#4946 PREVALENCE OF CHRONIC KIDNEY DISEASE IN WOMEN OF REPRODUCTIVE AGE AND OBSERVED BIRTH RATES

Abstract

Abstract Background and Aims Women of reproductive age with chronic kidney disease (CKD) are recognised to have decreased fertility and a higher risk of adverse pregnancy outcomes, such as hypertensive diseases, preterm birth and longer hospital stays. How often CKD afflicts women of reproductive age and how many pregnancies are affected is not well known. This study aimed to evaluate the burden of CKD and associated birth rates in an entire region. Method This was a retrospective cohort study including women of childbearing age in Stockholm during 2006–2015. We estimated the prevalence of CKD by the presence of an ICD-10 diagnosis of CKD, a single estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2 or history of maintenance dialysis. By linkage with the Swedish Medical Birth Register we identified births during the subsequent three years from study inclusion and evaluated birth rates. For CKD prevalence, we reported overall counts and the age-averaged prevalence to adjust for the uneven age distribution in the cohort. A linear regression model was fitted to identify the increase in prevalence and 95% confidence interval (CI) per additional year in age. Birth rate was calculated per 1000 person years. All analyses were performed using R version 4.2.1. Results We identified 817,730 women in our region, of whom 55% had at least one creatinine measurement. A total of 3938 women were identified as having CKD, providing an age-averaged CKD prevalence of 0.50%. Women with probable CKD showed a lower birth rate 3 years after the index date (35.7 children per 1000 person years) than the remaining women free from CKD (46.5 children per 1000 person years). Conclusion As many as 0.50% of individuals in this cohort had CKD, defined on the basis of at least one eGFR<60 ml/min1.73 m2 test result, dialysis treatment (i.e. CKD stages 3–5) or an ICD-10 diagnosis of CKD. This prevalence is lower than previous estimates. Women with CKD had a lower birth rate than those without CKD, illustrating the challenges of this population to successfully conceive. Future research should be done to identify impeding factors.