Objective: To compare the changes of placental three-dimensional power Doppler indices and volume in the first and the second trimesters of pregnancy with gestational diabetes mellitus (GDM). Methods: This was a prospective case-control study of singleton pregnancies with risk factors for GDM. Data on placental vascular indices including vascularization index (VI), flow index (FI), and vascularization flow index (VFI), as well as placental volume were obtained and analyzed during the first and the second trimesters between pregnant women with and without GDM. Results: Of the 155 pregnant women enrolled, 31 developed GDM and 124 did not. VI and VFI were significantly lower in the GDM group during the first and second trimesters (VI: p = .023, and VFI: p = .014 in the first trimester; VI: p = .049, and VFI: p = .031 in the second trimester). However, the placental volume was similar in both the groups during the first trimester, while it was significantly increased in the GDM group during the second trimester (p = .022). There were no significant differences in FI and uterine artery pulsatility index between the two groups. After adjustments in multivariate logistic regression analysis, significant differences were observed in the first trimester VFI (adjusted odds ratio (OR) 0.76, 95% confidence interval (CI) 0.61-0.93), second trimester VFI (adjusted or 0.83, 95%CI 0.71-0.96), and second trimester placental volume (adjusted or 1.03, 95%CI 1.01-1.05). Conclusions: Placental vascular indices can provide an insight into placental vascularization in GDM during early pregnancy. VFI rather than placental volume may be a sensitive sonographic marker in the first trimester of GDM placentas.
Keywords: Gestational diabetes mellitus; placental vascular indices; placental volume; power Doppler; three-dimensional ultrasound.