Angiotensin-II receptor 1 antagonist fetopathy--risk assessment, critical time period and vena cava thrombosis as a possible new feature

Overdose of angiotensin II receptor blocker in the third trimester of pregnancy: A case report

Angiotensin II receptor blockers (ARBs) are contraindicated during pregnancy because of fetal toxicity. All previous reports on adverse fetal outcomes involved women who continued to take low-dose ARBs for hypertension and were unaware of the adverse effects. Herein, we report the case of a 23-year-old pregnant woman in her third trimester who experienced an ARB overdose after an argument with her partner. Pregnancy was complicated by transient oligohydramnios, and fetal magnetic resonance imaging suggested renal failure. Despite these concerns, the newborn had no morphological abnormalities or abnormal neurological findings. Renal impairment improved over time, and the infant grew well. A single overdose of ARBs in the third trimester can lead to fetal renal failure, similar to long-term low-dose ARB administration; however, favorable outcomes are possible. An overdose of ARBs may transiently cause renal failure, which may improve. The study findings may inform counseling for women who are unexpectedly exposed to an overdose of ARBs.

Quantifying Proximal Collecting Tubule Deficiency in Angiotensin-Converting Enzyme Inhibitor and Angiotensin II Receptor Blocker Fetopathy

INTRODUCTION

Angiotensin-Converting Enzyme Inhibitors and Angiotensin II Receptor Blockers (AAs) are used for several indications, with cessation recommended in pregnancy due to toxic effects. AA fetopathy phenotype is similar to renal tubular dysgenesis including reduced proximal convoluted tubules (PCTs). Our study aimed to quantify the reduction of PCTs in fetuses and infants with prenatal exposure to AAs.

MATERIALS AND METHODS

We identified 5 fetal AA exposure cases that underwent autopsy at our institution between 2011 and 2018 and compared with 5 gestational age-matched controls. Immunohistochemistry with CD10 and epithelial membrane antigen (EMA) was utilized.

RESULTS

CD10 and EMA identified a median PCT density of 19.0% ± 12.3% in AA fetopathy patients, significantly less than controls (52.8% ± 4.4%; p < 0.0001). One case with in utero cessation had a PCT density of 34.2% ± 0.2%. Among other AA fetopathy findings, 1 case demonstrated unilateral renal vein thrombosis and 4 had hypocalvaria.

CONCLUSIONS

We have quantified the reduction in AA fetopathy PCT density, and demonstrated in utero cessation may recover PCT differentiation. Future studies may benefit from calculating PCT percentage as a potential biomarker to correlate with post-natal renal function and maternal factors including medication type, dosage, duration, and time from medication cessation.

Valsartan exposure in pregnancy with resultant anhydramnios and chronic kidney disease in a late preterm infant

In utero exposure to angiotensin II receptor blockers (ARBs) has fetotoxic effects including renal failure, oligohydramnios and lung hypoplasia. We present the case of a 24-year-old woman who presented to the maternity services in the 34th week of her first pregnancy. She was taking valsartan for hypertension. Ultrasound showed a structurally normal fetus with anhydramnios. The patient was admitted and valsartan was discontinued. She had spontaneous preterm delivery at 35 weeks' gestation of a baby girl. The baby's urine output was minimal in the first week of life and she was transferred to a paediatric hospital for specialist nephrology input. At 6 months of age, she requires ongoing nephrology follow-up and she remains on treatment for hypertension and anaemia. This case demonstrates the serious adverse effects resulting from ARB exposure in utero, and highlights the importance of avoiding fetotoxic medications in women of childbearing age.

Fetotoxic risk of AT1 blockers exceeds that of angiotensin-converting enzyme inhibitors: an observational study

OBJECTIVE

The fetotoxic potential of prenatal exposure to angiotensin-converting enzyme inhibitors (ACE-I) and angiotensin II receptor blockers (ARBs) has been known for many years. Symptoms range from transient oligohydramnios to neonatal anuria and permanent renal damage, joint contractures, hypocalvaria, lung hypoplasia and intrauterine or neonatal death. This study aims to investigate the critical gestational time for renin-angiotensin system inhibitor (RAS-I)-induced fetopathy, to quantify the fetopathy risk and to evaluate factors associated with the occurrence and severity of fetopathy.

