Purpose Pregnancy is a known predisposing factor for central serous chorioretinopathy (CSC). Choroidal thickness (CT) increases in patients with CSC. This study was designed to evaluate CT in pregnant women. Patients and methods This was a prospective study. Fourteen healthy pregnant women and seven patients with pre-eclampsia were included. Twenty-one normal subjects were also recruited. CT was measured using enhanced-depth imaging optical coherence tomography.Results The mean CT of normal subjects, healthy pregnant women and patients with pre-eclampsia were 264.95 ± 21.03, 274.23 ± 29.30 and 389.79 ± 25.13 μm, respectively (normal subjects vs healthy gravidas: P40.05; normal subjects vs pre-eclampsia: Po0.001; healthy gravidas vs pre-eclampsia: Po0.001). CT decreased from 381.05 ± 22.96 μm to 335.17 ± 9.97 μm 1 week after delivery in patients with pre-eclampsia. Conclusions Pregnancy itself did not increase CT, whereas pre-eclampsia did appear to result in increased CT. This suggests that additional unknown factors induce hyperpermeability in pregnant women.