Correlation between treated hypertension in prepregnancy and transplanted kidney function deterioration during pregnancy even if within pregnancy permission criteria.

Neither pregnancy nor birth is easy in female patients with chronic renal failure, but after kidney transplantation, childbirth is possible when the graft function is good. There are few guidelines for pregnancy permission and multiple reports of decreased transplanted kidney function after pregnancy. In this study, we analyzed factors that influenced transplanted kidney function deterioration during pregnancy. Twenty-one women among 33 total pregnancies have given birth in our institution. Factors analyzed were donor and recipient age at transplantation, birth age of recipient, living or cadaveric donor, hemodialysis period before transplantation, delivery method, presence of hypertension and protein urea at the beginning of pregnancy, and period between pregnancy and transplantation. Maternal graft function at the beginning of the pregnancy was 1.16 ± 0.39 mg/dL (range = 0.5-2.1). A rise in serum creatinine (S-Cr) before delivery was observed in 10/21 cases: six cases showed a rise in S-Cr levels at 1 or more years after delivery. From the analysis, graft function at the beginning of pregnancy became a significant factor correlating with the elevation of S-Cr levels during pregnancy (P = .002). Patients were divided into two groups by S-Cr levels at the beginning of pregnancy: group A was S-Cr ≤ 1; group B was S-Cr 1-2 mg/dL. All group A cases showed stable graft function before and after delivery. Some individuals in group B experienced deterioration of graft function during pregnancy; the others had stable graft function. The presence of treated hypertension at the beginning of pregnancy in group B significantly impacted renal dysfunction during pregnancy (P < .05). In conclusion, the presence of treated hypertension at the beginning of pregnancy was a significant risk factor for functional deterioration of the transplanted kidney during pregnancy even if the individual was initially within pregnancy permission criteria.