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

Objective To investigate the obstetric outcome of women carriers of the oxidative phosphorylation (OXPHOS) disorder mutation. Design A retrospective cohort study in a single tertiary centre. Setting A review of the obstetric history of women referred for prenatal screening of a mitochondrial disorder was performed. Population Women were divided into three groups: (1) women carrying mitochondrial DNA (mtDNA) mutations; (2) healthy women with a family history of mtDNA-related OXPHOS disorder; and (3) healthy women carrying heterozygote nuclear DNA mutations. Methods Obstetric history and pregnancy complications were evaluated separately in the three groups and compared with the control group. Main outcome measures pregnancy complications.Results Seventy-five women were included with 287 cumulative pregnancies. Groups 1 and 3 had a significantly greater proportion of terminations of pregnancy (20 and 13% versus 0.8%, P < 0.001), and a lower percentage of live births (52 and 72% versus 87%, P = 0.001), compared with controls. Apart from this, the rate of obstetric complications in group 3 did not differ from the controls. The obstetric history of women in group 1 was marked by higher rates of early miscarriages (26 versus 11%, P = 0.004), gestational diabetes (14 versus 3%, P = 0.02), intrauterine growth restriction (IUGR, 10 versus 1%, P = 0.008), and postpartum haemorrhage than were reported for controls (12 versus 2%, P = 0.01). Conclusion Women who are heteroplasmic for OXPHOS mutations have a higher incidence of pregnancy losses, gestational diabetes, IUGR, and post postpartum haemorrhage. Tweetable abstract Women heteroplasmic for mitochondrial DNA mutations have a higher incidence of obstetric complications, compared with the control group.