Anesthetic Management of Mitochondrial Encephalopathy With Lactic Acidosis and Stroke-Like Episodes (MELAS Syndrome) in a High-Risk Pregnancy: A Case Report

A retrospective cohort study evaluating pregnancy outcomes in women with MIDD

AIMS

The most common pathogenic mitochondrial mutation associated with mitochondrial disease is m.3243A>G. Increased obstetric complications, such as spontaneous abortion, gestational diabetes (GDM), preterm delivery, and preeclampsia, have been reported in women carrying this mutation. We aimed to determine the fetal and maternal outcomes in pregnant women with mitochondrial disease.

METHODS

We retrospectively studied the obstetric and perinatal outcomes in 88 pregnancies of 26 women with genetically confirmed mitochondrial disease (m.3243A>G in the MTTL1 gene (n = 25); m.12258C>A in the MT-TS2 gene (n = 1)). Outcomes included pregnancy related complications, mode of delivery, gestational age at delivery and birthweight.

RESULTS

Mean heteroplasmy rate was 18%. The miscarriage rate was higher than background at 25%. 21 pregnancies (24%) were complicated by GDM; 9 pregnancies (13.6%) had a preterm delivery and 2 of them (3%) an extreme premature delivery < 32 weeks. One woman had preeclampsia and one had a postpartum hemorrhage. The caesarean section (CS) rate was 20%. For every unit increase in maternal heteroplasmy levels there was a 26% increased risk of undergoing an assisted operative vaginal delivery (OR 1.26, 95% CI 1.04-1.53, P = 0.002, Bonferroni corrected P = 0.005) and an 18% increased risk of undergoing a CS (OR 1.18, 95% CI 1.01-1.39, P = 0.01, Bonferroni corrected P = 0.03) compared to a spontaneous vaginal delivery. There was a statistical significant correlation between maternal and offspring heteroplasmy levels. Spearman correlation rho = 0.96, 95% CI 0.78-0.99, P = 0.0002.

CONCLUSION

Women with mitochondrial disease appear to have more frequent obstetric complications including miscarriage and GDM. Pre-pregnancy diagnosis of m.3243A>G will enable the counseling of women and increase awareness of possible obstetric complications.

Renal manifestations in adults with mitochondrial disease from the mtDNA m.3243A>G pathogenic variant

Mitochondrial diseases are a phenotype and genotype heterogeneous group of disorders that typically have a multisystemic involvement. The m.3243A>G pathogenic variant is the most frequent mitochondrial DNA defect, and it causes several different clinical syndromes, such as mitochondrial encephalopathy, lactic acidosis and stroke-like episodes (MELAS), and the maternally inherited diabetes and deafness (MIDD) syndromes. Not frequently reported, renal involvement in these diseases is probably underestimated, yet it increases morbidity. It generally manifests as subnephrotic proteinuria and progressive deterioration of kidney function. Adult presentation of mitochondrial diseases is hard to recognize, especially in oligosymptomatic patients or those with exclusive kidney involvement. However, suspicion should always arise when family history, particularly on the maternal side, and multisystemic symptoms, most often of the central nervous system and skeletal muscles, are present. In this review we discuss the clinical diagnosis and approach of patients with renal manifestations in the context of the mtDNA m.3243A>G pathogenic variant.

Obstetric involvement in mitochondrial disorders: A review

This is the first review about obstetric involvement in mitochondrial disorders (MIDs). The purpose of the review was to discuss recent advances and knowledge about the type and frequency of obstetric complications in MIDs. A narrative review for preferred reporting items was performed in MEDLINE, Current Contents, EMBASE, Web of Science, Web of Knowledge, LILACS, SCOPUS, and Google Scholar. The author searched for studies examining obstetric complications in patients with a definite MID. Obstetric complications described in MIDs include eclampsia, preeclampsia, intra uterine growth retardation, polyhydramnion, oligoamnion, decreased fetal movements, premature delivery, stillbirth, blow weakness, dystocia, breech presentation, retained placenta, postnatal hemorrhage, low birth weight, and early postnatal death. The most common of these complications are polyhydramnion, stillbirth, premature delivery, and low birth weight. The data show that some obstetric complications are more common in MIDs than in healthy females. MIDs can be associated with various obstetric complications. Some of these complications are more common in pregnant females with MID compared with healthy pregnant females. Obstetricians should be aware of MIDs and should know that pregnant females with a MID have an increased risk of developing complications during pregnancy or delivery.

