow velocity | normal | 349 | -0.178 | -0.57–0.21 | 100 | 0.591 | 0.35–0.84 |
| overweight | 149 | 0.002 | -0.10–0.11 | 54 | 0.844 | 0.51–1.18 | |
| obese | 30 | 0.037 | -0.12–0.20 | 48 | 0.507 | 0.15–0.86 | |
| p | 0.801 | 0.343 | |||||
| Portal vein flow | normal | 354 | -0.014 | -0.12–0.09 | 51 | 0.315 | -0.25–0.88 |
| overweight | 149 | 0.062 | -0.10–0.22 | 30 | .0385 | -0.35–1.12 | |
| obese | 30 | 0.195 | -0.17–0.56 | 13 | -0.157 | -1.27–0.96 | |
| p | 0.660 | 0.706 | |||||
| Portal vein fraction | normal | 332 | -0.043 | -0.15–0.07 | 42 | 0.066 | -0.80–0.61 |
| overweight | 140 | 0.163 | -0.01–0.33 | 25 | -0.446 | -1.15–0.26 | |
| obese | 26 | -0.090 | -0.48–0.30 | 9 | 0.102 | -1.08–1.28 | |
| p | 0.159 | 0.491 | |||||
| Total venous flow to liver | normal | 333 | 0.012 | -0.10–0.12 | 42 | 0.304 | -0.18–0.78 |
| overweight | 142 | -0.115 | -0.28–0.05 | 25 | 1.087 | 0.47–1.71 | |
| obese | 26 | 0.238 | -0.15–0.63 | 9 | -0.160 | -1.19–0.88 | |
| P | 0.213 | 0.061 | |||||
n, total number of observations in reference (n = 160) and study population (49)
* p-value <0.05, Fetal flow z-score according to body mass index (BMI) categories within each population tested by ANOVA; n, number of observations; Flow (mL/min); Flow velocity, time-averaged maximum velocity (cm/sec); BMI categorized as: normal (18.5–24.9), overweight (25–29.9) or obese (≥30) (underweight BMI category was excluded).
UV flow to liver = UV flow- DV flow.
Total venous flow to liver = UV flow to liver + PV flow.
Ductus venosus flow fraction = DV flow/UV flow*100.
Portal vein fraction = PV flow/ Total venous liver flow*100.