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Premature birth may significantly increase risk for CKD later in life

A recent study found that preterm and early birth were strong risk factors for the development of chronic kidney disease from childhood to mid-adulthood, and those born prematurely should receive long term follow-up to preserve renal function over their lifetime.

“Preterm birth (< 37 gestational weeks) interrupts the development and maturation of the kidneys during a critical growth period,” Casey Crump, MD, PhD, professor in the departments of family medicine and community medicine at the Icahn School of Medicine at Mount Sinai, and colleagues wrote. “The third trimester of pregnancy is the most active period of fetal nephrogenesis, during which more than 60% of nephrons are formed. Interruption of this process results in a lower nephron endowment that is lifelong.”

To determine if preterm birth increases risk for CKD later in life, researchers used the Swedish birth registry to collect data from nearly all births in the country from 1973 to 2014. Researchers then identified singleton preterm births to include in the study cohort. Additional Swedish registries were used to identify patients who developed CKD between birth and Dec. 31, 2015.

Researchers used Cox regression to determine the risk for CKD in those born prematurely. If sibling data were available, researchers performed co-sibling analyses to compare results of births with different gestational ages within a family and to determine the influence of shared genetic and environmental factors on CKD risk.

A total of 4,305 participants with CKD were identified in the study. The overall incidence rate of CKD was 4.95 per 100,000 person years in all ages examined (0-43 years), with a full-term birth incidence rate of 4.47 per 100,000 person years. Preterm birth was associated with a CKD incidence rate of 9.24 per 100,000 person years, nearly double the rate for full-term birth. Extremely preterm birth (< 28 gestational weeks) had nearly triple the risk for CKD, with an incidence rate of 13.33 per 100,000 person years. Early-term birth (37-38 gestational weeks) had a CKD incidence rate of 5.9 per 100,000 person years.

The strongest association between preterm birth and CKD was observed in those aged 0 to 9 years (HR = 5.09; 95% CI, 4.11-6.31). Preterm birth was also associated with a significantly increased risk for CKD in those aged 10 to 19 years (HR = 1.97; 95% CI, 1.57-2.49) and 20 to 43 years (HR = 1.34; 95% CI, 1.15-1.57).

Results from co-sibling analyses found that risk associations were not related to shared genetic and environmental factors among families.

“Given the high prevalence of preterm birth (currently 10% in the U.S. and 5% to 8% in Europe) and more than 95% survival into adulthood, the associations we found with CKD have important public health implications,” Crump and colleagues wrote. “Our findings underscore the importance of public health strategies to prevent preterm birth, including better access to preconception and prenatal care for high risk women, and reduction of non-medically indicated deliveries before full term.” – by Erin Michael

Disclosures: Crump reports no relevant financial disclosures. Please see study for all other authors’ relevant financial disclosures.