Hypothesis:
Maternal hyperglycaemia is associated with placental stiffness
Objective:
To assess feasibility of two-dimensional ultrasound-guided shear-wave elastography (2D-SWE) measurements for detecting higher placental stiffness scores in women with diabetes mellitus.
Methods:
Consecutive, consenting participants attending a high-risk pregnancy antenatal clinic were recruited. The placenta was identified using grayscale ultrasound-imaging with in-built ElastQ software (for stiffness measurements) utilized to acquire ten measurements/participant in the placental parenchymal bed. Stiffness values in kilopascals (kPa) were recorded. Correlation between HbA1c and placental stiffness was assessed by mixed effects model for repeated measures. A secondary regression analysis was conducted to analyse differences according to subtype of diabetes: type 1 diabetes mellitus (T1DM), type 2 diabetes mellitus (T2DM) and gestational diabetes mellitus (GDM).
Results:
Among 27 participants (T1DM=7, T2DM=5, GDM=7, controls=8), placental stiffness and HbA1c were inversely related (p=0.152). For each 1% (11 mmol/mol) increase in HbA1c, there was a non-statistically significant 0.219kPa (SEM 0.153) decrease in placental stiffness.
Mean placental stiffness score was not statistically significantly different (p=0.19) between groups: T1DM 5.08 (SEM 0.30) kPa, T2DM 5.27 (SEM 0.46) kPa, GDM 5.26 (SEM 0.42) kPa, controls 5.84 (SEM 1.86) kPa.
Placental stiffness measurements showed intra-individual co-efficient of variation ranging 7.9% to 52.3% (latter in the most technically difficult studies due to anatomical positioning of placenta and/or body habitus).
Conclusion:
2D-SWE could not detect statistically significant differences in placental stiffness between women with hyperglycaemia in this study. New and novel markers of placental stiffness or function are needed to identify deleterious effects of hyperglycaemia