Risk factors of adverse pregnancy outcomes in patients with immunoglobulin A nephropathy

Pregnancy and childbirth are major concerns for women with immunoglobulin A nephropathy (IgAN), because it peaks in their child-bearing age. To provide evidence for optimal pre-conception care, we investigated whether the disease control status, assessed by blood pressure and/or urine protein level, is associated with adverse pregnancy outcomes. This case-control study used data from 924,238 patients with chronic kidney disease obtained from a hospital claims database. We included 297 pregnancies with IgAN and collected data on antihypertensive medications and glucocorticoid therapy within six months before conception as the exposures. The outcomes were hypertensive disorders of pregnancy (HDP) that required intravenous nicardipine and preterm delivery. We estimated the adjusted odds ratios (aORs) using multivariable logistic regression. The prescriptions of antihypertensive medications other than renin-angiotensin-aldosterone system inhibitors (RASi) were significantly associated with both severe HDP requiring intravenous nicardipine (aOR: 5.01, 95% confidence interval [CI]: 1.43-17.5) and preterm delivery (aOR: 6.45, 95% CI: 1.81-23.0), compared with those of only RASi. No significant associations were observed between glucocorticoid therapy and outcomes. Regarding pre-conception care, our findings suggest that pre-conception antihypertensive medication use, as a surrogate marker for underlying hypertension, may help identify women with IgAN at higher risk of adverse pregnancy outcomes.