Nutrition and medical support during pregnancy and lactation in women with inborn errors of intermediary metabolism disorders (IEMDs)

Micronutrient Deficiency in Inherited Metabolic Disorders Requiring Diet Regimen: A Brief Critical Review

Many inherited metabolic disorders (IMDs), including disorders of amino acid, fatty acid, and carbohydrate metabolism, are treated with a dietary reduction or exclusion of certain macronutrients, putting one at risk of a reduced intake of micronutrients. In this review, we aim to provide available evidence on the most common micronutrient deficits related to specific dietary approaches and on the management of their deficiency, in the meanwhile discussing the main critical points of each nutritional supplementation. The emerging concepts are that a great heterogeneity in clinical practice exists, as well as no univocal evidence on the most common micronutrient abnormalities. In phenylketonuria, for example, micronutrients are recommended to be supplemented through protein substitutes; however, not all formulas are equally supplemented and some of them are not added with micronutrients. Data on pyridoxine and riboflavin status in these patients are particularly scarce. In long-chain fatty acid oxidation disorders, no specific recommendations on micronutrient supplementation are available. Regarding carbohydrate metabolism disorders, the difficult-to-ascertain sugar content in supplementation formulas is still a matter of concern. A ketogenic diet may predispose one to both oligoelement deficits and their overload, and therefore deserves specific formulations. In conclusion, our overview points out the lack of unanimous approaches to micronutrient deficiencies, the need for specific formulations for IMDs, and the necessity of high-quality studies, particularly for some under-investigated deficits.

Lysinuric Protein Intolerance and Its Nutritional and Multisystemic Challenges in Pregnancy: A Case Report and Literature Review

Lysinuric protein intolerance (LPI) is a rare inborn error of metabolism (IEM), classified as an inherited aminoaciduria, caused by mutations in the SLC7A7 gene, leading to a defective cationic amino acid transport. The metabolic adaptations to the demands of pregnancy and delivery cause significant physiological stress, so those patients affected by IEM are at greater risk of decompensation. A 28-year-old woman with LPI had experienced 3 early miscarriages. While pregnancy was finally achieved, diverse nutritional and medical challenges emerged (food aversion, intrauterine growth restriction, bleeding risk, and preeclampsia suspicion), which put both the mother and the fetus at risk. Moreover, the patient requested a natural childbirth (epidural-free, delayed cord clamping). Although the existence of multiple safety concerns rejected this approach at first, the application of novel strategies made a successful delivery possible. This case reinforces that the woman's wish for a non-medicated, low-intervention natural birth should not be automatically discouraged because of an underlying complex metabolic condition. Achieving a successful pregnancy is conceivable thanks to the cooperation of interdisciplinary teams, but it is still important to consider the risks beforehand in order to be prepared for possible additional complications.

Maternal-fetal outcomes of pregnancies in women treated at an inborn errors of metabolism unit

INTRODUCTION

Intermediate Inborn Errors of Metabolism (IEM) are a group of inherited diseases that include phenylketonuria (PKU), tyrosinemia II (TSII), organic acidaemias and ornithine transcarbamylase deficiency (OTCD), among others. They are increasingly more common in adults due to improved management. This has allowed more affected women to consider having children with good prospects. However, pregnancy may worsen metabolic control and/or increase maternal-fetal complications. The objective is to analyse the characteristics and outcomes of pregnancies of our patients with IEM.

METHODS

Retrospective descriptive study. Pregnancies of women with IEM attended to at the adult IEM referral unit of the Hospital Universitario Virgen del Rocío were included. The qualitative variables were described as n(%) and the quantitative as P50 (P25-P75).

RESULTS

24 pregnancies were recorded: 12 newborns were healthy, 1 inherited their mother's disease, 2 had maternal phenylketonuria syndrome, 1 was stillborn (gestational week 31 + 5), 5 were spontaneous abortions and 3 were voluntarily terminated. The gestations were divided into metabolically controlled and uncontrolled.

CONCLUSIONS

Pregnancy planning and multidisciplinary management through to postpartum is essential to ensure maternal and fetal health. The basis of treatment in PKU and TSII is a strict protein-limited diet. Events that increase protein catabolism in organic acidaemias and DOTC should be avoided. Further investigation of pregnancy outcomes in women with IEM is needed.

Current Scenario of Clinical Diagnosis to Identify Inborn Errors of Metabolism with Precision Profiling for Expanded Screening in Infancy in a Resource-limited Setting

Inborn errors of metabolism (IEM) are a diverse collection of abnormalities that cause a variety of morbidities and mortality in children and are classified as uncommon genetic diseases. Early and accurate detection of the condition can save a patient's life. By aiding families as they navigate the experience of having a child with an IEM, healthcare practitioners have the chance to reduce the burden of negative emotional consequences. New therapeutic techniques, such as enzyme replacement and small chemical therapies, organ transplantation, and cellular and gene-based therapies using whole-genome sequencing, have become available in addition to traditional medical intake and cofactor treatments. In the realm of metabolic medicine and metabolomics, the twentyfirst century is an exciting time to be alive. The availability of metabolomics and genomic analysis has led to the identification of a slew of novel diseases. Due to the rarity of individual illnesses, obtaining high-quality data for these treatments in clinical trials and real-world settings has proven difficult. Guidelines produced using standardized techniques have helped enhance treatment delivery and clinical outcomes over time. This article gives a comprehensive description of IEM and how to diagnose it in patients who have developed clinical signs early or late. The appropriate use of standard laboratory outcomes in the preliminary patient assessment is also emphasized that can aid in the ordering of specific laboratory tests to confirm a suspected diagnosis, in addition, to begin treatment as soon as possible in a resource limiting setting where genomic analysis or newborn screening facility is not available.

