(886) Umbilical Vein Spectral Analysis to Predict Hypertensive Disorders of Pregnancy and Maternal Vascular Malperfusion

While the umbilical vein (UV) carries nutrient-rich blood to the fetus, conventional UV Doppler techniques have not provided an effective tool for assessing placental function. We present a UV Doppler-based workflow to predict placental dysfunction, including hypertensive disorders of pregnancy (HDP), small-for-gestational-age (SGA), maternal vascular malperfusion (MVM), and fetal vascular malperfusion (FVM), by quantifying maternal-to-fetal spectral power.

Study Design:

UV Doppler waveforms were acquired at 18-24 weeks gestation in a prospective cohort study of singleton pregnancies. Sonographers were instructed to obtain 1-3 extended-duration cine clips of UV Doppler near the placental cord insertion. Frames of cine clips were stitched into long sequences using OpenCV’s feature-based pipeline to improve spectral resolution. UV Doppler envelopes were extracted using Rubin’s method (Fig 1a). Welch’s method was applied for spectral estimation due to its robustness to envelope variation caused by fetal motion or maternal breathing. The log ratio of the spectral peaks at the maternal and fetal heart rates (LRSP) was assessed as a predictor of placental dysfunction.

Results:

70 subjects were included in the analysis, with a mean of 1.77 cine clips (SD = ±0.59) per subject, each lasting an average of 6.89 seconds (SD = ±1.81). Cohort details are provided in Table 1. LRSP was significantly higher in pregnancies that later developed HDP (p = 0.0181, AUC = 0.7) and in those with MVM (p=0.0436, AUC=0.8) (Fig 1bc). This indicates a greater relative contribution of maternal power to the UV Doppler in pathological cases compared to healthy subjects. No significant association was found with SGA (p=0.17) or FVM (p=0.78).

Conclusion:

UV Doppler spectral estimation can be used to assess the relative maternal and fetal contributions to UV flow patterns and may serve as a non-invasive early marker of  placental dysfunction. Current validation includes 4 confirmed MVM cases; ongoing pathology follow-up and larger cohorts are expected to further establish the method’s predictive value.