Neonatology

Long-Term Risk for Chronic Kidney Disease After Premature Birth

Prematurity and extreme prematurity were associated with doubled and tripled risks, respectively, for CKD from childhood into mid-adulthood.

Because much of nephrogenesis occurs late in gestation, what is the impact of premature birth upon renal function later in life?

To address this question, researchers used Swedish birth and health registries to examine the risk for chronic kidney disease (CKD) in childhood through mid-adulthood among 4.2 million residents by birth term status: extremely preterm (22–27 weeks, very preterm (28–33 weeks), late preterm (34–36 weeks), early term (37–38 weeks), term (39–41 weeks), and post-term (≥42 weeks). Results were as follows:

• CKD developed in 4305 individuals (0.1%) during 87 million person-years of follow-up.
• Incidence rates of CKD were 9.2 per 100,000 person-years for all preterm births combined, 5.9 for early term, and 4.5 for term births.
• Individuals born extremely preterm had a threefold greater risk for developing CKD compared with those born at term.
• Among individuals with neonatal acute kidney injury, 24% developed CKD.
• Preterm birth was associated with a fivefold greater risk for developing CKD before age 10 years compared with term birth.
• The presence of congenital anomalies was associated with a 20-fold greater incidence of CKD. Other risk factors were male sex, maternal obesity, and maternal preeclampsia.
• Among siblings, the association between prematurity and risk for CKD was maintained, suggesting that the association was not genetically or environmentally determined.

COMMENT

Premature birth carries a significant risk for later kidney disease. When we care for children who were born premature, we should monitor the urinalysis, measure blood pressure, and periodically check the serum creatinine. Proteinuria and hypertension are especially important early signs of kidney injury.

(F. Bruder Stapleton, MD reviewing Crump C et al. BMJ 2019 May 1)