The presence of IgA nephropathy (IgAN) is a serious consideration during pregnancy that can impact maternal and fetal outcomes. Close monitoring of blood pressure and proteinuria during pregnancy, along with multidisciplinary collaboration among the members of the care team, is essential to optimize clinical outcomes.

Pregnant women with IgAN face very specific risks, both maternal and fetal. One of the most important considerations during pregnancy is hypertension, since the incidence of hypertension during pregnancy is higher in patients with IgAN. For example, in a study from Japan, 69% of women with IgAN experienced hypertension in pregnancy compared with only 40% of those with other primary kidney diseases. Hypertension with IgAN can present in the presence of preeclampsia and in pregnant patients without preeclampsia, and it can portend a higher likelihood of a cesarean delivery, preterm delivery, and low fetal birth weight.

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In addition, women with IgAN who undergo kidney transplantation are at risk of deterioration of kidney allograft function during pregnancy. A study from Australia noted that one-third of pregnant transplant recipients had a deterioration in graft function, and a significant percentage of these patients did not return to baseline levels post partum. An interesting caveat is that this deterioration in renal allograft function is seen more frequently in patients with IgAN vs other kidney diseases.

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The onset of proteinuria during pregnancy can arise from various conditions, notably in the presence of underlying nephritis or preeclampsia, making it challenging to distinguish between them without a renal biopsy. Preeclampsia is characterized by new-onset hypertension with or without proteinuria occurring from 20 weeks of gestation to 12 weeks after delivery. In contrast, gestational proteinuria, which we often see even in the absence of IgAN, is defined as new-onset proteinuria without hypertension after 20 weeks of gestation that resolves by 12 weeks post partum. This is a really important distinction. In the absence of hypertension, these mothers can have renal diseases other than IgAN.

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It is very important to treat both the patient’s hypertension and their proteinuria. The goal for proteinuria in pregnant patients with IgAN is less than 300 mg over 24 hours, which is very close to the recommendations provided in the recent Kidney Disease: Improving Global Outcomes (KDIGO) guidelines for chronic kidney disease. Proteinuria is a validated marker of disease progression, so, with IgAN, in both nonpregnant and pregnant patients, we need to lower proteinuria so that these individuals can achieve full or partial remission.

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Steroids are typically used to treat pregnant patients with proteinuria due to IgAN in the first trimester. This is becoming a cornerstone of management. The other disease-modifying agents that we have to treat IgAN are not validated for use during pregnancy. The use of CCBs during the first trimester is safe to control blood pressure.

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We still have a lot of work to do in this space to better understand biomarkers that may portend bad outcomes for pregnant patients with IgAN. Research suggests that the presence of certain humoral factors, along with other clinical markers such as anemia and high circulating levels of IgM, may increase the risk of adverse renal events, but, again, more work is needed.