Hypercalcemia in pregnancy - a multifaceted challenge: case reports and literature review

Significance of vitamin D responsiveness on the etiology of vitamin D-related diseases

Vitamin D resistance (VDRES) explains the necessity for higher doses of Vitamin D (VD) than those recommended for treatment success. VD receptor (VDR) signaling blockade, such as that caused by infections and poisons, is one basis for VDRES etiology. Mutations within genes affecting the VD system cause susceptibility to developing low VD responsiveness and autoimmunity. In contrast, VD hypersensitivity (VDHY) occurs if there is extra VD in the body; for example, as a result of an overdose of a VD supplement. Excess 1,25(OH)2D3 is produced in lymphomas and granulomatous diseases. The placenta produces excess 1,25(OH)2D3. Gene mutations regulating the production or degradation of 1,25(OH)2D3 enhance the effects of 1,25(OH)2D3. Increased 1,25(OH)2D3 levels stimulate calcium absorption in the gut, leading to hypercalcemia. Hypercalcemia can result in the calcification of the kidneys, circulatory system, or placenta, leading to kidney failure, cardiovascular disease, and pregnancy complications. The primary treatment involves avoiding exposure to the sun and VD supplements. The prevalence rates of VDRES and VDHY remain unclear. One estimate was that 25%, 51%, and 24% of the patients had strong, medium, and poor responses, respectively. Heavy-dose VD therapy may be a promising method for the treatment of autoimmune diseases; however, assessing its potential side effects is essential. To avoid VD-mediated hypercalcemia, responsiveness must be considered when treating pregnancies or cardiovascular diseases associated with VD. Furthermore, how VD is associated with the related disorders remains unclear. Investigating responsiveness to VD may provide more accurate results.

Calcium-alkali syndrome as a rare cause of severe hypercalcemia requiring dialysis in early twin gestation

Hypercalcemia is rare in women of child-bearing age, and most cases are due to primary hyperparathyroidism. A 28-year-old woman, 14 weeks pregnant with dichorionic diamniotic twins, presented to hospital with vomiting, muscle cramps, and weakness. She had been taking calcium carbonate for gastric reflux and nausea from 5 weeks of gestation. Investigations revealed severe hypercalcemia, metabolic alkalosis, and renal injury. She was transferred to intensive care, receiving fluid resuscitation and subcutaneous calcitonin followed by dialysis. Investigations revealed suppressed PTH and PTH-related peptide, negative malignancy screening and low vitamin D level. Calcium and renal function quickly normalized and with cessation of calcium carbonate remained normal throughout the rest of pregnancy. Reports of calcium-alkali syndrome causing severe hypercalcemia are scarce, with most cases occurring later in gestation. This case represents a dramatic presentation requiring renal replacement therapy early in twin gestation.

Challenges in the management of hypercalcemia in pregnancy - Case report of two cases

Hypercalcemia in pregnancy is rare and can pose a great diagnostic challenge due to its asymptomatic presentation. It is associated with maternal complications such as urolithiasis, pancreatitis, renal insufficiency and preeclampsia, fetal complications such as growth restriction and intrauterine fetal demise, and neonatal complications such as neonatal hypocalcemia, tetany and hypoparathyroidism. Prompt diagnosis and treatment of the underlying cause of hypercalcemia is important. Two cases of hypercalcemia in pregnancy were encountered over 12 months. Both presented asymptomatically in the first trimester and were associated with hyperparathyroidism and hypertensive disease in current and previous gestations. Genetic testing ruled out familial hypocalciuric hypercalcemia, and both women required surgical management in the second trimester for control of hypercalcemia. The literature on the diagnosis and management of hypercalcemia in pregnancy is reviewed, and the challenges and pitfalls are discussed. Hypercalcemia in pregnancy requires a high index of suspicion for early diagnosis, and young women with unexplained hypertension in early pregnancy should be investigated for secondary causes, including hypercalcemia and primary hyperparathyroidism. Management of hypercalcemia secondary to primary hyperparathyroidism requires multidisciplinary team management, and surgery should be considered if the patient has not responded to conservative measures, ideally in the second trimester.

Primary Hyperparathyroidism during Pregnancy: Two Tales with Different Outcomes

Primary hyperparathyroidism (PHPT) is rare in pregnancy. This condition is challenging to diagnose and manage due to the limited diagnostic and therapeutic options that are safe during pregnancy. If not diagnosed and managed in a timely manner, serious maternal and foetal complications may occur. We report two cases, one with surgical intervention and one without, to show the importance of timely surgical intervention and discuss the challenges in the management of PHPT in pregnancy.

Association of hypertension in pregnancy with serum electrolyte disorders in late pregnancy among Cameroonian women