METHODS

Prospectively and retrospectively ascertained RAS-I exposed pregnancies from the databases of six teratology information services were analyzed.

RESULTS

Eighty-nine pregnancies with ACE-I and 101 with ARB exposure beyond the first trimester were identified. Fifty-nine of these 190 pregnancies were classified as having evidence of RAS-I fetopathy. All pregnancies affected with fetopathy were exposed after 20 0/7 gestational weeks. Limited to prospectively enrolled cases with exposure at least 20 0/7 gestational weeks, the rate of fetopathy was 3.2% for ACE-I and 29.2% for ARB. The chance of recovery of amniotic fluid volume was higher with RAS-I discontinuation before 30 gestational weeks and with a longer exposure-free interval before delivery.

CONCLUSION

Exposure to ARBs is associated with a higher fetopathy risk than exposure to ACE-Is. RAS-I should ideally be discontinued prior to pregnancy or immediately after recognition of pregnancy. Because symptoms may improve in cases of RAS-I-induced oligohydramnios, pregnancy should be maintained as long as there is fetal well being. Physicians and patients need to be alerted to the fetotoxic risks of RAS-I.

Massive thrombosis in an infant with suspected nephrocalcinosis: case report and literature review

Introduction

Perinatal period is characterized by an increased risk of thrombosis due to low resources and limited compensatory capacity of the coagulation system in early stages of life.

Case report

We report a case of a second pregnancy female infant born at 39 weeks by caesarean section, due to pre-labor rupture of membranes, with body weight of 3,570 γ and Apgar score 10. The pregnancy was complicated by hypothyroidism, uterine myoma, urinary tract infections, and mother's appendectomy at 16 Hbd. At 3 months, the girl was admitted to our hospital due to kidney calcifications, which were incidentally found during ultrasound scan. In laboratory workup, no abnormalities in calcium and phosphate homeostasis were detected. However, in ultrasound scan, linear calcifications along pyramids were visualized in both kidneys. Due to atypical location of nephrocalcinosis, Doppler scan was performed, showing lack of visible blood flow from renal veins to inferior vena cava (IVC), with compensatory flow from renal veins to paravertebral plexuses, and IVC obliteration with a massive calcification in the hepatic section. Magnetic resonance confirmed obliteration of IVC and common iliac veins, segmental dilatation of IVC, and compensatory blood flow from kidneys and lower limbs to paravertebral plexuses. Clinical picture and formation of collateral circulation suggested intrauterine thrombosis. Congenital thrombophilia was excluded in laboratory examination.

Conclusions

The differential diagnosis of calcifications in renal parenchyma (nephrocalcinosis) should include renal vein thrombosis. Massive fetal and perinatal thrombosis can be asymptomatic due to high ability to form collateral circulation at the early stage of life.

Successful kidney transplantation in a small child with end-stage renal disease due to angiotensin receptor blocker fetopathy and atretic inferior vena cava

Kidney transplantation is the treatment of choice in pediatric patients with end-stage renal disease. This population presents technical challenges particularly in those less than 20 kg due to anomalous anatomy, vascular access issues prior to transplantation, and a generally small size for age. Standard allograft outflow is usually achieved utilizing the iliac veins or IVC. When use of the iliocaval system is not feasible, alternative anastomosis must be considered. Herein, we report a case of a pediatric kidney transplantation where successful allograft outflow was achieved using the SMV when he was found to have an atretic IVC intraoperatively. In this setting, use of the portal system was required to achieve adequate allograft outflow. We created a donor iliac graft for added length to anastomose the renal vein with the SMV. In the setting of IVC occlusion with poor drainage, we utilized a patent vessel with larger caliber for outflow to reduce the risk of high venous pressures, allograft failure, venous rotation, and thrombosis. We conclude that the SMV may serve as an alternative outflow tract in the small pediatric patient and provides the vessel caliber needed to reduce the risks of complications.

