Pregnancy in Inherited Hypokalemic Salt-Losing Renal Tubular Disorder

Primary aldosteronism in pregnancy

Primary aldosteronism (PA) is the most common form of secondary hypertension. Although hypertensive disorders seem to affect around 5-10% of pregnancies worldwide, literature counts less than 80 cases of PA diagnosed during the peri-partum period. In this review we discuss about current knowledge on pathophysiology, natural history, diagnosis and treatment of PA in pregnancy. Because of the physiologic changes in the renin-angiotensin-aldosterone system (RAAS) and the contraindication to both confirmatory test and subtype differentiation, diagnosis of PA during pregnancy is challenging and relies mostly on detection of low/suppressed renin and high aldosterone levels. The course of pregnancy in patients with PA is highly variable, ranging from progesterone-induced amelioration of blood pressure (BP) control to severe and resistant hypertension with potential maternal and fetal complications. Mineralcorticoid receptor antagonists (MRA) are the recommended and most effective drugs for treatment of PA. As the anti-androgenic effect of spironolactone can potentially interfere with sexual development, their prescription is not recommended during pregnancy. On the other side, eplerenone, has proven to be safe and effective in 6 pregnant women and may be added to conventional first line drug regimen in presence of resistant hypertension or persistent hypokalemia. Ideally, patients with unilateral forms of PA should undergo adrenalectomy prior to conception, however, when PA is diagnosed during pregnancy and medical therapy fails to adequately control hypertension or its complications, adrenalectomy can be considered during the second trimester in case of unilateral adrenal mass at MRI-scan.

Gitelman syndrome diagnosed in the first trimester of pregnancy: a case report and literature review

Objectives

Gitelman syndrome is a rare salt-losing tubulopathy caused by inactivating mutations in the SLC12A3 gene, which is expressed in the distal convoluted tubule and accounts for 5–10% of renal sodium reabsorption. Atypical symptoms and insidious conditions generally delay diagnosis until childhood or even adulthood. Here, we report the case of a 22-year-old Chinese woman who was admitted to our endocrinology department for severe hypokalemia during pregnancy.

Case presentation

The patient had no specific symptoms but exhibited hypokalemia, metabolic alkalosis, hypomagnesemia, hypocalciuria, hyperreninemia, hyperaldosteronism, and normal blood pressure. Together, these symptoms indicated the clinical diagnosis of Gitelman syndrome, which was confirmed by genetic analysis. Many drugs have limited safety data during early pregnancy, and optimum potassium and magnesium levels are necessary for a successful pregnancy.

Conclusions

Diagnosis and management of Gitelman syndrome are crucial during pregnancy to ensure the safety of the mother and fetus, especially during the first trimester.

Peripartum Management of Gitelman Syndrome for Vaginal Delivery: A Case Report and Review of Literature

We describe the anesthetic management of a spontaneous vaginal delivery at 38 weeks' gestation in a 36-year-old patient with Gitelman syndrome (GS). GS is a rare autosomal recessive renal tubulopathy characterized by hypomagnesemia, hypocalciuria, and secondary aldosteronism, which results in hypokalemia and metabolic alkalosis. To minimize any increase in catecholamine levels and consequent risk of ventricular arrhythmias, a labor epidural analgesia was administered using ropivacaine and fentanyl, along with intravenous magnesium and potassium supplementation. Ropivacaine was substituted for routine bupivacaine to decrease the risk of drug-induced cardiotoxicity. In the event of a cesarean section, the anesthetic plan was to continue with top-up epidural anesthesia and in case of failure, to convert to general anesthesia using propofol and rocuronium for induction. Delivery outcome was successful and uneventful.

Clinical and laboratory features of female Gitelman syndrome and the pregnancy outcomes in a Chinese cohort

AIM

Gitelman syndrome (GS) is a rare inherited salt-losing renal tubulopathy. Data on clinical features and the pregnancy outcome for female GS patients in a large cohort are lacking. The study was aimed to explore the phenotype and pregnant issue for female GS patients.

METHODS

GS cases from the National Rare Diseases Registry System of China (NRSC) were collected, and detailed clinical, laboratory and genetic data were analysed. Articles on pregnancy in GS were also systemically reviewed.

RESULTS

A total of 101 GS patients were included; among them, 42.6% were female and 79.2% showed hypomagnesaemia. A lower proportion of female patients presented before 18 years of age, with less frequently reported polyuria, higher serum potassium and less urine sodium and chloride excretions. There was no gender difference in the sodium-chloride cotransporter (NCC) dysfunction evaluated by hydrochlorothiazide test. Twelve of the 43 female GS patients delivered after disease symptom onset, and their pregnancies were generally uneventful. As a group, pregnant GS patients had lower potassium levels in the first-trimester (P = .002) requiring higher potassium supplementation. After delivery, serum potassium (P = .02) and magnesium (P = .03) increased significantly. Both caesarean section and vaginal delivery were safe.

