What is the effect of lupus nephritis on pregnancy and vice versa?
Lupus occurs most frequently in women of child-bearing age and may be diagnosed during pregnancy.
When the onset of lupus nephritis occurs during pregnancy, the kidney histology is often World Health Organization (WHO) class IV, which requires prompt treatment.
New-onset lupus is one of the indications for a kidney biopsy in a pregnant woman, since the drugs most commonly used for severe lupus nephritis such as cyclophosphamide should not be used in early pregnancy.
In a woman with diffuse proliferative lupus nephritis, high-dose steroids can be used initially. Oral cyclophosphamide has been used in women beyond 20 weeks gestation, but long-term follow-up is limited. Lupus nephritis, including membranous lupus nephritis, carries the risk of relapse during pregnancy. The risk of relapse is lowest if the woman has been in remission 6 months before pregnancy but even then, one-third of women have a flare during pregnancy and during the first 6 weeks postpartum. The greatest risks may come from extrarenal lupus. Many antibodies associated with lupus are immunoglobulin G (IgG) and cross the placenta. They may cause rash and thrombocytopenia in the infant during the first 6 months of life. Anti-Sjögren’s-syndrome-related antigen A (anti-Ro) (anti-SSA) antibody is associated with congenital heart block.
