Underlying renal disease is significant risk factor for the development of pre-eclampsia. Tacrolimus, a calcineurin inhibitor, is a common immunosuppressant medication used in solid organ transplant and autoimmune diseases. It is viewed as one of the safer immunosuppressant medications to use in pregnancy. Although Tacrolimus levels usually fall in pregnancy, recent literature suggests that unbound levels may actually rise. This is a case series of three women on Tacrolimus who were admitted to hospital with suspicion of pre-eclampsia. Features included worsening of hypertension, acute rise in creatinine and significant worsening of proteinuria in two cases. With judicious reduction of Tacrolimus dosing, the blood pressure, creatinine and proteinuria returned to baseline and the pregnancies continued. Tacrolimus nephrotoxicity should be included in the differential
diagnoses of pregnant women taking this medication who present with high blood pressure, raised creatinine and proteinuria.