Ophthalmic artery Doppler in prediction of pre‐eclampsia at 35–37 weeks' gestation

OBJECTIVES First, to examine the potential value of maternal ophthalmic artery Doppler at 35-37 weeks\u0027 gestation in the prediction of subsequent development of pre-eclampsia (PE), and, second, to examine the variability between repeat measurements in the same eye and variability in measurements between the two eyes. METHODS This was a prospective observational study in women attending for a routine hospital visit at 35 + 0 to 36 + 6 weeks\u0027 gestation. The visit included recording of maternal demographic characteristics and medical history and assessment of flow velocity waveforms from the maternal ophthalmic artery. Waveforms were obtained in sequence from the right eye, left eye and again from the right and then left eye. We recorded the average of the four measurements, two from each eye, for the following four indices: first peak of systolic velocity; second peak of systolic velocity; pulsatility index; and the ratio of the second to first peak of systolic velocity (PSV ratio). The measurements of the four indices were standardized to remove the effects of maternal characteristics and elements from the medical history. The competing-risks model was used to determine the detection rate (DR) of delivery with PE at any time and at \u003c 3 weeks after assessment, at a 10% false-positive rate (FPR), in screening by maternal factors alone and a combination of maternal factors and the adjusted value of each of the four ophthalmic artery indices. RESULTS The study population of 2287 pregnancies contained 60 (2.6%) that developed PE, including 19 (0.8%) that delivered with PE at \u003c 3 weeks after assessment. The DR, at 10% FPR, of delivery with PE at any time after assessment by maternal factors was 25.0% (95% CI, 14.7-37.9%), and this increased by 25 percentage points to 50.0% (95% CI, 36.8-63.2%) with the addition of the adjusted PSV ratio (P = 0.005); the respective values for delivery with PE at \u003c 3 weeks after assessment were 31.6% (95% CI, 12.6-56.6%) and 57.9% (95% CI, 33.5-79.8%). The other ophthalmic artery indices did not improve the prediction provided by maternal factors alone. There was good correlation between the first and second measurements of PSV ratio from the same eye (right eye r = 0.823, left eye r = 0.840), but poorer correlation in the first and second measurements between the two eyes (first measurement r = 0.690, second measurement r = 0.682). In screening by maternal factors and PSV ratio for PE with delivery at any stage after assessment, the estimated DR, at 10% FPR, was 50.0% when the average of four measurements was used (two from each eye), 49.1% when the average of one measurement from each eye was used, 47.3% when the average of two measurements from the same eye was used, and 45.8% when only one measurement was used. CONCLUSIONS Ophthalmic artery PSV ratio at 35-37 weeks\u0027 gestation can predict subsequent delivery with PE, especially if this occurs within 3 weeks after assessment. In the assessment of ophthalmic artery Doppler, it is necessary to use the average of one measurement from each eye to minimize variability of measurements. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.