OP16.01: Comparison of placental blood flow in the second trimester between normal and diabetic pregnancy using 3D power Doppler standardised to a local vessel

Abstract

Objectives: In maternal diabetes the placenta is large with abnormal vascular development and increased villous volume. A prospective, longitudinal observational study of 3D power Doppler vascular indices was performed to investigate differences in-vivo in placental vascularity between women with and without diabetes. Methods: 28 normal women and 20 with pre-gestational diabetes, were recruited. Each subject had 3 scans between 12 and 20 weeks gestation using a Voluson 730 Expert scanner. The VOCAL tool within 4D View (GE Medical Systems) was used to outline the placenta in the A plane using the 9◦ rotation step. To compensate for depth attenuation the 3D vascular indices were standardised against the FI at the centre of a nearby vessel. Results: Subjects were matched for age, BMI and parity. Mean FI.fmbv was 52.07 (±6.0), 50.48 (±5.1) and 53.83 (±4.6) at 12, 16 and 20 weeks respectively. ANOVA demonstrated a significant difference across gestation for the FI.fmbv [F(1.86, 83.82) = 6.37; P = 0.003] and between groups (P = 0.001). There was no difference across gestation or between groups (VI.fmbv, P = 0.29; VFI.fmbv P = 0.48) for the other two standardised 3D vascular indices. The FI.fmbv was significantly higher in subjects with microalbuminuria but not related to retinopathy, hypertension, diabetes type or duration. Conclusions: Standardised placental FI (FI.fmbv) is increased in women with diabetes between 12 and 20 weeks gestation. Structural changes in the large and apparently vascular placenta are therefore accompanied by altered function, with increased signal intensity but not markers of vessel numbers demonstrable in-vivo.