Increased incidence of obstetric complications in women carrying mitochondrial DNA mutations: a retrospective cohort study in a single tertiary centre

Preimplantation genetic testing as a preventive strategy for the transmission of mitochondrial DNA disorders

Mitochondrial diseases are distinct types of metabolic and/or neurologic abnormalities that occur as a consequence of dysfunction in oxidative phosphorylation, affecting several systems in the body. There is no effective treatment modality for mitochondrial disorders so far, emphasizing the clinical significance of preventing the inheritance of these disorders. Various reproductive options are available to reduce the probability of inheriting mitochondrial disorders, including in vitro fertilization (IVF) using donated oocytes, preimplantation genetic testing (PGT), and prenatal diagnosis (PND), among which PGT not only makes it possible for families to have genetically-owned children but also PGT has the advantage that couples do not have to decide to terminate the pregnancy if a mutation is detected in the fetus. PGT for mitochondrial diseases originating from nuclear DNA includes analyzing the nuclear genome for the presence or absence of corresponding mutations. However, PGT for mitochondrial disorders arising from mutations in mitochondrial DNA (mtDNA) is more intricate, due to the specific characteristics of mtDNA such as multicopy nature, heteroplasmy phenomenon, and exclusive maternal inheritance. Therefore, the present review aims to discuss the utility and challenges of PGT as a preventive approach to inherited mitochondrial diseases caused by mtDNA mutations.

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.

Recent progress in metabolic reprogramming in gestational diabetes mellitus: a review

Gestational diabetes mellitus is a prevalent metabolic disease that can impact the normal course of pregnancy and delivery, leading to adverse outcomes for both mother and child. Its pathogenesis is complex and involves various factors, such as insulin resistance and β-cell dysfunction. Metabolic reprogramming, which involves mitochondrial oxidative phosphorylation and glycolysis, is crucial for maintaining human metabolic balance and is involved in the pathogenesis and progression of gestational diabetes mellitus. However, research on the link and metabolic pathways between metabolic reprogramming and gestational diabetes mellitus is limited. Therefore, we reviewed the relationship between metabolic reprogramming and gestational diabetes mellitus to provide new therapeutic strategies for maternal health during pregnancy and reduce the risk of developing gestational diabetes mellitus.

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.

Case Report: Kearns Sayre Syndrome Complicated With Postpartum Cardiac Failure

Kearns Sayre Syndrome (KSS) is a rare mitochondrial disease characterized by a primary dysfunction of the mitochondrial respiratory chain. Cardiac involvement is a poor prognostic factor of KSS. Pregnancy and delivery in a KSS patient with cardiac involvement is uncommon, and strategies for the supervision and management of this group remain unclear. Herein, we report and discuss pregnancy and delivery complicated with acute cardiopulmonary failure in a woman with KSS.

The non-syndromic clinical spectrums of mtDNA 3243A>G mutation

The m.3243A >G mutation in the tRNA Leu (UUR) gene (MT-TL1) of the mitochondrial DNA is the most widely seen pathogenic mtDNA mutation which has major phenotypic variations. The clinical phenotype involves various organs such as the brain and nerves, skeletal muscles, heart, endocrine system, gastrointestinal tract, and skin. Some phenotypes conform to well established syndromes, while most of the symptoms appear individually or concomitant to other syndromes, making identification difficult. Furthermore, some progress has been made on cardiac manifestations as well as complications during pregnancy and perinatal period. This article provides a systematic review of the non-syndromic phenotypes and latest developments in m.3243A>G mutation.