Retinal Vein Occlusion and Pregnancy, Pre-Eclampsia, and Eclampsia: The Results from a Nationwide, Population-Based Study Using the National Claim Database
March
Retinal Vein Occlusion and Pregnancy, Pre- Eclampsia, and Eclampsia: The Results from a Nationwide, Population-Based Study Using the National Claim Database
Sang Jun Park 0 1
Nam-Kyong Choi 0 1
Kyung Ha Seo 0 1
Kyu Hyung Park 0 1
Se Joon Woo 0 1
0 1 Department of Ophthalmology, Seoul National University College of Medicine, Seoul National University Bundang Hospital , Seongnam , Republic of Korea, 2 Medical Research Collaborating Center, Seoul National University Hospital and Seoul National University College of Medicine, Seoul, Republic of Korea, 3 Institute of Environmental Medicine, Seoul National University Medical Research Center , Seoul , Republic of Korea
1 Academic Editor: Fatima Crispi-Brillas, University of Barcelona , SPAIN
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Funding: This study was supported by the grants
(12-2013-019 and 14-2014-022) from the Seoul
National University Bundang Hospital Research
Fund. The funder had no role in study design, data
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
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
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.
collection and analysis, decision to publish, or
preparation of the manuscript.
Competing Interests: The authors have declared
that no competing interests exist.
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, 0.200.41). 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, 34.88117.92) 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.
Pregnancy and the subsequent puerperium represent hypercoagulable states with an increase
in thrombin levels and pro-coagulant factors and a decrease in the levels of the endogenous
anticoagulant protein S. The effects of progesterone on the blood vessel walls result in venous
stasis, even in normal pregnancy [1, 2]. The increased risk of thrombotic disorders during
pregnancy and puerperium has been consistently reported [1, 36]; therefore, an increased risk
of vision-threatening thrombotic conditions such as retinal vein occlusion (RVO) might also
be present. RVO is the second most frequently occurring retinal vascular disease and one of the
foremost sight-threatening conditions [710]. There have only been a few reports of
pregnancy-related RVO cases: 3 during normal pregnancy [1113], 1 during pregnancy with
preeclampsia [14], and 1 postpartum case following pregnancy with pre-eclampsia [15]. Despite
this limited evidence, pregnancy is generally considered a risk factor for RVO [16].
Recently, we conducted a nationwide epidemiologic study regarding the RVO incidence in
Korea using the national health claims registry [10]. Based on the gender-based incidence
within each 10-year age group, we observed a higher RVO incidence in women in addition to a
higher RVO incidence ratio (women:men) in those aged 2029 years compared to those aged
<20 years or 30 years.
Because of the known association between pregnancy and thromboembolic events, we
hypothesized that pregnancy may have influenced the incidence of RVO in women aged 2029
years in the previous study, an age at which pregnancy frequently occurs. Therefore, as a
follow-up to our previous study, we used the same data set to evaluate the association between
pregnancy and RVO [10].
We accessed health claims from the years 20072011 in the database of the national Health
Insurance Review and Assessment (HIRA) service of Korea; results from this data set have also
been published previously [10]. In brief, the HIRA reviews all of the health claims in Korea,
including those submitted through the Korean Natio (...truncated)