Women who are overweight and have donated a kidney may be at a greater risk for preeclampsia during pregnancy, according to a recently published study.

The increased risk comes about because of the additional strain placed on the remaining kidney during the pregnancy, according to Marco van Londen, MD, and colleagues in the division of nephrology at University Medical Center Groningen and University of Groningen in the Netherlands. Their study was published ahead of print in the American Journal of Physiology—Renal Physiology.

When a person donates a kidney, the blood vessels in the remaining kidney widen substantially. This allows the kidney to filter more blood and perform the work of two kidneys. However, this widening of the vessels also causes a reduction in renal function reserve, which is the ability of the kidney to adapt to changes in physiological demands, the researchers wrote.

van Londen and colleagues studied 105 women who were kidney donors and of childbearing age. They found that compared with kidney donors who had a BMI in the normal range (less than 25 kg/m2), kidney donors who were overweight had lower renal function reserve. This diminished ability during pregnancy for the kidney to adapt to the body’s changing needs placed women at increased risk for preeclampsia, they concluded.

“Prospective studies should explore whether BMI reduction prior to conception is of benefit to overweight female kidney donors during and after pregnancy,” the researchers wrote. – by Mark E. Neumann

van Londen M, et al. Am J Physiol Renal Physiol.2018;doi:10.1152/ajprenal.00492.2017.

Disclosures: The authors had no relevant financial disclosures.