Multiple electrolyte disorders, including sodium, potassium and calcium disorders, have been associated with hypertension in pregnancy. Most of these studies failed to evaluate the combined effect of low and high sodium, potassium, calcium and chloride ion concentrations on hypertension in pregnancy. This study evaluates the combined effect of these ion categories (low, normal, high) on hypertension in pregnancy. Biochemical ion assays and blood pressure measurements were carried out on 1074 apparently healthy pregnant women in late third trimester. Serum potassium, sodium, chloride, and ionised calcium were measured by ion-selective electrode potentiometry, while total plasma calcium was measured by absorption spectrophotometry. Hypertension in pregnancy was defined as systolic blood pressure ≥ 140 mmHg and/or diastolic blood pressure ≥ 90 mmHg. The prevalence of hyponatraemia, hypokalaemia, hypochloraemia, ionised hypocalcaemia and total hypocalcaemia in late pregnancy was 1.30 [0.78-2.18]%, 3.55 [2.60-4.84]%, 1.96 [1.28-2.97]%, 1.49 [0.92-2.21]% and 43.58 [40.64-46.56]%, respectively. Hypernatraemia, hyperkalaemia, hyperchloraemia, ionised hypercalcaemia and total hypercalcaemia were found in 1.49 [0.92-2.41]%, 2.34 [1.59-3.43]%, 4.38 [3.31-5.77]%, 39.94 [37.06-42.90]%, 2.79 [1.96-3.96]% of the participants, respectively. The prevalence of hypertension in pregnancy was 7.17 [5.77-8.87]%. When ion categories were considered in multiple logistic regression, only ionised and total calcium had significant associations with hypertension in pregnancy. Women with ionised hypercalcaemia had lower odds of hypertension in pregnancy (AOR = 0.50 [0.29-0.87], p-value = 0.015), and women with total hypocalcaemia had higher odds of hypertension in pregnancy (AOR = 1.99 [1.21-3.29], p-value = 0.007), compared to women with ionised and total normocalcaemia, respectively. Increasing kalaemia was associated significantly with higher odds of hypertension in pregnancy; however, kalaemia below and above the normal concentrations had no significant association with hypertension. Nonetheless, participants with kalaemia ≤ 3.98 mmol/L, had lower odds of hypertension in pregnancy compared with those with higher kalaemia (OR = 0.40 [0.24-0.66], p-value = 0.0003). Calcium disorders remain the most frequent electrolyte disorders in pregnancy. When normal cut-offs are considered for calcium and other ions, only ionised and total calcium influence the occurrence of hypertension in pregnancy. Kalaemia seems to affect hypertension in pregnancy but primarily within its normal concentrations. Serum electrolyte follow-up is indispensable for a proper pregnancy follow-up.

[Diagnosis and management of primary hyperparathyroidism during pregnancy: A systematic review and a longitudinal case study]

OBJECTIVE

There is no specific recommendation for management in pregnant women: the aim of this review, based on a clinical case study, is to clarify its development, complications, risk factor and treatment.

METHODS

A review of the literature was performed by consulting the Pubmed, Cochrane Library, and Science Direct databases.

RESULTS

Primary hyperparathyroidism is defined as excessive production of parathyroid hormone resulting in hypercalcemia. The prevalence of primary hyperparathyroidism during pregnancy is not known. Indeed, the symptomatology, related to hypercalcemia, is not very specific and easily confused with the clinical manifestations of pregnancy. The physiological changes specific to the pregnant state frequently lead to a slight hypocalcemia which may complicate the diagnosis of primary hyperparathyroidism. Primary hyperparathyroidism results from a parathyroid adenoma in the majority of cases and is detected by ultrasound during pregnancy. Primary hyperparathyroidism in pregnancy causes significant risks to both mother and fetus. The maternal complication rate is 14-67%, however, the most serious complication is hypercalcemic crisis, which requires increased surveillance in the postpartum period. Obstetrical complications are also induced by primary hyperparathyroidism, such as acute polyhydramnios, or intrauterine growth retardation. The fetal complication rate can reach 45-80% of cases with neonatal hypocalcemia as the main complication. If medical treatment is based on hyperhydration, only surgical treatment is curative.

CONCLUSION

Surgery should be proposed to symptomatic patients or those with high blood calcium levels, discussed in interdisciplinary committee and should be organized ideally in the second trimester to avoid maternal and fetal complications.

Expert consensus on multidisciplinary approach to the diagnosis and treatment of primary hyperparathyroidism in pregnancy in China

Primary hyperparathyroidism in pregnancy is a rare disease that can have detrimental effects on both maternal and fetal/neonatal outcomes. The physiological changes that occur during pregnancy can complicate the diagnosis, imaging examinations, and treatment of this disorder. To enhance our understanding and management of primary hyperparathyroidism in pregnancy, experts from various fields, including endocrinology, obstetrics, surgery, ultrasonography, nuclear medicine, pediatrics, nephrology, and general practice in China, collaborated to develop a consensus addressing the critical aspects of the diagnosis and treatment of primary hyperparathyroidism in pregnancy with a multidisciplinary team approach. This consensus provides valuable guidance for healthcare professionals in managing this condition, ultimately improving outcomes for both mothers and their babies.

Calcium, Potassium, Sodium, and Magnesium Concentrations in the Placenta, Umbilical Cord, and Fetal Membrane from Women with Multiple Pregnancies

