Objective To investigate the incidence of retinal vein occlusion (RVO) in pregnant women and in the subpopulation of pregnant women with pre-eclampsia/eclampsia compared to that in the age-matched general female population to determine if there is increased risk of RVO in pregnancy. Design Nationwide population-based retrospective study using data entered into the Korean national health claims database from 2007 to 2011.Setting and Participants Of the incident RVO cases in the database, RVO cases that occurred during the pregnancyassociated period, which spanned a 52-week period from 40-weeks-before to 12-weeksafter childbirth, were identified. Of these cases, the presence of pre-eclampsia/eclampsia was determined. Main Outcome and Measure The standardized incidence ratios (SIRs) of RVO in the general pregnant population and in the pregnant population with pre-eclampsia/eclampsia were determined with respect to the age-matched general female population. Results Pregnancy-related RVO was identified in 33 cases from the 1.8 million women who experience childbirth during the study period, while the expected number of cases calculated by the direct standardization to the age-matched general population was 113. Of the 33 patients, 12 patients (36.4%) had pre-eclampsia or eclampsia. The SIR for the general pregnant population in reference to the age-matched general female population was 0.29 (95% CI, 0.20 -0.41). In contrast, the SIR for the pregnant population with pre-eclampsia/eclampsia in reference to the age-matched general female population and the age-matched general pregnant population was 67.50 (95% CI, 34.88-117.92) and 246.50 (95% CI, 127.37-430.59), respectively. Conclusions and Relevance The results suggest that pre-eclampsia/eclampsia is a risk factor for RVO, while pregnancy itself may not be a risk factor for RVO.