Abstract
BACKGROUND: Fetal growth restriction (FGR) constitutes a major contributor to perinatal morbidity and mortality. To investigate gestational changes in maternal arterial stiffness during mid-to-late pregnancy and validate predictive models for FGR using maternal arterial stiffness indices and maternal and fetal Doppler measurements. METHODS: This prospective observational study enrolled singleton pregnancies undergoing routine mid-to-late trimester assessments. Data collection included maternal demographics, maternal non-invasive arterial stiffness measurements [arterial pressure volume index (API) and arterial velocity pulse index (AVI)], and maternal and fetal hemodynamic parameters. Regression analyses with backward elimination and restricted cubic spline models were employed to identify FGR predictors. Cox proportional hazards models quantified associations between API and FGR risk. RESULTS: Among 573 participants (age 18-44 years), 35 (6.1%) developed FGR. The API decreased with increasing gestational age, particularly with a particularly rapid decrease observed between 20.4 weeks and 31.1 weeks, which may be related to pulse pressure (r = 0.599, p < 0.001), uterine artery pulsatility index (PI) (r = 0.191, p < 0.001), and umbilical artery PI (r = 0.168, p < 0.001). The API was significantly higher in pregnant women with early-onset FGR compared to both the control group with gestational age < 32 weeks (mean = 29.12 ± 7.46 vs. 24.66 ± 4.09, t = -4.239, p < 0.001) and the late-onset FGR group (mean = 29.12 ± 7.46 vs. 23.28 ± 3.59, t = 2.978, p = 0.005). Multivariable analysis identified the API as an independent early-onset FGR predictor (adjusted OR 1.174, 95% CI 1.053-1.309, p = 0.004). The pregnant women (at gestational age < 32 weeks) with API > 95th percentiles exhibited 7.131-fold increased early-onset FGR risk (95% CI 2.022-25.155). The optimal API cutoff value to indicate early-onset FGR was 30, with a sensitivity 55.56% and specificity 92.55%, and an area under the curve of 0.789 (95% CI 0.674-0.903). CONCLUSION: We found that maternal peripheral arterial stiffness decreases with increasing gestational age, which may be related to changes in maternal hemodynamics. Notably, mothers with early-onset FGR fetuses have higher peripheral arterial stiffness compared to those with normal pregnancies, and high API is an independent risk factor for early-onset FGR.