Calcium (Ca), potassium (K), sodium (Na), and magnesium (Mg) are the elements responsible for the fundamental metabolic and biochemical processes in the cells of the body. The demand for these elements increases significantly during pregnancy, where an adequate supply protects women from the hypertension common in pre-eclampsia and preterm labor. This study aimed to evaluate the association between macro-elements (Ca, Mg, Na, and K) in the placenta, fetal membrane, and umbilical cord and the morphometric parameters of newborns from multiple pregnancies. The study involved 57 pregnant European women with healthy uncomplicated twin pregnancies (n = 52) and triple pregnancies (n = 5); 40 pairs of dichorionic diamniotic twins, 11 pairs of monochorionic diamniotic twins, 1 pair of monochorionic monoamniotic twins, 3 trichorionic triamniotic triplets, and 2 dichorionic triamniotic triplets. Placentas (n = 107), umbilical cords (n = 114), and fetal membranes (n = 112) were collected immediately following delivery, and then weighed and measured. The levels of Ca, K, Na, and Mg were determined using inductively coupled plasma atomic emission spectroscopy (ICP-OES) in a Thermo Scientific ICAP 7400 Duo (Waltham, MA, USA). The respective mean concentrations of Ca, K, Na, and Mg (mg/kg^-1 dry mass) were: 2466, 8873, 9323, and 436 in the placenta; 957, 6173, 26,757, and 326 in the umbilical cord, and 1252, 7460, 13,562, and 370 in the fetal membrane. In the studied materials from northwestern Poland, we found strong positive correlations between Ca and Mg concentrations in both the umbilical cord (r = 0.81, p = 0.00) and the fetal membrane (r = 0.73, p = 0.00); between K and Mg concentrations in the umbilical cord (r = 0.73, p = 0.00); between Ca and K concentrations in the fetal membrane (r = 0.73, p = 0.00), and we found moderately positive correlations between placental Ca concentration and placental weight (ρ = 0.42, p = 0.00) and between umbilical cord Mg concentrations and the length of the pregnancy (ρ = 0.42, p = 0.00). Negative correlations were found between Na and Ca concentrations in the fetal membrane (r = -0.40, p = 0.00) and Na concentrations in the fetal membrane and Mg concentrations in the placenta (r = -0.16, p = 0.02). Negative correlations were confirmed between the length of pregnancy and head circumference (ρ = -0.42; p = 0.00), infant weight (ρ = -0.42; p = 0.00), infant length (ρ = -0.49; p = 0.00), shoulder width (ρ = -0.49; p = 0.00); and between the infant weight and head circumference (ρ = -0.62; p = 0.00), weight before delivery (ρ = -0.36; p = 0.00), infant length (ρ = -0.45; p = 0.00), shoulder width (ρ = -0.63; p = 0.00), and weight gain during pregnancy (ρ = -0.31; p = 0.01). We found statistically significant correlations between cigarette smoking before pregnancy and the women's weight before delivery (ρ = 0.32, p = 0.00), and a negative correlation between the women's ages and infant head circumference (ρ = -0.20, p = 0.02). This is probably the first study to evaluate Ca, Na, K, and Mg concentrations in the afterbirth tissues of multiple pregnancies. It adds to the knowledge of elemental concentrations in multiple pregnancies and their possible effects on fetal morphometric parameters.

Different treatment strategies in primary hyperparathyroidism during pregnancy

PURPOSE

Primary hyperparathyroidism (PHPT) in pregnancy is rare enough and can be unrecognized because of nonspecific symptoms in most cases, but life-threatening complications for mother, fetus and neonate also occurs. PHPT requires frequent monitoring of the mother and fetus by a multidisciplinary team. Diagnostics and treatment approaches are limited and require individual risk-benefit assessment.

METHODS

In this paper we describe 3 cases of PHPT in pregnant women with different managing approaches (surveillance, drug therapy and surgical treatment) and successful outcomes. Additionally, the most actual literature data on this problem is reviewed.

RESULTS

The management of PHPT in pregnancy should be based on the clinical features, severity of hypercalcemia, gestational age and patient's preference. In the first case a conservative approach with low-calcium diet and oral hydration resulted in mother's reduced serum calcium level before delivery. The second patient had severe hypercalcemia and absolute indications for surgery that was successfully performed at 25 week of gestation. The third woman received cinacalcet because of severe hypercalcemia and potential perioperative risks in the third trimester with an improvement in well-being.

CONCLUSION

Nowadays parathyroidectomy is the best choice for patients with symptomatic PHPT and severe hypercalcemia. This intervention should be carried out preferably in the second trimester to avoid maternal and fetal complications. Mild forms of the disease can require just a conservative management. The drug treatment of PHPT during pregnancy is still controversial.

Parathyroid carcinoma presenting with ventricular bigeminy in pregnancy

Parathyroid carcinoma is very rare in pregnancy. Clinical features are similar to primary hyperparathyroidism. A 38-year-old pregnant woman had repeated hospital admissions for palpitations, headaches, dizziness and polydipsia. Blood investigations showed severe hypercalcaemia with raised parathyroid hormone and 24-hour ECG showed ventricular bigeminy and premature ventricular contractions. Neck ultrasound showed a lesion in the right thyroid lobe. Consequently, she underwent an en bloc resection of the right parathyroid and thyroid lobe at 23 weeks gestation. Histology results confirmed parathyroid cancer. This case highlights the complexities of identifying hypercalcaemia in pregnancy due to the overlapping features with common disorders of pregnancy. Early recognition and timely surgical management can prevent maternal and fetal complications. Also, the case demonstrates the value of interprofessional collaboration between different specialities in providing quality care and improving outcomes. An abridged version of this case was presented at European Congress of Endocrinology 2021.

