Pregnancy outcomes in patients with IgA vasculitis with nephropathy (Henoch-Schonlein purpura nephritis) and those with IgA nephropathy: Childhood purpura nephritis is high risk for preeclampsia

Objective: Childhood IgA vasculitis in remission is not a known risk factor for pregnancy but can lead to complications such as preeclampsia, even in women with a low risk of kidney function decline. Methods: This retrospective study compared pregnancy outcomes between patients with IgA vasculitis with nephropathy (Henoch-Schonlein purpura nephritis) and those with IgA nephropathy who delivered at Osaka University Hospital between 2010 and 2020. Results: Seven patients with purpura nephritis and 37 patients with IgA nephropathy had a total of 9 and 53 pregnancies, respectively. Purpura nephritis patients had an earlier gestational age at delivery and higher frequency of preterm birth, fetal growth restriction, and preeclampsia than IgA nephropathy patients, although differences were not significant. Among pregnancies at low risk of kidney function decline, 35 were with IgA nephropathy and 9 were with purpura nephritis. The incidence of preeclampsia was significantly higher with purpura nephritis (44%: 4/9) than with IgA nephropathy (9%: 3/35 including 2 with oocyte donation). Severe and early-onset preeclampsia was noted in 2 pregnancies with purpura nephritis. Conclusion: Patients with childhood purpura nephritis in remission may develop preeclampsia, with a higher risk of severe and early-onset preeclampsia than patients with IgA nephropathy.