Urinary biomarkers in neonates born to mothers with preeclampsia: A case-control study

Effects of preeclampsia (PE) on fetal renal development are unknown. We hypothesized that the circulating factors causing endothelial dysfunction and impaired renal function in mothers with PE adversely affect fetal kidneys.

To compare urinary biomarkers in infants born to mothers with and without PE.

Sixty-eight mothers and their newborns with gestational age ≥ 32 weeks were enrolled. We collected bag urine samples from infants during the first 48 h of life. Urine samples were centrifuged at 1500 rpm for 10 min. Supernatant after excluding the bottom 1 mL of urine was stored at -70 °C until assayed. Urinary creatinine, protein, cystatin C, nephrin, kidney injury molecule - 1, and klotho were measured.

Sixteen mothers in the PE group had severe features of PE. The PE group infants had lower body length compared to the control group (46.4 ± 3.4 vs 48.6 ± 3.4 cm; p = 0.007). Urine protein and creatinine were significantly higher in the PE group infants [protein 37.1 (14.4, 53.5) vs 20.3 (7.5, 30.0) mg/dl, p = 0.04; creatinine 63.4 (25.2, 96.6) vs 24.8 (19.8, 44.2) mg/dl, p = 0.008]. There were no statistically significant differences in the urinary concentrations of the remaining four biomarkers. The urinary protein, creatinine and nephrin concentrations had significant negative correlation with gestational age (p values 0.07, 0.0003 and 0.0008 respectively).

The findings of higher urinary protein and the observed trends in the levels of urinary nephrin and klotho are suggestive of glomerular immaturity and/or impaired function in infants born to mothers with PE.