Fetomaternal Acid–Base Balance and Electrolytes during Pregnancy

A pregnant mother undergoes significant changes in acid-base status as well as sodium and calcium metabolism to combat her physiological needs of pregnancy. Pregnant patients experience mild respiratory alkalosis due to the stimulation of the respiratory center by progesterone. This is associated with a corresponding increase in bicarbonate excretion by kidneys; as a result, the pH remains slightly high (7.40–7.45) but within the normal range. Pregnant women are predisposed to starvation ketosis as compared to nonpregnant states due to relative insulin resistance and increased production of the counter-regulatory hormone. Physiological mild hyponatremia occurs during pregnancy due to increased AVP secretion caused by resetting of osmoreceptors in the hypothalamus at a lower osmolality, but values below 130 mEq/L require a diagnostic workup and intervention. Gestational diabetes insipidus can occur due to increased production or decreased destruction of enzyme vasopressinase. Secretion of parathyroid hormone-related peptide by the placenta and breasts and two- to three-fold increased calcium and phosphate absorption in the maternal gut are the key changes in calcium metabolism during pregnancy. Though rare, both hypo- and hypercalcemia in pregnancy are associated with significant maternofetal morbidity and mortality.

Hypercalcemia in Pregnancy

Hypercalcemic disorders are rare in pregnant women and are usually due to primary hyperparathyroidism. Clinical manifestations of hypercalcemia are nonspecific and can be masked by the physiologic changes of pregnancy. Furthermore, routine antenatal screening does not include serum calcium measurement and a hypercalcemia diagnosis may therefore be delayed until term or even after delivery. Timely recognition and appropriate interventions are essential to decrease maternal and fetal complications. Conservative measures are appropriate in the presence of mild hypercalcemia. Parathyroidectomy remains the mainstay of treatment for primary hyperparathyroidism with significant hypercalcemia not responding to conservative measures.

Primary hyperparathyroidism in pregnancy: observations from the Indian PHPT registry

PURPOSE

To present the data on primary hyperparathyroidism (PHPT) in pregnancy from India obtained from a large database maintained over 15 years.

METHODS

We retrieved data of all women with gestational PHPT from the Indian PHPT registry between July 2005 and January 2020, and compared their clinical, biochemical, and other characteristics with age-matched non-pregnant women with PHPT.

RESULTS

Out of 386 women, eight had gestational PHPT (2.1%). The common presenting manifestations were acute pancreatitis (50%) and renal stone disease (50%); two were asymptomatic. Five women (62.5%) had a history of prior miscarriages. Seven patients (88%) had preeclampsia during the present gestation. Serum calcium and intact parathyroid hormone (iPTH) were not statistically different from the age-matched non-pregnant PHPT group. Six patients with mild-to-moderate hypercalcemia were medically managed with hydration with/without cinacalcet while one patient underwent percutaneous ethanol ablation of the parathyroid adenoma; none underwent surgery during pregnancy. Mean serum calcium maintained from treatment initiation till delivery was 10.5 ± 0.4 mg/dl. One patient had spontaneous preterm delivery at 36 weeks; the remaining patients had normal vaginal delivery at term. None had severe preeclampsia/eclampsia. Fetal outcomes included low birth weight in three newborns (37.5%); two of them had hypocalcemic seizures.

CONCLUSION

The prevalence of gestational PHPT was 2.1% in this largest Indian PHPT cohort, which is higher than that reported from the West (< 1%). Gestational PHPT can lead to preeclampsia and miscarriage. Pregnant PHPT patients with mild-to-moderate hypercalcemia can be managed with hydration/cinacalcet; however, long-term safety data and large-scale randomized controlled trials are required.

Primary Hyperparathyroidism in Pregnancy: Literature Review of the Diagnosis and Management

Background: Parathyroid disease is uncommon in pregnancy. During pregnancy, multiple changes occur in the calcium regulating hormones which may make the diagnosis of primary hyperparathyroidism more challenging. Close monitoring of serum calcium during pregnancy is necessary in order to optimize maternal and fetal outcomes. In this review, we will describe the diagnosis and management of primary hyperparathyroidism during pregnancy. Methods: We searched MEDLINE, CINAHL, EMBASE and Google scholar bases from 1 January 1990 to 31 December 2020. Case reports, case series, book chapters and clinical guidelines were included in this review. Conclusions: Medical management options for primary hyperparathyroidism during pregnancy are severely limited due to inadequate safety data with the various potential therapies available, and surgery is advised during the 2nd trimester of pregnancy in the presence of severe hypercalcemia (calcium adjusted for albumin greater than 3.0 mmol/L (12.0 mg/dL)). Hypercalcemia should be avoided during pregnancy in order to minimize maternal and fetal complications.

Primary hyperparathyroidism presenting as a brown tumor with hypercalcemia crisis in a second-trimester pregnant woman: A case report

INTRODUCTION

Primary hyperparathyroidism (PHPT) in pregnancy is rare and unrecognized because the maternal physiological adaptations blurs the symptoms. There is no standard treatment strategy for maternal PHPT. Early diagnosis and interventions can prevent catastrophic consequences to the mother and fetus.

PATIENT CONCERNS

A 31-year-old Chinese woman was admitted, due to a lump on the left lower leg for 4 months. The patient complained of mild pain in the left lower leg following exercise that could be relieved after a short rest. The patient was at 18 weeks of gestation, and the growth of the fetus was normal. The patient has a 3-year history of hypercalcemia and a 2-year history of nephrolithiasis. No family history of hypercalcemia and endocrine tumors were present.

DIAGNOSIS

Laboratory tests demonstrated high serum calcium level of 3.84 mmol/L, parathyroid hormone 1393 pg/mL, alkaline phosphatase 488 μ/L. Ultrasound showed a 22.4 mm × 7.8 mm solid nodule in the left lower lobe of the thyroid gland. Based on these findings, the patient was diagnosed with PHPT.

