Corneal Endothelial Cell Density and Morphology in Different Trimesters of Pregnancy

Objectives: To evaluate corneal endothelial cell density (CD) and morphology in different trimesters of pregnancy. Methods: This prospective study included 66 (66 eyes) pregnant women. The patient group was divided into three subgroups comprised of 22 women in the first, second, and third trimesters of pregnancy. An age-matched group of 22 (22 eyes) volunteers served as controls. Corneal measurements were performed using specular microscopy (Noncon Robo SP8000, Konan Medical). Central corneal thickness (CCT) and CD, hexagonal cell ratio (HEX), and coefficient of variation (CV) of the corneal endothelial cell layer of the patients were measured at each trimester. Results: Central corneal thickness did not change significantly during the pregnancy compared to controls (P>0.05). Endothelial CD was decreased in the first trimester and increased in the second and third trimesters, but the difference was not significant (P>0.05). Hexagonal cell ratio was decreased significantly in the first trimester (P<0.05). There was an increase in the second and third trimesters, which was not statistically significant (P>0.05). Coefficient of variation was increased significantly in the first trimester and showed a significant decrease in the second and third trimesters (P<0.05, respectively). Endothelial CD had a significant positive correlation with CV and HEX had a negative correlation with CV in the second trimester (r=0.438, P=0.041 and r=−0.822, P<0.001, respectively). Conclusion: Central corneal thickness and endothelial CD did not change significantly throughout the pregnancy. Hexagonal cell ratio and CV showed a significant but transient increase in the first trimester.