Many times, primary GN presents during pregnancy and diagnosis is tough. Other times, patients with known primary GN get pregnant. Three questions come to mind.
1. Does the pregnancy change the natural course of the glomerular disease?
A study done in over 120 pregnancies looked at this question. The clinical course of 123 pregnancies in 86 patients with biopsy-proven glomerular diseases was evaluated. No complications were observed in more than half of the pregnancies. The lowest incidence of complications was observed in patients with membranous nephropathy and the highest in membranoproliferative glomerulonephritis(MPGN) patients. Renal function deteriorated in 10 cases during pregnancy. The authors note that in most patients pregnancy did not change the natural history of glomerular disease.
2. What are the risk factors in GN with pregnancy for maternal and fetal outcomes?
Hypertension and impaired renal function at conception seem to carry increased risk for mothers and fetuses. A study done at a single center looked at these complications. 24 pregnancies in 17 women with biopsy-proven glomerular disease was analyzed. The underlying renal histology was IgA nephropathy in 8 cases, lupus nephritis in 7, MPGN in 1, and focal segmental glomerulosclerosis in 1.
Fetal survival rate was 75%. The perinatal mortality was 5.5%. De novo hypertension occurred in 8 pregnancies (33.3%). In 11 pregnancies (46%) increased proteinuria was diagnosed and in 6 (25%) a decline in maternal renal function was recorded. Maternal hypertension and renal function impairment were found to lead to more ob complications.
3. Which GN fare the worse?
Many GN have been reported with pregnancy( Membranous GN, MCD, MPGN, IgA, FSGS). A single center study looked at outcomes based on type of GN in pregnancy. In all cases diagnoses were established by biopsy before pregnancy. They were: MPGN in 16 patients, focal glomeruloesclerosis in 13, IgA nephropathy in 10, membranous nephropathy in seven and focal glomerulonephritis in two women. Women with membranoproliferative glomerulonephritis appeared to fare worse, and those with IgA nephropathy and membranous nephropathy better than the rest.