Abstract
Background and Aims
Pregnancy in patients with chronic glomerulonephritis (CGN) is associated with higher risk of complications and unfavorable outcomes compared to the general population. The aim of the study was to determine the incidence of pregnancy complications and outcomes in patients with preexisting CGN.
Method
126 pregnancies in 119 women with CGN and CKD 1-4 stages: 1 st. – 86 patients, 2 st. – 17, 3 st. – 20, 4 st. – 3 and 20 pregnancies in 20 age-matching healthy women were included. Patients with secondary CGN, multiple pregnancy, pregnancy after IVF were excluded. A kidney biopsy was performed in 18 of 119 (15.1%) women: 15 – before conception and 3 – after delivery. IgA-nephropathy was detected in 11 of 18 (61.1%) patients, MCD/FSGS – in 4 (22.2%), MPGN – in 3 (16.7%). The incidence of unfavorable pregnancy outcome, preeclampsia (PE), preterm delivery, cesarean section (CS), low birth weight (LBW < 2500 g), small for gestational age (SGA) newborn (birth weight < 10th percentile), mean term of delivery, mean birth weight, frequency of treatment in neonatal intensive care unit (NICU) and achieving of end-stage kidney disease in mothers after delivery were evaluated.
Results
CKD was first diagnosed during pregnancy in 34.1% women with CGN. The incidence of adverse pregnancy outcomes, preterm delivery, LBW, SGA, and treatment in the NICU did not differ between groups, while the frequency of PE and CS were higher, and mean gestational age at delivery, birth weight were lower in the CGN group compared to the healthy control (Table).
Severe PE was observed in 6 of 32 (18.7%) patients with PE and CGN. The incidence of PE increased in advanced stages of CKD, but the differences were not significant: 19.8% - in CKD1, 35.3% - CKD2, 35% - CKD3, 66.7% - CKD4, p=0.112. The frequency of PE depended on the presence of baseline nephrotic-range proteinuria (NPU) and chronic arterial hypertension (AH): PE was observed in women w/o NPU and w/o AH in 8.3% cases, w/o NPU and with AH – in 39%, with NPU and w/o AH – in 44,4%, with NPU and with AH – in 43.8%, p=0.00048.
Preterm delivery, CS and LBW were more common in women with chronic renal failure, and their frequency increased with increasing severity of CKD: CKD1 – 3.5%, 21.2%, 3.5% resp.; CKD2 – 6.7%, 53.3%, 20%; CKD3 – 40%, 70%, 40%; CKD4 – 100%, 100%, 100% (p<0.0001, for all characteristics). We found differences in gestational age at delivery depending on the stages of CKD: in CKD1 it was 38.9 ± 1.3 wks, CKD2 – 38.2 ± 2.1 wks, CKD3 – 36.3 ± 3.5 wks, CKD4 – 32.4 wks (one child), p=0.00013. The proportion of newborns requiring intensive care was higher in mothers with CKD3 (30%) and CKD4 (100%) compared with CKD1 (0%) and CKD2 (13.3%), p<0.0001.
Five of 126 (4%) patients in CGN group achieved stage 5 CKD with average postpartum follow-up period of 92.6 ± 20.5 months; 4 women had CKD3 during pregnancy, one – CKD1. Now 2 patients are treated with regular hemodialysis, 3 - live with kidney transplant.
Conclusion
Chronic glomerulonephritis has a negative effect on pregnancy course, increasing the incidence of PE and CS and contributing to reduce gestational age and birth weight. Incidence of preterm delivery, CS, LBW and proportion of newborns treated in NICU were highest in patients with CKD 3-4.
Estimating outcomes in newborn infants using fuzzy logic