Evaluation of choroidal thickness and retinal nerve fiber layer thickness in Chinese pregnant women and healthy non-pregnant women

Purpose: To evaluate choroidal thickness and retinal nerve fiber layer (RNFL) thickness in different trimesters using enhanced depth imaging optical coherence tomography (EDI-OCT). Methods: A prospective comparative study included 45 healthy pregnant women in the first trimester, 45 women in the second, 45 women in the third and 45 healthy non-pregnant women as the control group. Macular choroidal thickness was measured at three locations: The subfoveal, 1 mm temporal, and 1 mm nasal from the fovea with EDI-OCT. Peripapillary choroidal thickness (PPCT) and RNFL thickness parameters were automatically calculated by the Spectralis OCT. Results: The subfoveal, temporal and nasal macular choroidal thickness were all significantly thicker in the second trimester, compared with those parameters in the first, the third trimesters and the control group (all P < 0.05). The PPCT was significantly increased in the second trimeter compared with the control group at global, temporal, temporal inferior, nasal and nasal inferior positions (all P < 0.05). The RNFL thickness was also significantly increased in pregnant women at nasal superior and nasal inferior quadrants (all P < 0.05). Conclusions: The choroidal thickness in pregnant women was found to be thicker than the control group, regardless of macular or optic disc location. Findings of RNFL thickening might indicate subclinical involvement of the central nervous system.