Association between Parity and Prevalence of CKD

Background: Previous studies have demonstrated that women with a history of adverse pregnancy outcomes, such as eclampsia, are at increased risk of developing chronic kidney disease (CKD). However, only a limited number of studies investigated the association between parity and CKD. Under the assumption that physiologic and anatomic changes during pregnancy, such as in glomerular filtration rate, renal plasma flow, renin-angiotensin-aldosterone system and size of kidneys could impact on kidney, we investigated whether the number of parity affects the prevalence of CKD. Methods: We analyzed the health examinee data from the Korean Genome and Epidemiology Study (KoGES-HEXA), which comprises participants from Korea between 2004 and 2013. After excluding individuals with histories of pre-existing CKD and participants with incomplete records, 100,433 participants were included in this study. CKD was defined as an estimated glomerular filtration rate below 60 mL/min/1.73 m2, calculated using the CKD-EPI (Epidemiology Collaboration) formula or the presence of proteinuria. We compared the prevalence of CKD across four groups, categorized by the number of parity; 0, 1, 2, and ≥3. Results: Women with 3 or more parities, compared to those with no parity, were older with more co-morbidities, less likely to smoke or drink, and had higher body mass index, elevated fasting blood sugar and low density lipoprotein cholesterol. CKD prevalence seemed higher in women with three or more parities than in no parity group (5.3% vs. 3.1%, P<0.05), but this association disappeared after adjusting for risk factors (Figure 1). Among women with a history of eclampsia, 1 and 2 parity groups showed higher risk of CKD compared to 0 parity group (Figure 1). Conclusion: Exposure to eclampsia was associated with higher risk of CKD. On the other hand, parity may not independently affect the prevalence of CKD in Korean women. Further studies are needed to determine whether parity itself increases the prevalence of CKD.