Clinical Course and Considerations of a Stage G4 Chronic Kidney Disease Patient Who Successfully Initiated Dialysis During Pregnancy and Discontinued It Postpartum

Introduction

Chronic kidney disease (CKD) is recognized as a major risk factor for adverse pregnancy outcomes, including maternal mortality, preeclampsia, fetal growth restriction, preterm delivery, and fetal death. In normal pregnancy, the glomerular filtration rate increases by approximately 40–50%, resulting in physiologic hyperfiltration [1]. In CKD, the reduced nephron mass means that this pregnancy-related hyperfiltration further increases single-nephron workload (including intraglomerular pressure), which can promote proteinuria and accelerate loss of kidney function – the so-called hyperfiltration hypothesis [2].

In particular, pregnancies complicated by CKD stage G3 or higher are associated with substantial risks, often requiring dialysis initiation. Despite these risks, there are currently no established clinical guidelines or standardized criteria for initiating dialysis during pregnancy, nor are there well-defined parameters for fluid management in pregnant women with renal failure. In clinical practice, such decisions are often individualized, and there is a growing need for evidence-based strategies.

IgA nephropathy is the most common primary glomerular disease in Japan, typically affecting young adults and sometimes worsening during pregnancy. However, there are few reports describing cases in which a pregnant woman with IgA nephropathy and advanced CKD (stage G4) successfully continued pregnancy with dialysis and subsequently discontinued dialysis postpartum. Such cases provide valuable insights into clinical management and decision-making.

Given these challenges, preconception counseling is critically important for women with CKD, as it facilitates risk assessment and multidisciplinary care planning to reduce maternal and fetal complications. In cases like the present one, where pregnancy proceeds without prior evaluation, clinical management can become particularly complex.

Here, we present a case of a pregnant woman with CKD stage G4 who required dialysis during pregnancy and was able to discontinue dialysis postpartum. We highlight the practice of individualized fluid management using body composition analysis and discuss its potential contribution to both pregnancy continuation and successful dialysis withdrawal.

Case Report

The patient was a 41-year-old Japanese woman. At age 17, a renal biopsy was performed due to abnormal urine findings, and although the detailed histological findings were unclear, she was diagnosed with IgA nephropathy. Active treatment, such as steroid therapy, was not pursued, and the patient was monitored with antihypertensive therapy. However, she discontinued follow-up care after a few years. At age 30, she was found to have hypertension but did not seek medical attention. A spontaneous pregnancy was confirmed, and at 6 weeks and 0 days of pregnancy (December, Year X–1), she visited her previous physician and was found to have CKD stage G4 renal failure [with creatinine 148.5 μmol/L (40.7–69.9 μmol/L) and estimated glomerular filtration rate (eGFR) 28.2 mL/min/1.73 m2]. There was no history of infertility treatment, and testing for antiphospholipid syndrome had not been performed. She was referred to a nephrologist at the same institution. Urinalysis showed proteinuria, with a urinary protein-to-creatinine ratio, in grams of protein per grams of creatinine (g/gCr) of 1.9 g/gCr and microscopic hematuria with 5–9 red blood cells per high-power field. Despite being informed of the high maternal risk, including the potential need for dialysis, she expressed a strong desire to continue the pregnancy. At 20 weeks and 2 days (April, Year X), she was referred to our Perinatal and Maternal Medical Center as well as our department. On physical examination, there was no notable lower limb edema, and no other significant findings were observed. Methyldopa at a total daily dose of 1500 mg had been prescribed by her previous physician for the management of hypertension.

The initial examination findings are summarized in Table 1. The patient exhibited renal dysfunction consistent with stage G4 CKD, with a serum creatinine level of 139.7 μmol/L and an eGFR of 29.9 mL/min/1.73 m2. No deterioration in renal function was noted compared with the findings at the referring institution. Urinalysis revealed proteinuria, with a urinary protein-to-creatinine ratio of 0.36 g/gCr and microscopic hematuria (5–9 red blood cells per high-power field), indicating minimal urinary abnormalities. The low activity of glomerulonephritis suggested that the primary renal pathology was nephrosclerosis rather than active glomerular disease. As there were no signs of glomerulonephritis exacerbation or newly emerging renal disease, immunological testing was not performed. The pregnancy was managed with blood pressure control, salt restriction, and bed rest. During outpatient follow-up, blood pressure remained elevated, and antihypertensive therapy with methyldopa (1500 mg) and controlled-release nifedipine (20 mg) was continued. From 24 weeks and 1 day of gestation, low-dose aspirin (Bayaspirin 100 mg) was initiated for the prevention of preeclampsia. However, at 29 weeks and 2 days (June, Year X) of gestation, cervical shortening (25 mm) was observed, leading to a diagnosis of threatened preterm labor, and the patient was admitted to the hospital.