[Drug safety in pregnancy-a particular challenge]

Drug safety in pregnancy is of utmost importance because prenatal exposure to the unborn child may result in side effects with life-long consequences. Data on their risks in pregnancy are scarce for many drugs. Furthermore, there is often uncertainty how to translate risk data into practice.This article aims to identify tools to improve data ascertainment on exposed pregnancies and their outcome. Using the example of the German Embryotox institute, it is demonstrated how to disseminate drug safety knowledge to healthcare professionals and patients for clinical decision-making.Observational data are the most important basis for drug risk assessment in pregnancy. Such data are collected by Embryotox through the risk consultation process. Prospective cohort studies with comparison cohorts allow to estimate relative risks for birth defects, pregnancy loss, and other developmental anomalies. Retrospectively ascertained adverse drug reactions contribute to identification of distinct pattern of congenital anomalies.Drugs in pregnancy counselling require risk characterization dependent on the individual clinical setting: recommendation of treatment of choice (comparative risk assessment between effective drugs), individual risk estimation after (inadvertent) exposure, and assessment of causal relationship in cases of congenital anomalies. Combining counselling and protocols of pregnancy outcome after drug exposure is optimal to cost-efficiently ascertain data of high quality.Using acetaminophen, valproic acid, AT1-receptor blockers and retinoids as examples, recent discussions on drug risks in pregnancy and their clinical implications are presented.

Treatment and Prevention of Hypertensive Disorders During Pregnancy

This article reviews the pharmacology of the most commonly used antihypertensive medications during pregnancy; their mechanism of action; and the effects on the mother, the fetus, and lactation. Each class of antihypertensive pharmacologic agents have specific mechanisms of action by which they exert their antihypertensive effect. β-Adrenoreceptor antagonists block these receptors in the peripheral circulation. Calcium channel blockers result in arterial vasodilation. α-Agonists inhibit vasoconstriction. Methyldopa is a centrally acting adrenoreceptor antagonist. Vasodilators have a direct effect on vascular smooth muscle. Diuretics decrease intravascular volume. Medications acting on the angiotensin pathway are avoided during pregnancy because of fetotoxic effects.

Pregnancy outcome after first trimester use of angiotensin AT1 receptor blockers: an observational cohort study

BACKGROUND

Ongoing discussion about the safety of renin-angiotensin inhibitors in the first trimester and limited data on pregnancy outcomes after exposure to angiotensin AT1 receptor blockers (ARBs).

METHODS

Observational cohort study compares outcomes of 215 prospectively ascertained pregnancies with first trimester exposure to ARBs with 642 non-hypertensive pregnancies.

RESULTS

The rate of major birth defects in the ARB cohort (9/168, 5.4%) was higher than in the comparison group (17/570, 3%), but not significantly increased (OR_adj 1.9, 95% CI 0.7-4.9). There was no distinct pattern of anomalies among infants with birth defects. The risk of spontaneous abortions was not increased (HR_adj 0.9, 95% CI 0.5-1.6), although the cumulative incidence was in the upper normal range (0.22, 95% CI 0.15-0.32). Higher rates of prematurity (OR_adj 3.0; 95% CI 1.7-5.1) and a reduced birth weight after adjustment for sex and gestational age were observed. There was no evidence for an increased risk for major birth defects, spontaneous abortions, or preterm birth in a sensitivity analysis comparing ARB exposed hypertensive women to hypertensive women without ARB exposure during the first trimester.

CONCLUSION

Our study supports the hypothesis that ARBs are not major teratogens. Patients inadvertently exposed to ARBs during the early pregnancy may be reassured. Nevertheless, women planning pregnancy should avoid ARBs. In selected cases, ARBs might be continued under careful monitoring of menstrual cycle and discontinued as soon as pregnancy is recognized.

