First-trimester uterine artery Doppler examination in pregnancies complicated by gestational diabetes mellitus with or without pre-eclampsia.

OBJECTIVES: To assess first-trimester placental perfusion, reflected in the uterine artery (UtA) pulsatility index (PI), in pregnancies complicated by gestational diabetes mellitus (GDM), with or without pre-eclampsia (PE), compared with those unaffected by GDM.

METHODS: UtA-PI was measured at 11 + 0 to 13 + 6 weeks' gestation in 1037 singleton pregnancies that subsequently developed GDM and in 56 649 normoglycemic controls. The measured mean UtA-PI was converted to multiples of the expected normal median (MoM), corrected for maternal weight, racial origin and gestational age, and the median MoM values in the two groups were compared.

RESULTS: The incidence of PE was higher in pregnancies with GDM than in controls (4.0% vs 2.3%, respectively; P =  0.001). However, there were no significant differences in the median UtA-PI MoM between the groups (1.00 (interquartile range (IQR), 0.82-1.21) vs 1.00 (IQR, 0.81-1.21); P = 0.73). The median UtA-PI in patients who developed PE was higher than in those who did not develop PE, regardless of the development of GDM.

CONCLUSIONS: First-trimester placental perfusion, as assessed by UtA Doppler examination, is not impaired in women who subsequently develop GDM. The increased prevalence of PE in women with GDM cannot be attributed to impaired placentation.