The clinical course is illustrated in Figure 1. Threatened preterm labor was managed conservatively with rest and observation, without tocolytic therapy. At the time of admission, the patient’s renal function had deteriorated, with a serum creatinine level of 159.1 μmol/L and an eGFR of 26 mL/min/1.73 m2. The patient’s proteinuria had increased to 1.3 g/gCr. Microscopic hematuria was noted at 10–19 red blood cells per high-power field, but the absence of a marked increase suggested no evidence of glomerulonephritis relapse. Renal function gradually declined before and after admission, and by 31 weeks and 3 days, her creatinine had risen to 189.2 μmol/L, eGFR had decreased to 21.5 mL/min/1.73 m2, and blood urea nitrogen (BUN) had increased to 13.2 mmol/L, all indicating a worsening trend. Blood pressure also showed an upward trend. Although termination of the pregnancy was considered, given the gestational age of 31 weeks and the potential long-term outcomes for the infant, including the possibility of extended neonatal intensive care unit (NICU) hospitalization and the associated burden on the child and family, the decision was made to prioritize the continuation of the pregnancy and initiate hemodialysis. The hemodialysis prescription is shown in Figure 2. Chest radiography showed no pulmonary congestion; oxygen saturation remained stable on room air, and there were no clinical signs of volume overload.

At one point, blood pressure became difficult to control, necessitating the continuous infusion of nicardipine. Although accurate urine measurement was sometimes challenging due to concurrent diarrhea, the patient reported no significant decrease in urine output. Maternal fluid status during dialysis was assessed based on blood pressure, physical examination findings, and measurements obtained using a bioelectrical impedance analysis (BIA; InBody Co., Ltd.) device prior to each dialysis session. Specifically, the ratio of extracellular water to total body water (ECW/TBW) was measured before every session as an objective marker of volume status. In addition, amniotic fluid volume was monitored using the amniotic fluid index (AFI).

At the time of dialysis initiation, the ECW/TBW ratio was 0.382. The ratio gradually increased over time and was maintained within the range of 0.403 to 0.419, with dialysis ultrafiltration volume adjusted accordingly. Although a decrease in AFI was observed during the course of treatment, it remained within the normal range (Figure 3). After initiation of a continuous intravenous infusion of nicardipine, blood pressure remained relatively well controlled in conjunction with volume management. After initiation of hemodialysis, we continued periodic fetal ultrasound examinations and conducted daily fetal heart rate monitoring (cardiotocography).

At 36 weeks and 0 days (July, Year X), after spontaneous rupture of membranes, labor ensued naturally, resulting in a vaginal delivery. During delivery, the patient experienced atonic postpartum hemorrhage with an estimated blood loss of 958 grams. After oxytocin (Atonin-O®) administration, uterine tone became adequate. As a result of renal ischemia, her renal function temporarily worsened, with serum creatinine increasing to 389.0 μmol/L and eGFR decreasing to 9.8 mL/min/1.73 m2, accompanied by a reduction in urine output.

After receiving a blood transfusion, renal function showed improvement. The final hemodialysis session was conducted on postpartum day 3, and by postpartum day 6, her serum creatinine had decreased to 187.4 μmol/L with an eGFR of 21.7 mL/min/1.73 m2. It was determined that dialysis could be discontinued and treatment was discontinued. The patient experienced no further renal deterioration, and with adjustments to her antihypertensive medications, both mother and baby were discharged on postpartum day 9. At the time of discharge, serum creatinine had improved to 171.5 μmol/L, and eGFR had increased to 23.9 mL/min/1.73 m2. Proteinuria, which had worsened to a peak of 8.31 g/gCr during hospitalization, decreased to 1.83 g/gCr following delivery. Hematuria remained in the range of 5–19 red blood cells per high-power field throughout the clinical course, without any marked exacerbation.

The newborn had a birth weight of 2111 g, with Apgar scores of 8 at 1 minute and 9 at 5 minutes. There were no abnormalities observed in the placenta or umbilical cord, and the amniotic fluid was normal in both appearance and quantity. After birth, the infant was admitted to the growing care unit. However, due to persistent hypoglycemia, the infant was transferred to the NICU, and remained there for 5 days. Phototherapy was administered for neonatal jaundice, and both mother and baby were discharged on day 9.

