Refer to nephrologist!

Severe preconceptional renal dysfunction, as evidenced by a reduced GFR and elevated serum creatinine, can significantly deteriorate during pregnancy and may not be reversible. Therefore:

R 1.6a Suggest assessment by nephrologist for both baseline renal assessment and to review the woman’s specific risk of worsening renal function in the event of pregnancy. (ungraded) 

R1.7c In severe renal dysfunction, advise about possible loss of control and worsening if ACE and angiotensin-receptor blockers will be stopped. If medication continues, advise about possible teratogenesis. (ungraded)