Clinical and Paraclinical Features in Pregnancies Associated With Renal Impairment Due to Hypertensive Complications.

Abstract

Background An association between renal impairment and hypertensive complications occurring during pregnancy has been shown in a limited number of studies. As a consequence of a lack of clear criteria for diagnostic certainty, acute renal failure during pregnancy is a challenging pathology to diagnose, mainly due to the physiological reduction of nitrogen retention parameters. In light of the fact that renal injury is associated with a poor maternal and fetal prognosis, this study aims to determine the maternal demographic features and the cut-off of serum creatinine that can lead to a heightened risk of prematurity, stillbirth, intrauterine growth restriction, or the necessity of neonatal intensive care. Methods We performed a study that included a cohort of 45 pregnant women with acute renal injury who delivered in the Department of Obstetrics and Gynecology of the University Emergency Hospital in Bucharest between January 1, 2017, and December 31, 2022, a cohort of 45 pregnant women with a value of serum creatinine between 0.8 and 1 mg/dL, and a cohort of 45 pregnant women, selected at random, with a value of serum creatinine under 0.8 mg/dL, who delivered in the same period in the aforementioned unit. The analysis included neonatal outcomes (preterm birth, intrauterine growth restriction, stillbirth, Apgar score calculated at one minute, the need for neonatal intensive care), maternal demographic features, medical and obstetrical history, and paraclinical parameters. Results The incidence of acute renal injury was 0.33% for the entire cohort of patients who gave birth in our hospital. Out of that lot, 65.21% of the cases of acute renal impairment associated with pregnancy were caused by hypertensive complications. The mean age of patients with acute kidney injury (AKI) was 29.4 ± 6.66, preponderantly primiparous. The majority of the neonates from patients with AKI (62.22%) were born with a birth weight under 2.500 grams. Preterm deliveries were preponderant (66.66%) in patients with AKI, while in the control group, the incidence of preterm deliveries was 48.88%. Stillbirth in the AKI group had an incidence of 13.33%, while in the control group, there were none. Due to these neonatal complications, most of the newborns in the AKI group needed neonatal intensive care. An important percentage of the patients who developed AKI (40%) did not benefit from proper medical care during pregnancy or before admission to our unit. The cutoff of 1.09 mg/dL of serum creatinine level was established following receiver operating characteristic curve analysis. Conclusion AKI during pregnancy is associated with hypertensive disorders, low birth weight, and preterm deliveries.