Pregnancy in patients with type 1 diabetes and diabetic nephropathy: sailing between Scylla and Charybdis

Background Pregnancy in women with type 1 diabetes (T1D) complicated by overt diabetic nephropathy (DN) remains a major clinical challenge, with limited data on maternal-foetal outcomes. This study describes the clinical course and outcomes of pregnancies in women with overt DN followed in a dedicated nephrology-obstetric care setting. Methods We conducted a retrospective analysis including 15 pregnancies, 13 of which had complete baseline and delivery data, in women with T1D and overt DN followed at Policlinico Umberto I (Rome-Italy), between 2010 and 2022. Maternal characteristics, renal and obstetric complications, and perinatal outcomes were analysed from baseline to six months postpartum. Results Thirteen pregnancies were analysed. Median baseline estimated glomerular filtration rate (eGFR) was 67.6 (42.9-95.8) ml/min/1.73m2, median proteinuria 0.8 (0.5-1.6) g/day; 69% had chronic hypertension and 84% diabetic retinopathy. Proteinuria increased during pregnancy in 9/13 cases. Two patients developed acute kidney injury, one of whom required haemodialysis during pregnancy and remained dialysis-dependent thereafter. Superimposed preeclampsia occurred in five cases and was associated with lower baseline eGFR. Preterm delivery was common; all the patients delivered by caesarean section. A decline ≥10 mL/min/1.73 m2 in eGFR or dialysis initiation was observed in 4 patients at 6-month follow-up; in the remaining patients, no significant changes were observed, although the follow-up was limited to 6 months. Conclusions Pregnancy in women with overt DN continues to entail substantial maternal and foetal risk. Early nephrology referral, strict metabolic and blood pressure control, and systematic preconception counselling are crucial to optimising outcomes and preventing irreversible renal decline.