Changes in Retinal Microvasculature During Healthy Pregnancy Measured by AO.

BACKGROUND

Adaptive optics retinal imaging (rtx1e, Imagine Eyes, Orsay, France) enables high-resolution visualization of the retinal microvasculature, providing insights into systemic vascular health. Currently, no studies exist describing changes in wall-to-lumen ratio (WLR) during pregnancy, neither during the physiological course of pregnancy nor in pregnancy-associated complications.

METHODS

This single-center, prospective study at the Leipzig University Hospital, Germany, examines changes in retinal microvasculature by employing adaptive optics to calculate the WLR of an arteriole within a few seconds. The study examined a well-phenotyped cohort of 460 primarily White healthy singleton pregnancies, with 543 measurements taken from the first to the third trimester. The WLR was automatically determined using the nnUNet deep learning model.

RESULTS

Step-down selection mixed-effects modeling identified gestational week, maternal age, mean arterial pressure, and parity as significant contributors to WLR, whereas body mass index did not improve model fit. In the final model, advancing gestational week (P<0.001), higher maternal age (0.012), and higher mean arterial pressure (<0.001) were independently associated with increased WLR, whereas multiparous women showed significantly lower WLR values compared with nulliparous women, with negligible multicollinearity (variance inflation factor ≈1).

CONCLUSIONS

We identify WLR as a sensitive marker for imaging microvascular remodeling, serving as an indicator of adaptation to physiological pregnancy. Normal pregnancy is associated with an instant change of the retinal microvasculature indicated by an increase of WLR. Further studies are required to investigate the postpartum course of WLR and establish whether these changes are reversible.

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