Changes In Serum Creatinine Values During And After Pregnancy In A Cohort Of Women With Or Without Pre-existing Chronic Kidney Disease
Background: Chronic kidney disease (CKD) occurs in up to 3.3% of women of childbearing age. Impaired kidneys may not sufficiently adapt to physiological changes during pregnancy that may result in accelerated CKD progression.
Objective: To describe changes in renal filtration during and after pregnancy in women with or without CKD.
Methods: We performed a longitudinal descriptive study using data from the UK-based Clinical Practice Research Datalink (2000-2018). We included pregnancies ending in live birth if they had ≥ 1 serum creatinine (SCr) value during a 1-year baseline period before the estimated last menstrual period or during trimester 1. Pregnancies were categorized into 3 groups based on the mean estimated glomerular filtration rate (eGFR [ml/min/1.73m2], CKD-EPI formula) during baseline/trimester 1: no CKD (eGFR ≥ 90), mild CKD (eGFR = 60-90), moderate-severe CKD (GFR < 60).
We captured demographics and risk factors for CKD and calculated percentage changes of mean SCr levels (group means) as a proxy for renal filtration in 3-month intervals during and until 1 year after pregnancy. We quantified the difference between the mean baseline eGFR and the mean eGFR 6-12 months after delivery.
Results: Of 169’855 included pregnancies, maternal moderate-severe CKD was present in 981 (0.6%), mild CKD in 29’433 (17.3%), and no CKD in 139’441 (82.1%) pregnancies. Pre-existing hypertension, diabetes, and/or obesity was recorded in 37% in moderate-severe CKD, and in 30% in the other 2 groups. Autoimmune diseases pre-existed in 3-4% in all groups. Mean reduction in SCr levels were larger between baseline and the end of trimester 2 in women without CKD (-22%) and with mild CKD (-24%) than in women with moderate-severe CKD (-14%). Thereafter, mean SCr levels increased, to level off around 6 months after delivery. In women without CKD, mean eGFR levels 6-12 month after delivery (118 ml/min, SD 15) were comparable to baseline SCr levels (119 ml/min, SD 13). Women with mild CKD revealed an increased eGFR (97 ml/min, SD 18) after delivery (baseline eGFR 88 ml/min, SD 9). In women with moderate-severe CKD, the post-pregnancy eGFR (55 ml/min, SD 23) was similar as in baseline (50 ml/min, SD 14), but sample size was small due to incomplete lab data.
Conclusions: Our results suggest that kidneys of women with moderate-severe CKD adapted to a lesser degree to physiological changes during pregnancy, but sample size was small. Renal filtration was not decreased within 1 year after delivery in all groups. The increased post-pregnancy eGFR in women with mild CKD may reflect continued hyperfiltration or random variability.
Future projects:
Prevalence of Chronic Kidney Disease in Women of Childbearing Age
Effect of Pregnancy on Chronic Kidney Disease Progression after Pregnancy |