CONCLUSION

Female GS patients may have a less severe phenotype with generally favourable outcomes of pregnancy. Intensive monitoring and increased potassium supplementation are necessary during pregnancy, especially in the first-trimester.

Anaesthesia for emergency caesarean section in a patient with Gitelman syndrome

Gitelman syndrome is a rare autosomal recessive salt-losing disorder of renal tubules, which results in hypokalemic metabolic alkalosis. Associated hypomagnesaemia and hypocalcaemia are also seen. Gitelman syndrome is a variant of renal Bartter's syndrome. Anaesthetic management of these obstetric patients is challenging and requires a careful multidisciplinary approach. Close monitoring of potassium and magnesium levels and their supplementation is required to avoid complications to mother and baby.

Gitelman Syndrome Diagnosed in a Woman in the Second Trimester of Pregnancy

Gitelman syndrome is a rare renal tubule disease characterized by hypokalaemia, metabolic alkalosis, hypomagnesaemia, hypocalciuria and normal blood pressure. It shows autosomal recessive inheritance and is usually not diagnosed until late childhood or adulthood. We report the case of 34-year-old woman who at 21 weeks of pregnancy was admitted to the gynaecology department for abdominal pain, muscle cramps and weakness. Routine blood tests showed hypokalaemia (2.32 mEq/l), hypomagnesaemia (1.18 mEq/l), compensated metabolic alkalosis (pH 7.439, bicarbonate 26.1 mmol/l), increased urinary magnesium excretion (140.25 mg/day, normal range 73–122 mg/day) and reduced urinary calcium excretion (49.25 mg/day, normal range 100–250 mg/day). In light of these findings, the patient was diagnosed with Gitelman syndrome and optimum potassium and magnesium levels were maintained with oral supplements.

Renal physiology and fluid and electrolyte disorders in pregnancy

The majority of women are healthy entering pregnancy and do not require measurement of renal function or serum electrolytes. Clinicians must remain alert to the possibility of renal as well as fluid and electrolyte disorders in pregnancy, as the presenting complaints are often vague and mistaken for the normal physiology of pregnancy. In this chapter, our objectives are 1) to review the renal physiology from a practical/clinical standpoint; 2) to provide the clinical obstetrician a case-based approach to fluid and electrolyte disorders commonly encountered in pregnancy; 3) to consolidate knowledge on renal physiology and fluid and electrolyte disorders in pregnancy with MCQs that are directly aligned with content; and 4) to highlight key practice points and present a research agenda.

[Management of Gitelman syndrome during pregnancy reporting 12 cases]

INTRODUCTION

Gitelman syndrome is a rare hereditary renal tubulopathy, responsable of hypokalemia and hypomagnesaemia-related ionic disorders, which management is poorly codified during pregnancy. We report 12 cases of pregnancies with Gitelman syndrome and we compare our data with those of literature.

MATERIAL AND METHODS

It is a report of 12 pregnancies in 5 patients with Gitelman syndrome between 2002 and 2016. Follow up and outcome of pregnancy, delivery modalities and maternal-fetal prognosis have been collected.

RESULTS

In our serie, maximum kaliemie observed was 3.4mmol/L, with an average potassium, over all pregnancies of 2.3mmol/L. Oral potassium and magnesium supplementation at the end of pregnancy were 8900mg/day and 460mg/day, respectively. There were no serious maternal complications. Two pregnancies were complicated by intrauterine growth retardation in a context of preeclampsia. There is a large disparity in the methods of anesthetic management of these patients. Materno-fetal prognosis at 1 month post-partum is good.

CONCLUSION

Gitelman syndrome is a rare pathology where there is a lack of homogeneity in management of pregnancy. Monitoring of monthly ionogram is necessary. The goal is to obtain stable, non-symptomatic kaliemias, which will never be standardized even in increasing treatment. The most important is to inform and detect situations at risk of decompensation, including vomiting or the use of certain anesthetics. In agreement with literature data, monitoring of fetal growth and the amount of amniotic fluid in the third trimester is still warranted. These pregnancies require the development of a common care in multidisciplinary consultation meeting.