Diagnosis and Management of Inborn Errors of Metabolism in Adult Patients in the Emergency Department

Inborn errors of metabolism (IEM) constitute an important group of conditions characterized by an altered metabolic pathway. There are numerous guidelines for the diagnosis and management of IEMs in the pediatric population but not for adults. Given the increasing frequency of this group of conditions in adulthood, other clinicians in addition to pediatricians should be aware of them and learn to identify their characteristic manifestations. Early recognition and implementation of an appropriate therapeutic approach would improve the clinical outcome of many of these patients. This review presents when and how to investigate a metabolic disorder with the aim of encouraging physicians not to overlook a treatable disorder.

Complicated peripartum course in a patient with very long-chain acyl-coenzyme A dehydrogenase (VLCAD) deficiency

Very long-chain acyl-coenzyme A (CoA) dehydrogenase (VLCAD) deficiency is an autosomal recessive fatty acid oxidation disorder characterized by rhabdomyolysis, hypoglycemia and cardiomyopathy. The general treatment approach in adult patients is based on the prevention of catabolism. High carbohydrate, low fat diet and supplementation of medium-chain triglycerides are essential in the treatment. There is little experience with pregnancy follow-up in this patient group. We present a complicated peripartum course and successful management in a patient with VLCAD deficiency. Although high-dose glucose infusion was initiated, creatine kinase levels significantly increased in the immediate postpartum period, but the patient remained asymptomatic and rhabdomyolysis resolved rapidly after increasing the glucose infusion rate.

Perinatal free carnitine and short chain acylcarnitine blood concentrations in 12,000 full-term breastfed newborns in relation to their birth weight

BACKGROUND

Free carnitine (C0) and short chain acylcarnitine (SCA) blood concentrations play a significant role in fatty acid oxidation process during the first days of life. The aim of this study was to demonstrate C0 and SCA concentrations in Dried Blood Spots (DBS) of full term breastfed infants in relation to their birth weight (BW) perinatally.

METHODS

Breastfed full term infants (n = 12,000, 6000 males, 6000 females) with BW 2000-4000 g were divided into 4 equal groups: Group A, 2000-2500 g, B 2500-3000 g, C 3000-3500 g and D 3500-4000 g. Blood samples in the form of DBS were collected on the 3rd day of life and analyzed via a liquid chromatography tandem mass spectrometry (LC-MS/MS) protocol.

RESULTS

BW-related C0 and SCAs were found as follows: C0 was determined to be statistically significantly higher in group A (BW 2000-2500 g) in both males and females. Lower acetylcarnitine (C2) and hydroxybutyrylcarnitine (C4OH) blood concentrations were detected in group A of both sexes, whereas butyrylcarnitine (C4) concentrations were found to be lower in the same group of males only. Furthermore, high concentrations of C2 and C4OH were shown in group D (BW 3500-4000 g) in both sexes. SCA sum of means ± SD values in males and females of group A were statistically significantly lower as compared to other study groups.

CONCLUSION

Due to the number of the samples, data from this study could be applied as neonatal screening reference values for full term breastfed newborns in relation to their birth weight.

Current perspective and scope of fetal therapy: part 2

Fetal therapy has been defined as any therapeutic intervention either invasive or noninvasive for correcting or treating any fetal malformation or condition. Invasive fetal therapy have its own set of maternal and fetal complications and invasive approach is not feasible in many of fetal conditions that are candidate for fetal therapy. Many such fetal conditions have been treated successfully by medical or noninvasive management. In medical fetal therapy, mothers are treated with medications which are transferred to fetus through placenta and exert positive effect on the fetus, thus avoiding complications that are seen secondary to invasive fetal therapy. The fetal conditions that have been managed with medical therapy includes fetal and neonatal alloimmune thrombocytopenia, neural tube defect, congenital adrenal hyperplasia, perinatal infections, respiratory distress syndrome, inborn error of metabolism, and congenital cystic adenomatoid malformation. This review will cover the medical or noninvasive aspect of fetal therapy and will highlight the progress made in the management of these fetal conditions.

Regulation of maternal-fetal metabolic communication

Pregnancy may be the most nutritionally sensitive stage in the life cycle, and improved metabolic health during gestation and early postnatal life can reduce the risk of chronic disease in adulthood. Successful pregnancy requires coordinated metabolic, hormonal, and immunological communication. In this review, maternal-fetal metabolic communication is defined as the bidirectional communication of nutritional status and metabolic demand by various modes including circulating metabolites, endocrine molecules, and other secreted factors. Emphasis is placed on metabolites as a means of maternal-fetal communication by synthesizing findings from studies in humans, non-human primates, domestic animals, rabbits, and rodents. In this review, fetal, placental, and maternal metabolic adaptations are discussed in turn. (1) Fetal macronutrient needs are summarized in terms of the physiological adaptations in place to ensure their proper allocation. (2) Placental metabolite transport and maternal physiological adaptations during gestation, including changes in energy budget, are also discussed. (3) Maternal nutrient limitation and metabolic disorders of pregnancy serve as case studies of the dynamic nature of maternal-fetal metabolic communication. The review concludes with a summary of recent research efforts to identify metabolites, endocrine molecules, and other secreted factors that mediate this communication, with particular emphasis on serum/plasma metabolomics in humans, non-human primates, and rodents. A better understanding of maternal-fetal metabolic communication in health and disease may reveal novel biomarkers and therapeutic targets for metabolic disorders of pregnancy.