INTERVENTIONS

The patient accepted continuous renal replacement to reduce ironized calcium level. Parathyroidectomy was performed at the 19th week of gestation. Threatened abortion occurred 2 days after the surgery, and magnesium sulfate was used to prevent the abortion. Calcium gluconate, calcium carbonate and vitamin D3 were used to treat the hypocalcemia that occurred 5 days after the surgery.

OUTCOMES

Pathology examination demonstrated the parathyroid adenoma. Abortion was prevented using magnesium sulfate and hypocalcemia was cured with calcium gluconate, calcium carbonate and vitamin D3. At 38-week of gestation, the patient (ionized calcium level: 2.16 mmol/L) delivered a healthy female baby weighing 2700 g with 10/10 Apgar. Till now, both the mother and infant showed no complications.

CONCLUSION

Maternal PHPT is rare and challenging to diagnose, causing life-threatening complications to mother and fetus. Any decision regarding surgery for a pregnant woman with primary hyperparathyroidism is more complex than in men or nonpregnant women. The decision should be made based on the severity of hypercalcemia and symptoms.

Complexities surrounding the diagnosis and management of hypercalcaemia in pregnancy

SUMMARY

Hypercalcaemia in pregnancy is uncommon, with associated adverse obstetric and perinatal outcomes for both the mother and the fetus. Determination of causality is central to its management. Diagnostic imaging techniques are limited during pregnancy and the diagnosis is made more complex by physiological changes in calcium and vitamin D homeostasis in pregnancy. Further, therapeutic options are limited due to safety considerations for the pregnant woman and the developing foetus. Three cases of hypercalcaemia in pregnancy will be presented, highlighting the distinct aetiologies and management strategies for hypercalcaemia in pregnancy and the importance of early measurement of serum calcium in pregnancy screening.

LEARNING POINTS

There are complex physiological changes in calcium balance in pregnancy, including increased calcium intestinal absorption and renal excretion. Hypercalcaemia in pregnancy is uncommon but has important potential maternal and foetal complications, making a compelling argument for routine antenatal, calcium screening. Identifying the cause of hypercalcaemia in pregnancy can be challenging due to the complex placental interplay in biochemical test interpretation and due to safety constraints restricting imaging and surgery. Acute medical management of hypercalcaemia must be considered in the context of both maternal and foetal well-being, along with gestational age and specific consideration for the safety of the developing fetus in late gestation.

Hypercalcemia Resulting from Necrotizing Leiomyoma in a Pregnant Female

Patient: Female, 38-year-old

Final Diagnosis: Hypercalcemia resulting from necrotizing leiomyoma in pregnancy

Symptoms: Pain

Medication: —

Clinical Procedure: Cesarean section

Specialty: General and Internal Medicine • Obstetrics and Gynecology

Biallelic CYP24A1 variants presenting during pregnancy: clinical and biochemical phenotypes

INTRODUCTION

Inactivating mutations in CYP24A1, encoding vitamin D-24-hydroxylase, can lead to an accumulation of active vitamin D metabolites and consequent hypercalcaemia. Patient (infantile and adult) presentation is varied and includes mild-severe hypercalcaemia, hypercalciuria, nephrocalcinosis and nephrolithiasis. This study aimed to characterize the clinical and biochemical phenotypes of a family with two CYP24A1 missense variants.

METHODS

The proband and seven family members underwent detailed clinical and biochemical evaluation. Laboratory measurements included serum calcium, intact parathyroid hormone (iPTH), vitamin D metabolites and urine calcium and creatinine.

RESULTS

The proband presented during the second trimester of a planned pregnancy with flu-like symptoms. Laboratory tests showed elevated adjusted calcium of 3.27 (upper reference limit (URL: 2.30) mmol/L), suppressed iPTH (<6 ng/L), elevated 25(OH)D (264 (URL: 55) nmol/L) and elevated 1,25(OH)D (293 (URL: <280) pmol/L). Ionized calcium was 1.55 (URL: 1.28) mmol/L. Sanger sequencing revealed two heterozygous missense variants in the CYP24A1: p.(Arg439Cys), R439C and p.(Trp275Arg), W275R. The proband's brother and sister had the same genotype. The brother had intermittent hypercalcaemia and hypervitaminosis D. Only the sister had a history of nephrolithiasis. The proband's daughter and two nephews were heterozygous for the R439C variant. The proband and her brother frequently had elevated 25(OH)D:24,25(OH)2D ratios (>50) during follow-up.

CONCLUSIONS

W275R is a new pathogenic CYP24A1 mutation in compound heterozygotic form with R439C in this family.

