Obstetric risk in patients with myopathy due to MATR3 mutations

The obstetric risk associated with myopathy due to MATR3 mutations is unknown.

Eight women with the MATR3 p.S85C mutation were recruited. Information on pregnancy, outcome, and effect on muscular function was analysed retrospectively using a pregnancy and delivery questionnaire. The data were compared with information from the German perinatal quality survey.

All eight women responded. Their muscular symptoms started between the ages of 36 and 56. Sixteen pregnancies and twelve deliveries could be analysed. Two women had a voluntary abortion after their deliveries for other medical reasons. One woman reported a miscarriage in the first trimester. Five women had pregnancies and deliveries without complications. One woman twice had labour weakness requiring forceps delivery. Another patient twice had a preterm dilatation of the cervical os and forceps deliveries. One of her children had foetal distress and was born preterm and with low birth weight. No perinatal childhood death was reported. No women described muscular symptoms before or during their pregnancies.

Pregnancies in matrin 3 myopathy typically occur several years before the onset of myopathy. No increase in the incidence of foetal distress or miscarriage was found. However, late pregnancies (e.g. in the 5th decade) should be regarded as pregnancies at risk.