Myotonic Dystrophy in Pregnancy

A 28-year-old primigravida currently at 24 weeks gestation attends your high-risk obstetric clinic with her partner. She has recently been diagnosed with myotonic dystrophy and is under the care of a neurologist at your hospital. Her presenting symptoms were progressive muscle weakness and difficulty swallowing over a period of two years. She has had three hospital admissions for aspiration pneumonia, none of which required intensive care unit admission. The pregnancy has been confirmed with an early first trimester ultrasound scan and has been uneventful to date. Observations: Height 1.62 m Weight 65 kg Pulse rate 90 beats per minute Blood pressure 100/60 mmHg Respiratory rate 20 breaths per minute SpO2 96% on room air Airway examination: Thyromental distance less than 5 cm Mallampati class III Inter-incisor distance greater than 4.5 cm Good neck extension Normal jaw protrusion Cardiovascular examination: Normal heart sounds with no additional sounds No signs of heart failure Neurologic examination: Proximal muscle weakness Presence of persistent grip with handshake Mild scoliosis with curvature to left Medications: Bisoprolol 2.5 mg mane Frusemide 20 mg mane A recent transthoracic echocardiogram shows mild biventricular and biatrial dilation; left ventricular ejection fraction 45%; and pulmonary artery systolic pressure of 25 mmHg.