Effect Of Pregnancy On The Subsequent Progression Of Diabetic Nephropathy

For years, there has been concern that the hyperfiltration, hypertension, or heavy proteinuria of pregnancy might damage glomeruli, tubules, and interstitium and accelerate the postpartum progression of DN to end-stage renal disease. In a pooled series of 195 women experiencing pregnancies with DN and having renal function assessed 1-10 years afterwards, 23% were in renal failure and 5.6% had died (table 4). Not surprisingly, the frequency of progression to renal failure after pregnancy was 49% in the group of women with impaired renal function in early pregnancy, compared to 7% if Cr was <134 uM or CrCl was >80 ml/min in early gestation (table 5) [38,95,96, 98,100,101,148,189-192]. A similar risk of post-pregnancy decline of renal function based on pre- or early pregnancy CrCl was also reported by Biesenbach, and he speculated that inadequate antihypertensive therapy may have contributed to the original and further decline in renal function [104].

Table 5. Course of diabetic nephropathy during and after pregnancy comparing patients with preserved vs impaired renal function in early pregnancy. Data pooled from references 95,96,190, 192,192 . Note the limited number of cases with severe azotemia in early pregnancy.

Initial renal function

Table 5. Course of diabetic nephropathy during and after pregnancy comparing patients with preserved vs impaired renal function in early pregnancy. Data pooled from references 95,96,190, 192,192 . Note the limited number of cases with severe azotemia in early pregnancy.

Initial renal function

Preserved

Impaired*

Cr >177

Number

70

57

(6)

Decline during pregnancy

12 (17%)

21 (37%)

(1)

Renal failure after preg**

4 of 57 (7%)

37 of 55 (49%)

(3)

Died

2 (3.5%)

5 (9.1%)

(0)

Three early studies assessed renal function after pregnancy in women with nephropathy [95,99,192]. All found that Cr Cl declined an average of about 10 ml/min per year, similar to the average rate in men and women with DN at that time [219-221]. More recently the annual decline in GFR in DN has improved to 2-5 ml/min/yr [222,223] due to advances in renoprotection [28]. Rossing and colleagues at the Steno Diabetes Center in Denmark conducted an observational study of female patients who developed DN in 1984-89 and were followed until death or the year 2000 [224]. Decline in Cr Cl over a median of 10 years postpartum was 3.2 + 3.4 ml/min/yr in 17 parous patients vs 3.2 + 5.1 ml/min/yr in 42 women never pregnant.

Other approaches have been used to examine the question of whether experiencing pregnancy hastens the progression of DN. With impaired renal function, the speed of progression to end-stage disease is little or no different whether a pregnancy is terminated in the first trimester or carried into the third trimester [95]. Miodovnik observed that increasing parity did not increase the risk of renal failure after pregnancy [192], and the EURODIAB Type 1

Complications Survey [225] and the Pittsburgh Epidemiology of Diabetes Complications case control study [226] found that parity did not increase the incidence of micro- or macroalbuminuria. In the Diabetes Control and Complications Trial, pregnancy had no effect on the end-of-study prevalence of albuminuria [53]. Purdy et al thought that 5 of 11 women with DN and moderate renal insufficiency had an accelerated rate of decline in renal function during pregnancy, but in follow-up for a mean of 2 years postpartum the group of 11 had slightly less decline in inverse Cr than 11 similar patients without pregnancy [101]. Mackie and colleagues [100] and Kaaja et al [227] also found no evidence for accelerated decline of renal function after pregnancy compared to non-pregnant patients. Therefore the medical practice of discouraging pregnancy in women with DN with mild-to-moderate impairment of renal function based on presumed increased risks of renal failure has no basis in published experience.

Delicious Diabetic Recipes

Delicious Diabetic Recipes

This brilliant guide will teach you how to cook all those delicious recipes for people who have diabetes.

Get My Free Ebook


Post a comment