Kidney Disease and Maternal and Fetal Outcomes in Pregnancy

Abstract

Background Pregnancy in kidney disease is considered high risk but the degree of this risk is unclear. We tested the hypothesis that kidney disease in pregnancy is associated with adverse maternal and fetal outcomes. Study Design Retrospective study comparing pregnant women with and without kidney disease. Setting & Participants Using data from an integrated healthcare delivery system from 2000 through 2013, 778 women met the criteria for kidney disease. Using a pool of 74,105 women without kidney disease, we selected 778 women to use for matches for the women with kidney disease. These women were matched 1:1 by age, race, and history of diabetes, chronic hypertension, liver disease and connective tissue disease. Predictor Kidney disease was defined using the NKF-KDOQI definition for chronic kidney disease or ICD-9 codes prior to pregnancy or serum creatinine >1.2 mg/dL and/or proteinuria in first trimester. Outcomes & Measurements Maternal outcomes included preterm delivery, delivery via cesarean section, preeclampsia/eclampsia, length of stay at hospital (>3 days) and maternal death. Fetal outcomes included low birth weight (weight <2500 g), small for gestational age, number of admissions to neonatal intensive care unit (NICU) and infant death. Results Compared to women without kidney disease, those with kidney disease had 52% increased odds of preterm delivery (OR, 1.52; 95% CI, 1.16-1.99) and 33% increased odds of delivery via cesarean section (OR, 1.33; 95% CI, 1.06-1.66). Infants born to women with kidney disease had 71% increased odds of admission to NICU or infant death compared to infants born to women without kidney disease (OR, 1.71; 95% CI, 1.17-2.51). Kidney disease was also associated with two-fold increased odds of low birth weight (OR, 2.38; 95% CI, 1.64-3.44). Kidney disease was not associated with increased risk of maternal death. Limitations Data on level of kidney function and cause of death not available. Conclusions Kidney disease in pregnancy is independently associated with adverse maternal and fetal outcomes when other comorbid conditions are controlled by matching.

The Spectrum of Adverse Pregnancy Outcomes Based on Kidney Disease Diagnoses: A 20-Year Population Study

“…Our study found a strong association between maternal kidney conditions and adverse fetal outcomes including preterm birth, low birth weight, and NICU admission consistent with previous studies in women with kidney diseases [2,5,10,23,24,26]; however, the risk of a smallfor-gestational age infant was not observed to be increased, indicating low birth weight was a function of preterm birth rather than growth restriction. Previous studies have identified a similar lack of association between a kidney disease and the delivery of SGA infants [5], which was postulated to reflect institutional policy toward early delivery where signs of growth restriction were evident [2].…”

“…This may reflect expedited delivery for fetal or maternal medical reasons. All women except those with pyelonephritis had an increased risk of requiring Caesarean section, consistent with existing literature for pregnancies with kidney disease [2,10,26]. This association was attenuated and not significant after adjustment for BMI (2007 model), which has a known association with Caesarean section rates [27].…”

“…The increased risk of preeclampsia among women with kidney disorders was consistent with but of lesser magnitude than a previous meta-analysis, which demonstrated that women with CKD experienced 10 times the odds of preeclampsia [24]. Of note, some studies including the HUNT II study, and a American matched cohort study of 778 women both recently failed to demonstrate an association between CKD and preeclampsia [5,10]. An association between prior history of kidney stones [13] or acute kidney injury that recovers [25] and pregnancy hypertension has also been described, suggesting there may be common maternal factors predisposing to kidney disorders and responses in pregnancy.…”

“…Outcomes for Australian women who had pregnancies while receiving dialysis or after transplantation have previously been explored [7][8][9]. Less is known about the prevalence and impact of earlier stages of chronic kidney impairment [2,10] and transient pathologies such as pyelonephritis and urological disorders [11][12][13]. Our knowledge is also hampered by the lack of routine kidney function testing in pregnancy.…”

World kidney day 2018; chronic kidney disease and women, the long way we have come

“…There is still a considerable risk for pregnancy complications, especially in women with more severe forms of CKD. Additionally, true risks for poor obstetric outcomes cannot be predicted accurately (10). We have come a long way, however, we are far from the end of the road.…”