What is the Effect of chronic kidney disease on fertility and pregnancy?
Fertility is decreased in women with preexisting kidney disease. Since the denominator (number of women with kidney disease trying to become pregnant) is not known, it is impossible to know how much fertility is decreased, but it is unusual to see a pregnancy in a woman with a serum creatinine >2.5 mg/dL. In women with kidney disease and preserved glomerular filtration rate (GFR), pregnancy carries an increased risk of hypertension and premature delivery. If proteinuria is present, it is likely to increase during pregnancy. It can be difficult to distinguish between hypertension associated with kidney disease and preeclampsia, since increased proteinuria, increased uric acid, and increased creatinine may be seen in both. One complication of pregnancy in a woman with kidney disease is worsening kidney function. The likelihood of worsening kidney function depends on the level of kidney function before conception. Most studies rely on serum creatinine to assess kidney function. The risk of worsening kidney function increases when the serum creatinine is >1.4 mg/dL. If the serum creatinine is >2 mg/dL, the risk of worsening kidney function is 30% to 50%. Imbasciati et al. used eGFR and proteinuria in assessing kidney disease. Worsening kidney function was seen only in women with both a GFR of <40 cc/min and at least 1 g of proteinuria in 24 hours. The formulas used to calculate GFR have not been validated in pregnancy.
