Supplementary Material for: Renal Outcomes of Pregnant Patients with Immunoglobulin A Nephropathy: A Systematic Review and Meta-Analysis

Background: Is the prognosis of immunoglobulin A nephropathy (IgAN) influenced by pregnancy and delivery? The answer to this question still remains to be a controversial topic. Here, we undertook a systematic review and meta-analysis to obtain the overall estimate of potential effect of IgAN and pregnancy on each other. Methods: We systematically searched MEDLINE, EMBASE, Chinese Biological Medicine and Cochrane for cohort and case-control studies; a total of 1,378 articles were reviewed and 9 studies were included in the end. OR and mean difference (MD) were calculated with a random-effects model, kidney events and pregnancy outcomes were analyzed respectively. Results: The key finding of the meta-analysis of 145 renal events in 1,198 participants was that there was no difference in renal outcomes (defined as doubling of serum creatinine (SCr), 50% decline in glomerular filtration rate [GFR] and end-stage kidney disease) of pregnant women compared with non-pregnant women who had IgAN (OR 0.90; 95% CI 0.59–1.37; p = 0.63). Subgroup analysis indicated that there was no significant difference between the 2 groups according to sample size, follow-up year, age, level of SCr and proteinuria at baseline. There was no difference in the change of the eGFR/creatinine clearance rate (mL/min/1.73 m² per year) in IgAN patients with pregnancy compared with non-pregnancy (MD –0.11 mL/min; 95% CI –0.50–0.27; p = 0.57) as well. Women with IgAN had a higher likelihood of pregnancy outcomes compared with the Chinese general population, while they had a lower risk of preterm delivery, preeclampsia and low birth weight compared with those who had lupus nephritis or diabetic nephropathy. Conclusions: Pregnancy did not accelerate kidney disease deterioration in women with IgAN in stages of chronic kidney disease 1–3. Moreover, patients with IgAN had a relatively low risk of adverse pregnancy events compared with those with lupus nephritis or diabetic nephropathy.