MATERNAL OPHTHALMIC ARTERY DOPPLER VELOCIMETRY AT 35–37 WEEKS' GESTATION FOR SHORT-TERM PREDICTION OF PREECLAMPSIA: A PROSPECTIVE OBSERVATIONAL COHORT STUDY

Abstract

Objective: Late-onset preeclampsia (PE) accounts for the majority of cases yet remains difficult to anticipate using conventional risk assessment. We investigated whether maternal ophthalmic artery Doppler velocimetry performed at 35–37 weeks' gestation could identify women at imminent risk of PE, and compared the discriminatory performance of individual Doppler indices for prediction within a three-week interval. Methods: In this prospective observational cohort study, 230 women with singleton pregnancies underwent standardized transorbital ophthalmic artery Doppler assessment during routine ultrasound examination between 35 + 0 and 36 + 6 weeks. First and second peak systolic velocities (PSV1, PSV2), pulsatility index (PI), resistance index (RI), and the PSV2/PSV1 ratio were recorded. Pregnancy outcomes were ascertained prospectively, and the capacity of each parameter to predict PE occurring within three weeks of assessment was evaluated by receiver-operating-characteristic (ROC) curve analysis, with detection rates (DR) reported at a fixed 10% false-positive rate (FPR). Results: PE developed in 26 of 230 pregnancies (11.3%). Maternal demographic and anthropometric characteristics did not differ meaningfully between outcome groups. All ophthalmic artery Doppler indices were significantly deranged in pregnancies destined to develop PE. At a fixed 10% FPR, three-week DRs were 40% for PSV1, 45% for PSV2, 50% for PI, and 66% for the PSV2/PSV1 ratio, which also yielded the highest area under the ROC curve (AUC 0.76; PSV1 0.62, PSV2 0.65, PI 0.68). Conclusion: Ophthalmic artery Doppler assessed in the late third trimester carries moderate short-term predictive value for PE. The PSV2/PSV1 ratio, a marker relatively insensitive to insonation angle, outperformed conventional impedance and velocity indices and warrants further evaluation as a component of late-pregnancy surveillance protocols rather than as an isolated screening test.