Gestational hypercalcemia: Prevalence and biochemical profile

Gestational hypercalcemia is associated with an increased risk of maternal, fetal and neonatal morbidity and mortality. Hypercalcemia may develop during pregnancy in individuals who were previously asymptomatic. The increased sensitivity during pregnancy may be related to physiological, gestational alterations in vitamin D and calcium metabolism and may be influenced by gene variants. The prevalence is unknown. We investigated the prevalence of hypercalcemia in trimester 3 (T3) in a population representative prospective cohort study (n = 1832) in South-West Sweden. Women with serum albumin (Alb) adjusted calcium (Ca_Alb) ≥ 2.65 mmol/L in T3 (n = 30) were matched to normo-calcemic controls, and markers of calcium and vitamin D metabolism were investigated in trimester 1 (T1) and T3. Serum concentrations of Ca, phosphate (P), Magnesium (Mg), Alb and creatinine (Cr), parathyroid hormone (PTH; T3 only), vitamin D metabolites (total 25(OH)D, 1,25(OH)₂D, 24,25(OH)₂D, and free 25(OH)D) were analysed in T1 and T3. Ca_Alb (Payne; inter-laboratory difference: UEA = 0.15 + 0.9*UGOT; UEA 2.54 = UGOT 2.65) and estimated glomerular filtration rate (eGFR; modified 4-variable MDRD) and vitamin D metabolites ratios (VMR) were calculated. Normally and non-normally distributed data were presented as mean (SD) or median (95 %CI). Group differences in relationships between vitamin D metabolites and with PTH were investigated with multiple regression analyses. Hypercalcemia in T3 was found in 1.7 % of women. PTH concentrations suggestive of primary hyperparathyroidism was found in 1 woman and none had 25(OH)D or 24,25(OH)₂D concentrations in the toxicity range or suggestive of mutations in the CYP24A1 gene. Ca_Alb was significantly higher in hypercalcemic cases compared to controls in T1 (2.44 (2.30-2.80) vs 2.37 (2.25-2.49) mmol/L) and T3 (2.63 (2.52-2.78) vs 2.46 (2.31-2.58) mmol/L). Serum P was higher among cases than controls in T3 (1.12 (0.16) vs 1.07 (0.18) mmol/L) but not in T1 (1.12 (0.18) and 1.12 (0.16) mmol/L). PTH in T3 was lower in cases (1.6 (1.6-2.8) vs 2.3 (2.1-2.8) pmol/L) but 1,25(OH)₂D concentrations were similar. There were no significant group differences in serum 25(OH)D, free 25(OH)D, 24,25(OH)₂D, Mg, Alb, Cr and eGFR. Regression analyses did not show significant differences between cases and controls in relationships between vitamin D metabolites and with PTH, except for the free 25(OH)D-PTH relationship and a higher free:total 25(OH)D ratio in cases at T1. In conclusion, most common causes of hypercalcemia were excluded in the majority of women. Hypercalcemic women had a relatively high serum 1,25(OH)₂D concentration despite an appropriately suppressed PTH, suggestive of abnormal gestational adaptions.

Impact of Perinatal Primary Hyperparathyroidism on Maternal and Fetal and Neonatal Outcomes: Retrospective Case Series

OBJECTIVE

We sought to describe the maternal, fetal, and neonatal outcomes of primary hyperparathyroidism in a contemporary setting through a retrospective case series conducted in a tertiary referral centre focused on women diagnosed with primary hyperparathyroidism prior to conception, in the antepartum period, or within 6 weeks postpartum.

METHODS

A retrospective chart review was conducted and data were abstracted to case report forms. Summary statistics are reported.

RESULTS

From 2000 to 2017, 19 women (23 pregnancies) with primary hyperparathyroidism were identified. Most women (79%) were symptomatic at presentation, though often with non-specific manifestations. While 14% of pregnancies involved maternal/obstetric complications, fetal/neonatal complications were observed in 45%. Mild hypercalcemia was identified in 57% of women, with accompanying hypophosphatemia and hypomagnesemia in 46% and 36% of women, respectively. Surgical intervention was performed for 89% women, and no complications were encountered. Normal calcium levels achieved through treatment before conception did not fully eliminate adverse outcomes.

CONCLUSION

Rates of perinatal complications in our series are more reassuring than the ubiquitously quoted rates from small and dated studies. The diagnosis of primary hyperparathyroidism may be easily missed during pregnancy, owing to its non-specific presentation. A high index of suspicion and measurement of ionized calcium levels is encouraged, especially for patients with excessive nausea and vomiting, nephrolithiasis, atypical presentations of hypertensive disorders, or isolated polyhydramnios. Mild degrees of calcium derangement do not preclude adverse perinatal outcomes. Surgery appears to be safe, even in the third trimester. The attenuated rate of complications noted in our series may have been the result of the high proportion of surgery, though this will require verification via meta-analysis or future prospective work.

Hyperparathyroidism in pregnancy

Hyperparathyroidism is a rare disease during pregnancy, which has increased risks, including miscarriage and fetal growth restriction. However, the diagnosis of hyperparathyroidism is frequently not recognised or delayed as symptoms are non-specific and calcium is not routinely measured. With a thorough medical history and clinical suspicion, early diagnosis and treatment can reduce the risk of some pregnancy complications. A 35-year-old woman presented at 13/40 with hyperemesis gravidarum. She had elevated serum calcium and a parathyroid lesion on ultrasound. She underwent a parathyroidectomy with rapid normalisation of her calcium. Histopathology confirmed a parafibromin-deficient parathyroid tumour, suggestive of hyperparathyroidism jaw tumour syndrome. At 30/40, she presented with pre-eclampsia (hypertension, hyper-reflexia, proteinuria and intrauterine growth restriction) and had a caesarean section at 30+1/40, delivering a male infant, 897 g (fifth percentile). She had a prior 12-month history of chronic constipation and nephrolithiasis but was not investigated further despite elevated calcium (2.82 mmol/L).

A hemodialysis patient with bone disease after pregnancy: a case report

Background

Pregnancy is rare in women on hemodialysis. Recommendations for the treatment of secondary hyperparathyroidism (sHPT) and preservation of bone health in pregnant dialysis patients are lacking.