Hereditary Renal Diseases

Hereditary kidney disease comprises approximately 10% of adults and nearly all children who require renal replacement therapy. Technologic advances have improved our ability to perform genetic diagnosis and enhanced our understanding of renal and syndromic diseases. In this article, we review the genetics of renal diseases, including common monogenic diseases such as polycystic kidney disease, Alport syndrome, and Fabry disease, as well as complex disorders such as congenital anomalies of the kidney and urinary tract. We provide the nephrologist with a general strategy to approach hereditary disorders, which includes a discussion of commonly used genetic tests, a guide to genetic counseling, and reproductive options such as prenatal diagnosis or pre-implantation genetic diagnosis for at-risk couples. Finally, we review pregnancy outcomes in certain renal diseases.

Two cases of successful pregnancy in patients with Gitelman's syndrome

Gitelman's syndrome (GS) is a distal convoluted tubule (DCT) defect clinically characterized by hypokalemic metabolic alkalosis. Pregnancy in women with GS often results in severe hypomagnesemia and hypokalemia. We report two cases of successful pregnancies, after previous fetal loss, in patients with GS managed with aggressive oral and intravenous electrolyte repletion. These cases illustrate increased potassium and magnesium requirements over the course of the pregnancies and are notable due to the high doses of electrolytes required. They also demonstrate the possibility of successful pregnancy outcomes with frequent laboratory monitoring and aggressive titration of electrolyte replacement either orally or intravenously to maintain appropriate serum levels necessary to provide a suitable environment for fetal development.

Gitelman syndrome: consensus and guidance from a Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference

Gitelman syndrome (GS) is a rare, salt-losing tubulopathy characterized by hypokalemic metabolic alkalosis with hypomagnesemia and hypocalciuria. The disease is recessively inherited, caused by inactivating mutations in the SLC12A3 gene that encodes the thiazide-sensitive sodium-chloride cotransporter (NCC). GS is usually detected during adolescence or adulthood, either fortuitously or in association with mild or nonspecific symptoms or both. The disease is characterized by high phenotypic variability and a significant reduction in the quality of life, and it may be associated with severe manifestations. GS is usually managed by a liberal salt intake together with oral magnesium and potassium supplements. A general problem in rare diseases is the lack of high quality evidence to inform diagnosis, prognosis, and management. We report here on the current state of knowledge related to the diagnostic evaluation, follow-up, management, and treatment of GS; identify knowledge gaps; and propose a research agenda to substantiate a number of issues related to GS. This expert consensus statement aims to establish an initial framework to enable clinical auditing and thus improve quality control of care.

Gitelman syndrome: a rare life-threatening case of hypokalemic paralysis mimicking Guillain-Barré syndrome during pregnancy and review of the literature

In rare cases, patients with Gitelman syndrome may present with hypokalemic paralysis mimicking Guillain–Barré syndrome. The severity of resultant symptoms may be life‐threatening. Controversial drugs such as aldactone, amiloride, and eplerenone should be used in this situation despite the lack of safety data.

Primary aldosteronism and pregnancy

Primary aldosteronism is the most common cause of secondary hypertension. Less than 50 cases of pregnancy in women with primary aldosteronism have been reported, suggesting the disorder is significantly underdiagnosed in confinement. Accurate diagnosis is complicated by physiological changes in the renin-angiotensin-aldosterone axis in pregnancy, leading to a risk of false negative results on screening tests. The course of primary aldosteronism during pregnancy is highly variable, although overall it is associated with a very high risk of fetal and maternal morbidity and mortality. The optimal management of primary aldosteronism during pregnancy is unclear, with uncertainty regarding the safety of mineralocorticoid antagonists and amiloride, their relative efficacy compared with the antihypertensive medications commonly used during pregnancy, and as to whether prognosis is improved by laparoscopic adrenalectomy where an adrenal adenoma can be demonstrated.

Renal NCC is unchanged in the midpregnant rat and decreased in the late pregnant rat despite avid renal Na+ retention

