The Impact of Pregnancy on Myotonic Dystrophy: A Registry-Based Study

Dr. Nicholas Johnson and a research team from the Universities of Utah and Rochester partnered on a study commissioned by MDF to study how women with myotonic dystrophy (DM) are impacted by pregnancy. Data for the study were drawn from the Myotonic Dystrophy Family Registry and the National Registry for DM and FSHD. Previous studies have shown that women with DM may have pregnancy complications in excess of what is normally seen in women without DM. For example, pregnant women with DM1 experience more spontaneous abortions, polyhydramnios (excess amniotic fluid), ectopic pregnancies (fertilized egg implants outside the uterus), placenta previa (placenta covers the cervix) and early labor. Other studies focusing on DM2 showed that 21% of women with DM2 had their first symptom during pregnancy, and women with DM2 experienced more urinary tract infections and preterm labor.

This new study recruited 152 women from the two registries and collected data on their 375 pregnancies. Women with DM1 and DM2 had miscarriage rates of 32% and 37%, respectively, which is higher than the national average of 17%. All women with DM combined had a 10% rate of preeclampsia (high blood pressure and protein in urine) and a 14% rate of peripartum hemorrhage (bleeding before, during or after delivery), both of which are well above the national average of 3%. Many common symptoms of DM progressed during pregnancy, including mobility limitations, activity limitations, pain, emotional issues and myotonia. After delivery many of these symptoms reportedly did not return to the level experienced before pregnancy.

The authors summarize their findings by suggesting that “this research may be utilized by DM patients and family members seeking to better understand the risks and outcomes associated with pregnancy and DM.”


The Impact of Pregnancy on Myotonic Dystrophy: A Registry-Based Study.
Johnson NE, Hung, M, Nasser, E, Hagerman, KA, Chen, W, Ciafaloni, E, and Heatwole, CR.
Journal of Neuromuscular Diseases. Oct 7, 2015.

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