Case presentation

We present the case of a young woman with end-stage kidney disease (ESKD) due to lupus nephritis, who developed multiple brown tumors while on hemodialysis during her second pregnancy. During her first pregnancy sHPT was well controlled and no skeletal complications occurred. Before the second pregnancy she developed severe sHPT. During pregnancy, dialysis time was increased to 24 h per week, the patient was given oral calcitriol, and the dialysate calcium concentration was set at 1.5 mmol/l. In week 20 the patient complained about bone pain in her left hip. Magnetic resonance imaging revealed a cystic lesion compatible with a brown tumor. The baby was delivered in the 36th week by cesarean section. Further assessment identified multiple brown tumors of her skeleton, including the acetabulum, tibia, ribs, skull, thoracic spine and thumb. She required multiple orthopedic surgeries. Three months after pregnancy, etelcalcetide was started, which brought about a gradual improvement in her sHPT.

Conclusions

This case demonstrates that the combination of pregnancy and severe sHPT in dialysis patients can have deleterious consequences for bone health.

A CASE OF HYPERPARATHYROIDISM TREATED WITH CINACALCET DURING PREGNANCY

Objective

Hyperparathyroidism during pregnancy is associated with increased maternal and neonatal complications. Cinacalcet is a calcimimetic medication that is used in the treatment of hyperparathyroidism; its use in pregnancy is limited to a few case reports.

Methods

Case report and literature review.

Results

We are reporting on a 37-year-old patient who was admitted to the hospital with dyspnea at 24 weeks gestation. A routine blood test revealed hypercalcemia; corrected calcium level was 3.17 mmol/L, and parathyroid hormone was elevated at 168 pg/mL. The patient was asymptomatic. Following her last delivery 10 years previously, her newborn developed severe tetany and needed treatment with intravenous (IV) calcium. Neck ultrasound was normal. Due to obesity and history of recurrent deep venous thrombosis, neck exploration was not favored. Initial treatment included calcitonin and IV fluids. The aim was to keep her calcium level as normal as possible to avoid any fetal complications. She was started on cinacalcet 15 mg once per day, which was increased later to 15 mg twice daily. By 36 weeks gestation, corrected calcium levels were down to <2.60 mmol/L. The patient was scheduled to deliver via elective cesarean section at 38 weeks, but she presented at 37 weeks in labor pain and delivered via emergency cesarean section. Postdelivery, the neonate calcium levels remained normal.

Conclusion

During pregnancy, parathyroid surgery is the recommended treatment. Cinacalcet could be one of the options in severe cases of hypercalcemia if surgery cannot be performed. Further studies are needed to examine the safety of cinacalcet in pregnancy.

Hypercalcaemia during pregnancy: Review of maternal and fetal complications, investigations, and management

Introduction

Asymptomatic mild primary hyperparathyroidism is increasingly being identified during pregnancy. Recent studies have demonstrated inconsistent findings with regard to pregnancy complications and the need for surgical intervention during pregnancy.

Method

A retrospective audit of outcomes of pregnancies complicated by hypercalcaemia over a 15-year period was performed.

Results

Twenty-nine pregnancies to 26 women with hypercalcaemia were identified, corresponding to 37 cases per 100,000 deliveries. Hypercalcaemia was due to primary hyperparathyroidism in 90% of cases, with mean serum calcium of 2.89 mmol/l and mean ionised calcium 1.43 mmol/l. Four women underwent successful neck exploration during pregnancy. Pregnancy complications were limited to three cases of pre-eclampsia and one case of symptomatic neonatal hypoparathyroidism.

Conclusion

Close observation without surgical intervention would seem reasonable in women with mild hypercalcaemia during pregnancy.

Changes in biochemical tests in pregnancy and their clinical significance

Interpretation of laboratory investigations relies on reference intervals. Physiological changes in pregnancy may result in significant changes in normal values for many biochemical assays, and as such results may be misinterpreted as abnormal or mask a pathological state. The aims of this review are as follows: 1. To review the major physiological changes in biochemical tests in normal pregnancy. 2. To outline where these physiological changes are important in interpreting laboratory investigations in pregnancy. 3. To document the most common causes of abnormalities in biochemical tests in pregnancy, as well as important pregnancy-specific causes.

Hypercalcemic crisis in third trimenon: evaluating the optimal treatment strategy

Hypercalcemia due to primary hyperparathyroidism during pregnancy is a rare condition and associated with increased morbidity and mortality for the mother and the unborn child. Whereas parathyroidectomy is favored during the second trimester, no clear recommendations exist for its management during the third trimenon. We here report the case of a 26-year-old woman in the 29th week of her first pregnancy, who was admitted to our clinic with hypertension, intra-uterine growth retardation and polyhydramnios. Severe hypercalcemia due to primary hyperparathyroidism was diagnosed (total calcium 3.34 mmol/l; PTH 216 pg/ml), but no enlarged parathyroid gland could be localized by ultrasound. Treatment with calcitonin and cinacalcet could not control hypercalcemia. Therefore explorative surgery was performed and a single parathyroid adenoma was resected, resulting in normalization of serum calcium levels. The surgical procedure was tolerated well by the mother and fetus. Hypercalcemia-induced hypertension and polyhydramnios ameliorated before C-section was performed two weeks later and unrelated to the intervention. This case report underlines the importance of early diagnosis and treatment of primary hyperparathyroidism during pregnancy. If diagnosed in the third trimenon, an interdisciplinary approach is crucial. If medical treatment fails to sufficiently control hypercalcemia, surgical parathyroid exploration should be considered even in cases of unsuccessful localization of adenomatous parathyroid glands.

