The reference ranges of ophthalmic artery Doppler indices for singleton pregnancy at 20-24 weeks in Taiwan.

OBJECTIVE

Our study aims to establish the reference values of ophthalmic artery Doppler (OAD) indices for singleton pregnancies at 20-24 weeks in Taiwan and provide data on intraobserver reproducibility, as well as correlation of OAD indices, maternal factors, uterine artery pulsatility index (UtA-PI), and gestational age.

MATERIALS AND

METHODS

The data were collected during the second-trimester routine screening between December 2022 and March 2024. The exclusion criteria included maternal characteristics (smoking, systemic diseases, pregnancy-induced hypertension) and fetal findings during the routine visit (major fetal anomalies and small for gestational age). The correlation between OAD indices, UtA-PI, gestational age, and between the first and second measurements of unilateral OAD indices was assessed by using Spearman's correlation coefficient. Interobserver reproducibility was evaluated by Bland-Altman plots. Main characteristics of data distribution for the OAD indices are reported.

RESULTS

In total, 121 patients met the inclusion criteria during the study period. The Peak systolic velocity (PSV) ratio had a mean value of 0.51 ± 0.10. There was no significant correlation between OAD indices and gestational age or between OAD indices and UtA-PI (p > 0.05), even after adjusting for maternal age and BMI. OAD demonstrated excellent intraobserver reproducibility, and we found that recording OAD measurements from both eyes allows for the reduction of the variability.

CONCLUSION

Our study has established the reference values for OAD indices in singleton pregnancies at 20-24 weeks. OAD is promising in obstetrics, accessible, and easy to learn. It is crucial to raise awareness among clinicians and provide validation in the local settings. We want to translate the findings from the literature into our local settings and shift the focus from other biomarkers. Based on our results, it is important to apply local reference values to ensure the best quality of care. Our study provides a foundation for further validation and application for obstetrics screening in Taiwan.