Lack of Association Between Middle Cerebral Artery Diastolic Deceleration Area and Gestational Diabetes Mellitus: A Prospective Case-Control Study

Backgroud and Objectives: To evaluate conventional Doppler indices and the novel middle cerebral artery (MCA) diastolic deceleration area (DDA) in pregnancies complicated by gestational diabetes mellitus (GDM), and to explore their associations with perinatal outcomes. Prospective case–control study conducted at a tertiary referral perinatology center. Materials and Methods: The study included 83 women with GDM and 92 healthy controls. Standard fetal biometric and Doppler parameters—umbilical artery, MCA, ductus venosus, cerebroplacental ratio, and umbilicocerebral ratio—were assessed, alongside calculation of MCA DDA. Perinatal outcomes were recorded. Results: Most conventional Doppler indices did not differ between groups, except for lower MCA dicrotic notch velocity and higher ductus venosus time-averaged maximum velocity in the GDM group. MCA DDA values did not differ significantly between GDM and control groups (6.67 [5.02–8.20] vs. 7.05 [5.21–8.39] cm·s, p = 0.444) and showed no difference between insulin- and diet-controlled subgroups (p > 0.05). MCA DDA showed significant correlations with gestational age, MCA peak systolic velocity, and birth weight. However, after adjustment for potential confounders, gestational age remained the only independent determinant of MCA DDA. The multivariable analysis evaluating composite adverse neonatal outcomes was limited by the small number of adverse events (n = 14). Conclusions: MCA DDA did not differ between GDM and control pregnancies and primarily reflected gestational age-related physiological variation rather than diabetes specific hemodynamic changes. However, its relationship with adverse neonatal outcomes remains uncertain and requires further investigation in larger prospective studies.