Discussion

CKD IN PREGNANCY:

Approximately 3% of women of reproductive age have CKD [3]. CKD is recognized as a major risk factor for adverse pregnancy outcomes, including maternal mortality, preeclampsia, fetal growth restriction, preterm delivery, and fetal death. A previous study reported that nearly half of women with moderate and severe renal insufficiency experience a decline in kidney function during pregnancy, and 23% of them progress to end-stage renal disease at 6 months postpartum [4].

ASSESSMENT AND MANAGEMENT OF RENAL DYSFUNCTION IN THIS CASE:

IgA nephropathy accounts for approximately a third of all renal biopsy diagnoses in Japan, with an annual incidence of 3.9 to 4.5 cases per 100 000 population. The peak onset occurs in women in their 20s to 30s, overlapping with the reproductive age group [3]

In IgA nephropathy, tissue damage is characterized by the proliferation of mesangial cells and expansion of the extracellular matrix, resulting in glomerular injury and sclerosis. In highly active cases, more severe tissue damage may occur and a semilunar body may form. In the chronic phase, fibrosclerosis and glomerulosclerosis predominate. As sclerotic glomeruli increase, normal glomeruli work compensatively, resulting in overfiltration, which is seen as hypertrophic glomeruli. In pregnancies complicated by IgA nephropathy, blood flow to the already overfiltered hypertrophic glomeruli increases, leading to further overfiltration, increased proteinuria, and worsening renal dysfunction. However, the cause of proteinuria is not limited to IgA nephropathy, and it is important to understand the cause and pathology, whether it is due to glomerulosclerosis or nephritis.

In CKD caused by systemic autoimmune diseases such as lupus nephritis, systemic inflammation is often present, and disease activity may require adjustments in immunosuppressive therapy. In contrast, IgA nephropathy is, in principle, a renal-limited disease, which constitutes a key difference in clinical management. However, the disease activity of IgA nephropathy can worsen during pregnancy.

Although the frequency of disease flare or renal function decline during pregnancy is considered lower in IgA nephropathy compared with systemic autoimmune diseases, the risk of deterioration increases in the presence of pre-existing renal impairment or significant proteinuria. When baseline eGFR is ≥60 mL/min/1.73 m2 and proteinuria is mild (<0.5 g/day), the incidence of irreversible renal function decline due to pregnancy is reported to be approximately 5–10% [4,5].

In contrast, in patients with more severe kidney disease (eg, eGFR <30 mL/min/1.73 m2 or proteinuria >1 g/day), the risk of accelerated renal function decline during or after pregnancy can reach 20–40% or higher [6]. In the present case, the patient was considered to be at high risk for pregnancy-related renal deterioration.

In the present case, the disease was judged to be low-active in terms of nephritis and the main pathology was sclerosing lesions. It was then determined that the glomerular overfiltration load needed to be reduced.

To reduce glomerular hyperfiltration, salt and protein restriction are considered important. However, excessive hypotension and excessive salt restriction are not recommended as they may reduce fetal-placental circulation [7]. On the other hand, hypertensive disorders of pregnancy are associated with decreased salt excretion and salt sensitivity [8,9], and moderate salt restriction is considered necessary in view of the complications of renal failure.

Protein restriction may reduce pregnancy-related glomerular hyperfiltration and functional stress on residual nephrons [10]. In the general pregnant population, increased protein intake is considered necessary [11]. However, the appropriate amount of protein intake for pregnant women with CKD has not been clearly established. In cases where pregnant women undergo long-term and frequent hemodialysis, a high-protein diet (1.5–1.8 g/kg/day) is recommended [12]. However, in the present case, dialysis was provided on a short-term and supplemental basis with the goal of dialysis withdrawal, and thus the above recommendation was considered not applicable. The appropriate protein intake should be determined based on multiple factors, including dialysis dose, residual renal function, maternal weight gain, and fetal growth.

In pregnancies complicated by nephritis, moderate salt- and protein-restricted management is considered to have an impact on the control of exacerbations of renal dysfunction. Therefore, treatment was continued by controlling blood pressure and limiting work prior to admission, and by limiting salt and protein on admission.

ASSESSMENT OF FLUID VOLUME:

In this case, fluid volume assessment for the mother included evaluating blood pressure and physical findings, along with the use of a BIA before each dialysis session to determine the ratio of ECW/TBW. Additionally, amniotic fluid volume was assessed by measuring the AFI. The AFI is calculated by dividing the maternal abdomen into 4 quadrants and summing the maximum depth of amniotic fluid pockets in each quadrant, measured in centimeters. An AFI of less than 5 cm is indicative of oligohydramnios, while an AFI of 25 cm or more suggests polyhydramnios.

