Reference ranges for peak systolic velocity ratio of ophthalmic artery Doppler from first to third trimester based on serial Doppler measurements

Background: Maternal ophthalmic artery Doppler assessment has been proposed as one of the predictors for preeclampsia at any given time. Changes in ophthalmic artery Doppler preceding the onset of PE have been reported in several studies. Some parameters of ophthalmic artery Doppler studies have been proposed, but peak systolic velocity ratio is the most reliable indicator in the prediction of preeclampsia. However, limited previous studies have investigated the reference value across pregnancy. Study design: This was a prospective longitudinal cohort study of low-risk singleton pregnancies without evidence of fetal anomaly, visiting antenatal care between February 2024 and December 2024 at Maternal and Children Harapan Kita hospital in Jakarta and Dr. Sardjito hospital in Yogyakarta, Indonesia. Women were recruited from 11 weeks until 40 weeks gestation. They underwent serial ultrasound monitoring. Association of ophthalmic artery Doppler PSV was modeled with fractional polynomial regression. Equations for mean ± SD of the estimated curves were calculated, as well as GA-specific reference charts of centiles for ophthalmic artery PSV ratio from 11 + 0 weeks to 40 + 0 weeks. Result: We included 998 low-risk pregnancies and a total of 2439 ultrasound scans (median 3, range 2-4 per patient) were available for analysis. Goodness-of-fit assessment revealed that second-degree smoothing was the most accurate fractional polynomial for describing the course of ophthalmic artery PSV ratio curves. We observed a decrease in PSV ratio until 26 weeks and a substantial increase afterwards. The 3rd, 5th, 10th, 25th, 50th, 75th, 90th, 95th, and 97th centiles according to GA for ophthalmic artery PSV ratio are provided, as well as equations to allow calculation of any value as a centile. Conclusion: Ophthalmic artery PSV ratio showed non-linear behavior in which it decreased from 11 weeks until the end of trimester 2, and it started to increase until the end of pregnancy. © The Author(s) 2025.