Effect of pregnancy on diabetic nephropathy and retinopathy

To determine whether pregnancy worsens renal function in women with diabetic nephropathy and the effect of pregnancy on diabetic retinopathy.

Cross-sectional analytical study.

The study was conducted in OPD, Bahawal Victoria Hospital, Bahawalpur from September 1997 to June 2003.

Thirty-five patients (aged 20-36 years ) identified with diabetic nephropathy and moderate to severe renal dysfunction(creatinine [Cr] > 1.4 mg/dl) at pregnancy onset by retrospective chart review. Alterations in glomerular filtration rate (GFR) were estimated. An equal number of non-pregnant premenopausal type I diabetic women with similar degrees of renal dysfunction served as controls for non-pregnant rate of decline of renal function and potential contributing factors. Student's t-test and repeated measures analysis of variance were analyzed.

Mean serum Cr rose from 1.8 mg/dl prepregnancy to 2.5 mg/dl in the third trimester. Renal function was stable in 27%, showed transient worsening in pregnancy in 27%, and demonstrated a permanent decline in 45%. Proteinuria increased in pregnancy in 79%. Exacerbation of hypertension or pre-eclampsia occurred in 73% and 71% of these showed acceleration of disease during the pregnancy. All the patients had diabetic retinopathy, though proliferative retinopathy was diagnosed and treated in only 54.5.% prepregnancy. The retinopathy progressed, requiring laser therapy, in 45.4%. Macular edema was noted in 6 of the patients. Other diabetic complications included peripheral and autonomic neuropathy in 8 patients.

Pregnancy induced progression is seen in the decline of renal functions. Patients with diabetic nephropathy were found to have a > 40% chance of accelerated progression of their disease as a result of pregnancy. Forty-five percent of the patients had permanent decline in GFR in association with pregnancy.