Premature birth is linked to increased risk of chronic kidney disease into later lifeBMJ 2019; 365 doi: https://doi.org/10.1136/bmj.l1986 (Published 02 May 2019) Cite this as: BMJ 2019;365:l1986
Babies born at less than 37 weeks have a nearly twofold increased risk of developing chronic kidney disease (CKD) from childhood into mid-adulthood, a new study suggests.1
The paper, published in The BMJ, found preterm and early term birth are strong risk factors for the development of CKD, with a threefold increased risk for those born at less than 28 weeks, and a small increased risk in those born before their due date but after 37 weeks.
Researchers said that the high levels of preterm birth (currently 10% in the US and 5-8% in Europe) may be creating a “silent epidemic” of CKD, and highlighted the need for long term monitoring of those affected.
Preterm birth (before 37 weeks of pregnancy) interrupts kidney development and maturity during late stage pregnancy, resulting in the formation of fewer nephrons. A lower number of nephrons has been associated with the development of high blood pressure and progressive kidney disease later in life.
Since the long term risks for adults who were born prematurely are unclear, however, the research team set out to investigate the relationship between preterm birth and risk of CKD from childhood into mid-adulthood.
They analysed data for over four million single live births in Sweden between 1973 and 2014, with cases of CKD identified from nationwide hospital and clinic records.
The researchers found that overall 4305 (0.1%) of participants had a diagnosis of CKD during 87 million person years of follow-up, yielding an overall incidence rate of 4.95 per 100 000 person years across all ages (0-43 years).
Preterm birth was associated with a nearly twofold increased risk of CKD into mid-adulthood (9.24 per 100 000 person years), while extremely preterm birth (less than 28 weeks) was associated with a threefold increased risk of CKD into mid-adulthood (13.33 per 100 000 person years).
Meanwhile a slightly increased risk (5.9 per 100 000 person years) was seen even among those born at early term (37-38 weeks).
The association between preterm birth and CKD was strongest up to 9 years of age, then weakened but remained increased at ages 10-19 years and 20-43 years, the paper said.
Study author Casey Crump, from the Icahn School of Medicine at Mount Sinai, said: “This research is important because preterm birth is common (11% of all births worldwide) and may already be contributing to a ‘silent epidemic’ of chronic kidney disease.
“Our findings show that people born prematurely need long term monitoring to help preserve their kidney function across the life course.”