Long-Term Consequences of Fetal Angiotensin II Receptor Antagonist Exposure

Fetal angiotensin II receptor antagonist exposure is associated with major complications and even death when administered during pregnancy. Neonates frequently require intensive care treatment, and mortality is high. Despite this well-known risk potential, a considerable number of women still receive angiotensin II receptor antagonists during pregnancy to treat arterial hypertension. Although clinical symptoms in the neonatal period are well described, few reports address long-term follow-up after fetal exposure to angiotensin II receptor antagonists. We here report on a patient who was unwittingly exposed to olmesartan medoxomil during pregnancy. After birth, the neonate presented with mild clinical symptoms, mainly affecting the kidneys. However, neurodevelopmental follow-up revealed a delay in motor development with muscular hypotonia and failure to thrive at age 2 years. This case highlights the fact that, despite not causing neurological symptoms in the neonatal period, fetal angiotensin II receptor antagonist exposure during pregnancy might lead to neurodevelopmental impairment in later life.

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.

Drug safety in pregnancy: the German Embryotox institute

Since 1988, the German Embryotox institute combines individual counselling of pregnant women and their health care providers (HCP) with research on drug safety in pregnancy. In addition, Embryotox offers web-based information which covers the most important and most frequently requested pharmaceutical substances. In contrast to ready-made drug risk information in package leaflets and other product information, individual counselling considers different clinical settings such as (1) looking for a drug of choice or planning pregnancy under medication, (2) risk assessment of a particular drug that has already been taken during an (unplanned) pregnancy and (3) evaluation of an adverse pregnancy outcome in association with a particular medication. Using the three established developmental toxicants valproic acid, isotretinoin, and renin-angiotensin-aldosterone system (RAAS) inhibitors as an example, the need of detailed information is illustrated. Through the risk communication process, pregnancy outcome data are routinely collected by Embryotox. This approach uses the advantages of a pre-existing communication structure and of dealing with motivated responders. Engagement in the treatment plan facilitates receiving reliable data on drug exposure as well as detailed follow-up data. Based on these patient records, prospective datasets are evaluated in observational cohort studies in comparison to non-exposed control cohorts. In addition, retrospective datasets received as suspected adverse drug reactions from multiple German sources allow a screening for signals of teratogenicity and distinct patterns of developmental toxicity. Clinical expertise in specialties such as teratology, paediatrics, embryology, obstetrics and human genetics are required to ensure high-quality assessment of drug safety in pregnancy.

Utility of an Algorithm to Increase the Accuracy of Medication History in an Obstetrical Setting

Background

In an obstetrical setting, inaccurate medication histories at hospital admission may result in failure to identify potentially harmful treatments for patients and/or their fetus(es).

Methods

This prospective study was conducted to assess average concordance rates between (1) a medication list obtained with a one-page structured medication history algorithm developed for the obstetrical setting and (2) the medication list reported in medical records and obtained by open-ended questions based on standard procedures. Both lists were converted into concordance rate using a best possible medication history approach as the reference (information obtained by patients, prescribers and community pharmacists’ interviews).

Results

The algorithm-based method obtained a higher average concordance rate than the standard method, with respectively 90.2% [CI_95% 85.8–94.3] versus 24.6% [CI_95%15.3–34.4] concordance rates (p<0.01).

Conclusion

Our algorithm-based method strongly enhanced the accuracy of the medication history in our obstetric population, without using substantial resources. Its implementation is an effective first step to the medication reconciliation process, which has been recognized as a very important component of patients’ drug safety.

Neonatal acute kidney injury following Valsartan exposure in utero: report of two cases

BACKGROUND

Maternal sartan intake during pregnancy has been associated with several fetal/neonatal complications related to disturbed renal development. Description of cases: We present two cases of neonatal acute kidney injury (AKI) following valsartan administration during pregnancy and provide evidence for the use of novel AKI biomarkers in these neonates. The first case was a female neonate, delivered at 32+4 weeks of gestation after maternal valsartan intake from 24 to 32 gestational weeks. In the second case, ultrasound examination revealed a growth-restricted fetus with severe oligohydramnios following maternal valsartan intake during the first 29 gestational weeks. In the absence of any improvement in amniotic fluid, the neonate was born at 31+5 weeks. In both cases, AKI was documented after birth, but renal function progressively recovered. Urine cystatin-C and neutrophil gelatinase-associated lipocalin were found abnormally increased during the first week of life.

