LETTER TO EDITOR
|Year : 2012 | Volume
| Issue : 5 | Page : 524--525
Nemaline myopathy and pregnancy: A challenge indeed
Vinotha Thomas, Ruby Jose
Department of Obstetrics and Gynecology, Unit 4, Christian Medical College and Hospital, Vellore, Tamil Nadu, India
Department of Obstetrics and Gynecology, Unit 4, Christian Medical College and Hospital, Vellore, Tamil Nadu
|How to cite this article:|
Thomas V, Jose R. Nemaline myopathy and pregnancy: A challenge indeed.Neurol India 2012;60:524-525
|How to cite this URL:|
Thomas V, Jose R. Nemaline myopathy and pregnancy: A challenge indeed. Neurol India [serial online] 2012 [cited 2022 Jan 25 ];60:524-525
Available from: https://www.neurologyindia.com/text.asp?2012/60/5/524/103207
A 29-year-old woman with nemaline myopathy, the second of four children born to consanguineous parents, with no family history of a similar illness presented at eight weeks of pregnancy for antenatal care. She had delayed motor milestones in childhood and difficulty in walking from two years of age. She had proximal weakness in both the lower limbs and at 13 years of age developed distal weakness in the upper limbs, followed by wasting of all four limbs. She was wheelchair-bound when she presented for antenatal workup.
On examination she had an elongated face with high arched palate, bilateral lower motor seventh and eleventh nerve palsies. There was generalized wasting of limb muscles (distal more than proximal), scapular, neck, and paraspinal muscles and bilateral foot drop. The motor power of limb muscles was 3/5 and handgrip was weak. All deep tendon reflexes were absent. Skeletal deformities included pescavus and kyphoscoliosis. There were bilateral tibialis anterior contractures. Serum creatinine phosphokinase was normal. Quadriceps muscle biopsy had revealed nemaline rods. Echocardiogram was normal. Family history was suggestive of autosomal recessive or sporadic inheritance. Since her partner was non-consanguineous, prenatal diagnosis was not considered.
At eight weeks of gestation, she was diagnosed to have gestational diabetes which was managed with medical nutrition therapy. First-trimester aneuploidy screening was negative for trisomy 21, 18 and 13. At 29 weeks, she was diagnosed to have severe gestational hypertension. Fetal ultrasonogram showed an estimated fetal weight of 949 g (less than the 10 th percentile for gestational age), oligohydramnios and absent end diastolic flow in the umbilical artery doppler. Antihypertensive therapy was started with nifedipine and steroids were administered to hasten fetal lung maturity. In view of the severe gestational hypertension, the decision was made to deliver the baby after discussion with the patient and her husband. Injectable phenytoin 100 mg q8h was used instead of the recommended magnesium sulphate as prophylactic measure against eclampsia, to avoid the theoretical enhancement of magnesium sulphate's neuromuscular blockade action by nifedipine. Following discussion of maternal anesthetic risks, vaginal delivery which posed the least risk was chosen and labor was induced with prostaglandin E 1 50μg, three doses, three hours apart. She delivered a preterm, male baby, weighing 1.06 kg with Apgar of six and seven at one and five minutes respectively, twelve hours after induction. In the postpartum period, blood pressure normalized.
The baby was managed in the neonatal intensive care unit (NICU). He developed non-hemolytic jaundice on the third day of life, which required phototherapy for three days. He was discharged on Day 41 of life, weighing 1.78 kg. Neurosonograms done on Day 7 and 21 were normal. Hearing screening was normal. Retinopathy of prematurity screening showed bilateral immature retina and repeat screen was advised after four weeks.
Nemaline myopathy, a rare, progressive neuromuscular disorder, characterized by muscle weakness, hypotonia and the presence of nemaline bodies (rods) in skeletal muscle is associated with disease-causing mutations in seven genes.  The inheritance can be autosomal dominant or recessive but can occur sporadically. Very few cases of pregnancy, complicating this rare disorder have been reported ,, In such women, multidisciplinary team management is recommended, starting prenatally with genetic counseling, besides determining the severity of restrictive lung disease and ruling out the rare dilated cardiomyopathy. Antenatal diagnosis of fetal nemaline myopathy can be established through chorionic villus sampling, amniocentesis and cordocentesis. Fetal muscle biopsy is unreliable.  Sonological features of congenital nemaline myopathy are polyhydramnios, decreased fetal movements and multiple contractures. Maternal complications include thromboembolism due to decreased mobility, and deterioration in pulmonary function.
Timing and mode of delivery need to be managed individually. Few have had uncomplicated pregnancies and vaginal deliveries.  Fetopelvic disproportion, hip contractures might necessitate caesarean delivery. There have been no reports of postpartum hemorrhage or predisposition to gestational hypertension. Anesthesia consultation prior to surgery is mandatory as these patients might respond abnormally and unpredictably to depolarizing and non-depolarizing muscle relaxants. The high arched palate, prognathic mandible, malocclusion and abnormal facies might complicate laryngeal intubation. Respiratory compromise due to restrictive lung disease, respiratory muscle weakness, chest wall abnormalities, kyphoscoliosis, chronic aspiration and microatelecatasis can lead to ventilation -perfusion mismatch, increased dead space and increased alveolar to arterial oxygen tension gradient. Scoliosis and lordosis pose technical difficulties with regard to regional anesthesia.
Post delivery, women with nemaline myopathy need social support systems for mobilization and care of newborn. Neonatal assessment by a pediatric neurologist and periodic follow-up can pick up inheritance of the disease.
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