Ischemic stroke and cerebral venous sinus thrombosis in pregnancy

Maternal ischemic stroke and cerebral venous sinus thrombosis (CVST) are dreaded complications of pregnancy and major contributors to maternal disability and mortality. This chapter summarizes the incidence and risk factors for maternal arterial ischemic stroke (AIS) and CVST and discusses the pathophysiology of maternal AIS and CVST. The diagnosis, treatment, and secondary preventive strategies for maternal stroke are also reviewed. Special populations at high risk of maternal stroke, including women with moyamoya disease, sickle cell disease, HIV, thrombophilia, and genetic cerebrovascular disorders, are highlighted.

Mitochondrial Disease (MELAS Syndrome) Discovered at the Start of Pregnancy in a Patient with Advanced CKD: A Clinical and Ethical Challenge

Pregnancy is a challenge in the life of a woman with chronic kidney disease (CKD), but also represents an occasion for physicians to make or reconsider diagnosis of kidney disease. Counselling is particularly challenging in cases in which a genetic disease with a heterogeneous and unpredictable phenotype is discovered in pregnancy. The case reported regards a young woman with Stage-4 CKD, in which "Mitochondrial Encephalopathy, Lactic Acidosis, and Stroke-like episodes" (MELAS syndrome), was diagnosed during an unplanned pregnancy. A 31-year-old Caucasian woman, being followed for Stage-4 CKD, sought her nephrologist's advice at the start of an unplanned pregnancy. Her most recent data included serum creatinine 2⁻2.2 mg/dL, Blood urea nitrogen (BUN) 50 mg/dL, creatinine clearance 20⁻25 mL/min, proteinuria at about 2 g/day, and mild hypertension which was well controlled by angiotensin-converting enzyme inhibitors (ACEi); her body mass index (BMI) was 21 kg/m² (height 152 cm, weight 47.5 kg). Her medical history was characterized by non-insulin-dependent diabetes mellitus (at the age of 25), Hashimoto's thyroiditis, and focal segmental glomerulosclerosis. The patient's mother was diabetic and had mild CKD. Mild hearing impairment and cardiac hypertrophy were also detected, thus leading to suspect a mitochondrial disease (i.e., MELAS syndrome), subsequently confirmed by genetic analysis. The presence of advanced CKD, hypertension, and proteinuria is associated with a high, but difficult to quantify, risk of preterm delivery and progression of kidney damage in the mother; MELAS syndrome is per se associated with an increased risk of preeclampsia. Preterm delivery, associated with neurological impairment and low nephron number can worsen the prognosis of MELAS in an unpredictable way. This case underlines the importance of pregnancy as an occasion to detect CKD and reconsider diagnosis. It also suggests that mitochondrial disorders should be considered in the differential diagnosis of kidney impairment in patients who display an array of other signs and symptoms, mainly type-2 diabetes, kidney disease, and vascular problems, and highlights the difficulties encountered in counselling and the need for further studies on CKD in pregnancy.

Impact of pregnancy on inborn errors of metabolism

Once based mainly in paediatrics, inborn errors of metabolism (IEM), or inherited metabolic disorders (IMD) represent a growing adult medicine specialty. Individually rare these conditions have currently, a collective estimated prevalence of >1:800. Diagnosis has improved through expanded newborn screening programs, identification of potentially affected family members and greater awareness of symptomatic presentations in adolescence and in adulthood. Better survival and reduced mortality from previously lethal and debilitating conditions means greater numbers transition to adulthood. Pregnancy, once contraindicated for many, may represent a challenging but successful outcome. Successful pregnancies are now reported in a wide range of IEM. Significant challenges remain, given the biological stresses of pregnancy, parturition and the puerperium. Known diagnoses allow preventive and pre-emptive management. Unrecognized metabolic disorders especially, remain a preventable cause of maternal and neonatal mortality and morbidity. Increased awareness of these conditions amongst all clinicians is essential to expedite diagnosis and manage appropriately. This review aims to describe normal adaptations to pregnancy and discuss how various types of IEM may be affected. Relevant translational research and clinical experience will be reviewed with practical management aspects cited. Based on current literature, the impact of maternal IEM on mother and/or foetus, as well as how foetal IEM may affect the mother, will be considered. Insights gained from these rare disorders to more common conditions will be explored. Gaps in the literature, unanswered questions and steps to enhance further knowledge and systematically capture experience, such as establishment of an IEM-pregnancy registry, will be summarized.