Changes in Choroidal Thickness During Pregnancy Detected by Enhanced Depth Imaging Optical Coherence Tomography

Aim: To compare the choroidal thickness measurements of healthy pregnant women obtained in the first trimester with measurements obtained in the third trimester using enhanced depth imaging optical coherence tomography (OCT).

Methods: 54 eyes of 27 healthy pregnant women and 50 eyes of 25 age matched healthy women were enrolled in this observational, cross-sectional study. The pregnant women underwent two OCT scans, one in the first trimester at gestational weeks 6-8, and the other during the third trimester at gestational weeks 32-37; the control group had OCT scanning during the follicular phase of the menstrual cycle, using the enhanced depth imaging mode. Choroidal thicknesses were measured at the fovea, at three locations nasal, and at three locations temporal to the fovea at 500 μm intervals.

Results: The choroidal thickness measurements obtained in the third trimester were significantly decreased in all measured points in both eyes compared to the measurements obtained in the first trimester (p<0.05). At the fovea, the mean (±SD) choroidal thickness measured in the first trimester was 349.22±82.11 μm in the right eyes and 341.30±85.22 μm in the left eyes, which decreased to 333.56±76.61 μm in the right eyes (p=0.014) and 326.93±75.84 μm in the left eyes (p=0.024) in the third trimester. Although not statistically significant, choroidal thicknesses of the control group were less than the choroidal thicknesses of the pregnant women (p>0.05).

Conclusions: Choroidal thickness was found to be significantly decreased in healthy pregnant women during the third trimester compared to the first trimester. This finding can provide valuable information when interpreting pregnancy related ocular disorders.