The course of fluid volume assessment and dialysis fluid removal is shown in Figure 3. Although a decrease in AFI was observed, it remained within the normal range. The ECW/TBW ratio gradually increased, prompting adjustments to the fluid removal volume during dialysis. BIA is a non-invasive method that estimates body composition by measuring the body’s resistance to a weak alternating electrical current. Unlike radiographic techniques, which are generally avoided in pregnant women, BIA allows for quantitative assessment of body fluid status without the use of ionizing radiation.

The normal range for ECW/TBW is 0.36–0.40, with values above 0.40 indicating fluid overload. However, reference values for pregnant women have not been established. In hemodialysis patients, the risk of developing polyhydramnios increases due to excessive maternal blood volume [13]. BIA can assist in the determination of dry weight in dialysis patients and facilitate the early detection of both polyhydramnios and oligohydramnios. It is considered one of the few objective tools available for dynamically assessing maternal body fluid status throughout pregnancy. In this case, the fluid removal volume was determined by monitoring the ECW/TBW ratio along with urine output and physical findings.

FLUID MANAGEMENT STRATEGY IN HEMODIALYSIS WITH THE GOAL OF DIALYSIS WITHDRAWAL:

In this case, hemodialysis was initiated with the intention of eventual dialysis withdrawal. To prevent glomerular collapse, fluid management was maintained at a slightly elevated level. The AFI remained within the normal range, and there was no evidence of fetal growth restriction. Dialysis withdrawal was successfully achieved. In previously reported cases, hemodialysis was often continued for approximately 4 weeks postpartum; however, in the present case, dialysis withdrawal was achieved at an earlier stage [14]. These outcomes suggest that the fluid management strategy was effective, and that BIA may be a valuable tool for assessing fluid volume in similar cases.

COMPARISON BETWEEN PREGNANCY MANAGEMENT GUIDELINES FOR PATIENTS WITH KIDNEY DISEASE AND THIS CASE:

The 2017 guidelines for the management of pregnancy in patients with kidney disease cite 2 key studies, which are compared with the present case. Figure 4 illustrates that even in the early stages of CKD, various obstetric risks (such as the rate of cesarean section, preterm birth, birth weight, and NICU admission rates) are affected, and these risks increase as the stage of CKD progresses [15]. The present case was classified as CKD stage G4. Additionally, the table demonstrates that renal impairment increases the risks of conditions such as preeclampsia, fetal death, preterm birth, and NICU admission rates [16]. Even isolated proteinuria significantly increases these risks. Given that this case involved severe renal impairment, the outcome was relatively favorable, with a vaginal delivery at 36 weeks and 0 days, a birth weight of 2111 g, and only a few days of NICU management.

In patients with CKD at stages G3, G4, and G5, the risk of complications during pregnancy, such as premature birth and fetal growth restriction, is significantly elevated. This increased risk may lead to a deterioration of renal function, potentially necessitating the initiation of dialysis [17]. It is crucial to provide patients with a thorough explanation of these risks, although clear criteria for initiating dialysis during pregnancy have not been established. In maintenance hemodialysis patients, a pre-dialysis BUN level of less than 50 mg/dL is considered desirable [18], but there are no established criteria for initiating dialysis during pregnancy. There are reports suggesting a negative correlation between blood BUN levels and birth weight or gestational age [19]. In cases like this one, where the risk of preterm birth outweighs the risks associated with starting dialysis, early initiation of dialysis may be considered.

Given the potential for CKD to progress to a stage requiring maintenance dialysis and the specific concerns that may necessitate the early initiation of dialysis during pregnancy, it is essential to ensure that patients are fully informed [4]. This includes discussions about the possibility of transitioning to maintenance dialysis and the factors that may lead to the early initiation of dialysis during pregnancy. Providing comprehensive information and counseling helps patients make informed decisions about their health and pregnancy management from a CKD perspective, including consideration of permanent contraception (sterilization) when appropriate.

Conclusions

Pregnancies complicated by renal failure are associated with an increased risk of various pregnancy complications. In pregnancies complicated by IgA nephropathy, it is important not only to pay attention to renal function such as eGFR, but also to determine the stage of nephritis (active nephritis or nephrosclerosis), since there is no uniform cause of proteinuria. In this case, in which glomerular collapse was presumed to be the primary pathology, the decision regarding in-hospital management was based on renal function, proteinuria, and gestational age.

Strict salt restriction was implemented to prevent the worsening of proteinuria and renal dysfunction. Additionally, fluid control through dialysis may have contributed to the patient’s withdrawal from dialysis postpartum. Moreover, dialysis therapy may have contributed to a reduction in obstetric complications.