Clinically recovered AKI linked to elevated pre-eclampsia risk
Women with a history of acute kidney injury (AKI) before pregnancy, despite apparent full recovery, are at greater risk of pregnancy complications such as pre-eclampsia, a study has found. This risk is modified by severity of the AKI episode.
Researchers examined the medical records of 14,486 women with singleton deliveries, among whom 246 had an episode of clinically recovered AKI (r-AKI) before conception. Women with r-AKI and controls had similar age (mean, 31 years) and body mass index (mean, 26.7 kg/m2) at first prenatal visit, although the former were more likely to have pre-existing diabetes mellitus (9 percent vs 5 percent; p=0.006).
In terms of pregnancy outcomes, the r-AKI had a higher rate of pre-eclampsia compared with non-r-AKI controls (22 percent vs 9 percent; p<0.001). Furthermore, infants of women in the r-AKI group were born earlier (gestational age, 38.2 vs 39.0 weeks; p<0.001) and were more likely to be small for gestational age (9 percent vs 5 percent; p=0.002).
The risk of pre-eclampsia increased with increasing severity of r-AKI. Specifically, the risk of the pregnancy complication was about threefold high in women who had had stage 2 AKI (adjusted odds ratio [OR], 3.5; 95 percent CI, 2.1–5.7) and about sixfold greater in those who had had stage 3 AKI (adjusted OR, 6.5; 3.5–12.0). This risk increase was not observed for stage 1 AKI (adjusted OR, 1.7; 0.9–3.2).
The present data indicate that reversible AKI is not harmless, researchers said. This has important implications for pregnancy counselling, underscoring the importance of active evaluation for episodes of AKI, as well as of AKI prevention, especially in young women.
Researchers postulated that women with clinically recovered AKI, especially those with severe AKI, have residual subclinical kidney disease and lower nephron mass prior to conceiving. Low nephron number and surrogates for low renal mass have been associated with adverse long-term health consequences, including hypertension and CKD, as well as gestational hypertension and pre-eclampsia. [J Am Soc Nephrol 2010;21:898-910; Am J Kidney Dis 2017;70:506-511]