Undiagnosed Primary Hyperparathyroidism and Recurrent Miscarriage: The First Prospective Pilot Study

Background

Primary hyperparathyroidism (pHPT) in pregnancy is reported to be associated with significant maternal and foetal complications and an up to threefold increase in the risk of miscarriage. However, the true incidence of pHPT in pregnancy, complete and miscarried, is unknown and there are no data on the prevalence of undiagnosed pHPT in recurrent miscarriage (RM) (≥3 consecutive miscarriages under 24-week gestation). This is the first prospective study aiming to establish the prevalence of undiagnosed pHPT in RM.

Methods

Following UK National ethics committee approval, women who had experienced 3 or more consecutive miscarriages were recruited from a nationwide RM clinic. Serum corrected calcium, phosphate, PTH and vitamin D were evaluated. Patients with raised serum calcium and/or PTH were recalled for confirmatory tests. Power calculations suggested that a minimum of 272 patients were required to demonstrate a clinically significant incidence of pHPT.

Results

Three hundred women were recruited, median age 35 years (range 19–42). Eleven patients had incomplete data, leaving 289 patients suitable for analysis; 50/289 patients (17%) with abnormal tests were recalled. The prevalence of vitamin D deficiency (<25 nmol/l) and insufficiency (25–75 nmol/l) was 8.7 and 67.8%, respectively. One patient was diagnosed with pHPT (0.34%) and underwent successful parathyroidectomy.

Conclusions

The prevalence of undiagnosed pHPT (0.34%) in RM in this study appears to be many times greater than the 0.05% expected in this age group. The findings of this pilot study merit follow-up with a larger-scale study. Routine serum calcium estimation is not currently undertaken in RM and should be considered.

Juvenile onset IIH and CYP24A1 mutations

The term Idiopathic infantile hypercalcemia (IIH) was first introduced almost 70 years ago when symptomatic hypercalcemia developed in children after receiving high doses of vitamin D for the prevention of rickets. The underlying pathophysiology remained unknown until recessive mutations in CYP24A1 encoding Vitamin D₃-24-hydroxylase were discovered. The defect in vitamin D degradation leads to an accumulation of active 1,25(OH)₂D₃ with subsequent hypercalcemia. Enhanced renal calcium excretions lead to hypercalciuria and nephrocalcinosis. Meanwhile, the phenotypic spectrum associated with CYP24A1 mutations has significantly broadened. Patients may present at all age groups with symptoms originating from increased serum calcium levels as well as from increased urinary calcium excretions, i.e. kidney stones. Possible long term sequelae comprise chronic renal failure as well as cardiovascular disease. Here, we present a family with two affected siblings with differing clinical presentation as an example for the phenotypic variability of CYP24A1 defects.

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CYP24A1 mutations result in increased vitamin D sensitivity.

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Associated phenotypes range from infantile hypercalcemia to kidney stone disease.

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Potential long-term sequelae include chronic renal failure.

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Future research needs to focus on potential treatments to limit vitamin D activation.

Review article: Investigations and the pregnant woman in the emergency department - part 1: Laboratory investigations

Accurate assessment of the pregnant patient in the ED depends on knowledge of physiological changes in pregnancy, and how these changes may impact on pathology tests, appearance on point-of-care ultrasound and electrocardiography. In addition the emergency physician needs to be cognisant of disorders that are unique to or more common in pregnancy. Part 1 of this review addresses potential deviations in laboratory investigation reference intervals resulting from physiological alterations in pregnancy, and the important causes of abnormal laboratory results in pregnancy. Part 2 will address the role of point-of-care ultrasound in pregnancy, physiological changes that may affect interpretation of point-of-care ultrasound, physiological changes in electrocardiography, and the safety of radiological procedures in the pregnant patient.

Gestational Primary Hyperparathyroidism Due to Ectopic Parathyroid Adenoma: Case Report and Literature Review

Gestational primary hyperparathyroidism (GPHPT) is a rare condition with fewer than 200 cases reported. We present the case of a 21-year-old woman who presented at 10 weeks’ gestation with severe hypercalcemia. Laboratory investigation was consistent with primary hyperparathyroidism. Neck ultrasound did not reveal any parathyroid enlargement. Due to the persistence of severe hypercalcemia, she was treated with 4 weeks of cinacalcet therapy, which was poorly tolerated due to nausea and vomiting. At 14 weeks’ gestation, she underwent neck exploration with right lower, left upper, and partial right upper parathyroid gland excision. Intra- and postoperative parathyroid hormone (PTH) and calcium levels remained elevated. After a thorough discussion of risks/benefits, the patient requested further treatment. A parathyroid sestamibi scan (PSS) revealed an ectopic adenoma in the left mediastinum. The adenoma was removed via video-assisted thorascopic parathyroidectomy with intraoperative PTH declining to nearly undetectable levels. She ultimately delivered a physically and developmentally normal infant at 37 weeks’ gestation.

Appropriate treatment of severe GPHPT may prevent the maternal and fetal complications of hypercalcemia. This case, in which cinacalcet therapy and PSS were used, adds to the body of literature regarding treatment of severe GPHPT.