Is preterm delivery an independent risk factor for long-term maternal kidney disease?^*

Objective: To investigate whether women who had a preterm delivery (PTD) are at an increased risk of subsequent long term maternal kidney disease. Study design: A population-based study compared the incidence of long-term maternal kidney disease in a cohort of women with and without previous PTD. Deliveries occurred during a 25 years period, with a mean follow-up duration of 11.2 years. Results: Of 99 338 deliveries of women, 16 364 (16.4%) occurred in patients who had at least one PTD. A significant dose response was found between the number of previous PTDs and the gestational age at birth of the PTDs and future risk for renal-related hospitalizations. Patients with either spontaneous or indicated PTD had higher rates of renal-related hospitalizations (0.2% versus 0.1% OR= 2.6; 95%CI: 1.7–3.9, p <0.001 and 0.5% versus 0.2% OR 3.41; 95%CI: 1.7–6.5, p < 0.001, respectively). In a Cox proportional hazards model, PTD was independently associated with long-term maternal renal-related hospitalizations. Conclusions: PTD is an independent risk factor for long-term maternal kidney disease.