CONCLUSION

Sartan use during pregnancy is associated with the development of neonatal AKI. Novel urine biomarkers may be used to document renal injury. Hippokratia 2016, 20(1): 73-75.

Renin Angiotensin System Blocker Fetopathy: A Midwest Pediatric Nephrology Consortium Report

OBJECTIVES

Fetuses continue to be exposed to renin angiotensin system (RAS) blockers despite their known teratogenicity and a black box warning. We hypothesized that fetopathy from in utero exposure to RAS blockers has a broader spectrum of clinical manifestations than described previously and that there are a variety of clinical scenarios leading to such exposures.

STUDY DESIGN

This was a retrospective study performed through the Midwest Pediatric Nephrology Consortium. Cases of RAS blocker fetopathy were identified, with determination of renal and extrarenal manifestations, timing of exposure, and the explanation for the fetal exposure.

RESULTS

Twenty-four cases were identified. RAS blocker exposure after the first trimester was associated with more severe renal manifestations. Chronic dialysis or kidney transplantation was required in 8 of 17 (47%) patients with RAS blocker exposure after the first trimester and 0 of 7 patients with exposure restricted to the first trimester (P = .05). Extrarenal manifestations, some not previously noted in the literature, included central nervous system anomalies (cystic encephalomalacia, cortical blindness, sensorineural hearing loss, arachnoid cysts) and pulmonary complications (pneumothorax, pneumomediastinum). RAS blocker exposure usually was secondary to absent or poor prenatal care or undiagnosed pregnancy.

CONCLUSION

RAS blocker fetopathy continues to be a cause of considerable morbidity, with more severe renal manifestations associated with exposure after the first trimester. A variety of significant extrarenal manifestations occur in these patients. Clinicians should emphasize the risk of fetopathy when prescribing RAS blockers to women of childbearing age.

Postnatal acute renal failure after fetal exposure to angiotensin receptor blockers

Maternal hypertensive treatment with angiotensin receptor blockers (ARBs) during the second and third trimester of pregnancy is associated with several fetal and neonatal complications, and potential adverse outcomes. We report a neonate presenting with transient renal acute failure during the first days of life after maternal treatment with ARBs. Women who became pregnant while taking one of these drugs must modify antihypertensive therapy with a different class drug as soon as pregnancy is recognised.

Organic Anion Transporter 4-Mediated Transport of Olmesartan at Basal Plasma Membrane of Human Placental Barrier

Mechanisms regulating fetal transfer of olmesartan, an angiotensin-II receptor type 1 antagonist, are important as potential determinants of life-threatening adverse fetal effects. The purpose of this study was to examine the olmesartan transport mechanism through the basal plasma membrane (BM) of human syncytiotrophoblasts forming the placental barrier. Uptake of olmesartan by human placental BM vesicles was potently inhibited by dehydroepiandrosterone sulfate (DHEAS), estrone 3-sulfate, and bromosulfophthalein, which are all typical substrates of organic anion transporter (OAT) 4 localized at the BM of syncytiotrophoblasts, and was increased in the absence of chloride. In tetracycline-inducible OAT4-expressing cells, [(3) H]olmesartan uptake was increased by tetracycline treatment. Olmesartan uptake via OAT4 was concentration dependent with a Km of 20 μM, and was increased in the absence of chloride. [(3) H]Olmesartan efflux via OAT4 was also observed and was trans-stimulated by extracellular chloride and DHEAS. Thus, OAT4 mediates bidirectional transport of olmesartan and appears to regulate fetal transfer of olmesartan at the BM of syncytiotrophoblasts. Efflux transport of olmesartan via OAT4 from syncytiotrophoblasts to the fetal circulation might be facilitated in the presence of an inwardly directed physiological chloride gradient and extracellular DHEAS.