AIM: To quantitatively assess choroid vascular sublayers in women with pre-eclampsia(PE)compared to healthy pregnant women.METHODS: This cross-sectional observational study enrolled 100 subjects, including 40 healthy non-pregnant women, 23 healthy pregnant women, and 37 women with PE. Spectral-domain optical coherence tomography(SD-OCT)was used to measure the choroidal thickness(CT)at the fovea and four additional sites that were 750 μm nasal/temporal or 1 500 μm nasal/temporal to the fovea, and designated as subfoveal choroidal thickness(SFCT), N750, T750, N1500, and T1500, respectively. The thickness of two choroidal vessel layers, Sattler's and Haller's layers, also were quantitatively assessed. RESULTS: No significant differences in mean age or spherical equivalent were observed among the three groups(P=0.240, 0.338). No difference was observed in gestational ages between the healthy pregnant women and PE patients(P=0.783). Significant differences were observed in large choroidal vessel thickness(LCVT), medium choroidal vessel thickness(MCVT), and SFCT at the five sites among the three groups(P<0.05). Compared with normal non-pregnant women, a significant increase in LCVT, MCVT, and SFCT was detected at the five sites in healthy pregnant women(P<0.05). LCVT and SFCT in PE patients were significantly greater at the five sites compared to normal pregnant women(P<0.05), while MCVT was not different(P=0.709).CONCLUSION: This study demonstrated that the vascular sublayer thickness of the choroid was significantly increased in pregnancy and PE. Moreover, the increase in CT thickness might be due to the thickening of Haller's layer. We also observed that the nasal CT increased more than the temporal CT in PE patients and normal pregnant women. We suggest that parasympathetic and sympathetic mediated regulation and nonvascular smooth muscle cells might play a role in the choroidal vascular sublayer thickness variations observed in pregnancy and PE.