Pregnancy is characterized by plasma volume expansion due to Na(+) retention, driven by aldosterone. The aldosterone-responsive epithelial Na(+) channel is activated in the kidney in pregnancy. In the present study, we investigated the aldosterone-responsive Na(+)-Cl(-) cotransporter (NCC) in mid- and late pregnant rats compared with virgin rats. We determined the abundance of total NCC, phosphorylated NCC (pNCC; pT53, pS71 and pS89), phosphorylated STE20/SPS-1-related proline-alanine-rich protein kinase (pSPAK; pS373), and phosphorylated oxidative stress-related kinase (pOSR1; pS325) in the kidney cortex. We also measured mRNA expression of NCC and members of the SPAK/NCC regulatory kinase network, serum and glucocorticoid-regulated kinase (SGK)1, total with no lysine kinase (WNK)1, WNK3, and WNK4. Additionally, we performed immunohistochemistry for NCC kidneys from virgin and pregnant rats. Total NCC, pNCC, and pSPAK/OSR1 abundance were unchanged in midpregnant versus virgin rats. In late pregnant versus virgin rats, total NCC and pNCC were decreased; however, pSPAK/OSR1 was unchanged. We detected no differences in mRNA expression of NCC, SGK1, total WNK1, WNK3, and WNK4. By immunohistochemistry, NCC was mainly localized to the apical region in virgin rats, and density in the apical region was reduced in late pregnancy. Therefore, despite high circulating aldosterone levels in pregnancy, the aldosterone-responsive transporter NCC is not increased in total or activated (phosphorylated) abundance or in apical localization in midpregnant rats, and all are reduced in late pregnancy. This contrasts to the mineralocorticoid-mediated activation of the epithelial Na(+) channel, which we have previously reported. Why and how NCC escapes aldosterone activation in pregnancy is not clear but may relate to regional differences in aldosterone sensitivity the increased K(+) intake or other undefined mechanisms.

Gitelman syndrome during pregnancy – from diagnosis to treatment: a case series and review of the literature

Objective: Gitelman syndrome (GS) is a rare renal disease, originating from a defect in the Na-Cl co-transporter in the distal tubule, which causes hypokalemia, hypomagnesemia, hypocalciuria, metabolic alkalosis and low-normal blood pressure. Mild hypokalemia of pregnancy is physiological. Fatigue, nausea, vomiting, polyuria and low blood pressures are also common complaints associated with a normal pregnancy. Therefore, the diagnosis of an organic renal disorder, i.e., GS, may go undetected, until severe hypokalemia and possible life-threatening cardiac arrhythmias develop. Maternal consequences are obvious. The possibility of fetal pathology remains unclear.

Study design: In this study, we describe nine pregnancies in seven women with a clinical diagnosis of GS. Nearly all women were diagnosed initially during pregnancy. We describe their clinical presentation, serum and urine electrolyte levels during pregnancy and immediately post-partum, their treatment and pregnancy outcome.

Results: Fetal pregnancy outcomes were mostly favorable. While it is likely that women suffering from GS do not require special fetal surveillance, they are at high risk for electrolyte depletion and thus aggravation of GS during pregnancy.

Conclusion: Clinical suspicion of GS should arise in all women presenting with symptomatic hypokalemia. Once the diagnosis is made, adequate supplementation and routine maternal monitoring should ensue.

Unexpected clinical sequelae of Gitelman syndrome: hypertension in adulthood is common and females have higher potassium requirements

Background

Gitelman syndrome (GS) is a rare inherited disorder caused by mutations in SLC12A3, encoding the thiazide-sensitive transporter NCCT (sodium chloride co-transporter) in the distal tubule. It is characterized by renal potassium (K) and magnesium (Mg) wasting, relative hypotension and hypocalciuria. However, there is phenotypic variability and long-term studies are scarce.

Methods

We retrospectively assessed clinical and genetic characteristics, and electrolyte requirements, in a cohort of 36 patients with genetically proven GS.

Results

The 21 males and 15 females were of median age 39.5 years, range 17–66 years. Six were diagnosed in childhood. Among the 72 mutant alleles, 41 different sequence alterations were identified, of which 13 were previously unreported. Surprisingly, 44% (n = 16) of the cohort has developed hypertension (13 males, 3 females, P = 0.019; median age 53 versus 57 years, P = 0.95). One was already hypertensive by age 23 years. Currently normotensive patients were significantly younger: median 37 versus 55 years (P = 0.005). Hypertensive patients were more likely to harbour mutations in the C-terminal half of the NCCT protein (P = 0.016). Females required more K (median 128 versus 72 mmol/day; P = 0.01) but not Mg. Those with exon 26 and/or at least one destructive mutation had higher K requirements than those with neither: 108 versus 72 mmol (P = 0.016) and a tendency towards higher Mg needs: 30 versus 7.4 mmol (P = 0.07).

Conclusions

Our findings suggest that the development of secondary hypertension may be an expected feature of the ageing GS population despite the obligate salt wasting that characterizes the disorder. We hypothesize that this may be related to chronic secondary hyperaldosteronism. The apparently more severe phenotype in women may be related to the effects of female sex hormones on expression or function of NCCT.

Gitelman syndrome and pregnancy

Gitelman syndrome (GS) is an autosomal-recessive condition characterized by hypokalemia, hypomagnesemia and hypocalciuria. Very little information is available in the literature to guide the management of pregnant patients with GS. We report a case of a 27-year-old woman with GS who became pregnant and despite persistent hypokalemia and hypomagnesemia during pregnancy and labor, had a successful maternal and fetal outcome.