Setyaningrum and colleagues recently reported on the management of a pregnant woman with spinal muscular atrophy (SMA) type 3 in the Journal of Medical Case Reports. In this article, we will summarize the salient points of the case study and discuss the challenges of managing a pregnant woman with SMA.
First, a word about the role and purpose of case studies. Personally, from my medical school years, case studies have often helped me translate an abstract concept into something real and living; it provides a foretaste of what to expect when the rubber meets the road. Its usefulness is apparent in that case studies are still used in medical education at all stages of a doctor’s life.
SMA Suspected From a Young Age
This case study comes to us from Indonesia. A 28-year-old woman in the first trimester of her second pregnancy presented with muscle weakness, which was managed in a multidisciplinary antenatal care setting.
In her younger years, SMA was suspected, but her parents decided not to pursue further investigation or treatment due to a lack of funds. From age 12, the patient could no longer walk independently and required the use of a wheelchair for mobility.
As for her first pregnancy, an emergency Cesarean section was performed due to the premature rupture of the membranes. The child was born prematurely at 32 weeks, but was growing healthily, without evidence of muscle weakness.
Read more about SMA etiology
Genetic testing revealed that while her mother has SMA type 3, her first child (a daughter) was merely a carrier. The second pregnancy was initially scheduled for a Cesarean section at 38 weeks of gestational age.
Upon presentation, the woman had severe scoliosis and was unable to walk independently. Flaccid weakness could be observed in all her limbs, with a corresponding reduction in muscle tone and strength.
Neurological tests were promptly conducted. Setyaningrum and colleagues reported, “Electroneuromyography showed an axonal neuropathy of the spinal nerve roots innervating the lower limbs and bilateral median nerves axonopathies without cervical radiculopathy. Electromyography showed a chronic denervation without reinnervation.”
Normally, nusinersen would be administered for such a patient profile. Unfortunately, the authors of the study reported that neither nusinersen nor gene replacement therapy was available at that time. Therefore, the best her physicians could do was to continue her physical and occupational therapy.
The second child, a boy, was delivered at 38 weeks gestational age via an elective Cesarean section. Genetic testing indicated that he too is a carrier. As of the time of publication, there were no reports of muscle weakness concerning SMA or other neuromuscular disorders of concern.
Setyaningrum and colleagues wrote, “This case was . . . the first collaborative case with a multidisciplinary approach between the obstetric, neurology, pediatric, and anesthesiology departments in our hospital.”
Treating SMA Type 3
Let’s take a look at some of the key characteristics of SMA type 3. The first symptoms of all types of SMA are generally muscle weakness, atrophy, and fatigue, starting from the lower limbs and spreading to the upper limbs in an ascending manner. In pediatric patients, parents or guardians might notice difficulties in climbing stairs, jumping, or running. The eventual involvement of the pelvic muscle leads to a characteristic waddling gait, with children complaining of fatigue after walking for short distances.
SMA type 3 differs from types 1 and 2 in that tongue fasciculations are not commonly seen until later stages of the disease. In addition, children with SMA type 3 rarely complain of respiratory muscle distress. Bulbar symptoms are typically absent, and children with SMA type 3 rarely demonstrate learning disabilities (provided that their school has adapted to their needs).
Salort-Campana and Quijano-Roy wrote, “Hypotonia, hyperlaxity and absent osteo-tendinous reflexes are typical features. In addition to weakness, a certain degree of muscle fatigability is observed, as in all forms of SMA, but in SMA3 it is mostly restricted to the limbs.”
Crucially, SMA type 3 patients have a normal life expectancy. On this basis, SMA type 3 is a milder disease compared to SMA types 1 and 2, especially in its early stages.
SMA patients who are pregnant (regardless of type) are considered high-risk pregnancies, as complications including preterm labor, miscarriage, and intrauterine growth restriction can occur.
“Pregnancy in SMA patients should be treated comprehensively and managed carefully,“ Setyaningrum et al wrote. “Maternal factors such as muscle weakness, deformities, and restrictive ventilatory pattern (lung capacity and compliance reductions), as well as social issues such as stigma and concerns from family and environment may arise.”
Read more about SMA treatment
Perhaps the most heartbreaking part of the case presentation was the lack of nusinersen (or comparative therapy) for the patient. This would be a major scandal in the Western world, but in the developing world, issues such as these arise more often than one would care to believe. The problem here of course is defective health policy and funding, for which physicians are not directly responsible. Oftentimes, the best thing to do would be to offer the second-best alternative, which in this case was physical and occupational therapy. No wonder then that morale can be low among the medical community in parts of the developing world.
Another feature of this case study that deserves a mention is that the patient herself was not properly treated for SMA when she was younger due to financial constraints. As Setyaningrum and colleagues explained, “There was no universal national health insurance coverage in Indonesia in the early 2000s.”
The lack of timely care is indeed a tragedy, since the health implications of delayed therapy can be permanent. When reading case reports such as the one detailed here, it is worth reflecting on how different health policies in different countries affect people in different ways, and how the job of a physician in trying circumstances is simply to do the best they can with the tools at their disposal.
Setyaningrum CTS, Harahap ISK, Nurputra DK, Rachman IT, Harahap NIF. Managing pregnancy in a spinal muscular atrophy type III patient in Indonesia: a case report. J Med Case Rep. Published online January 16, 2022. doi:10.1186/s13256-021-03226-1
Salort-Campana E, Quijano-Roy S. Clinical features of spinal muscular atrophy (SMA) type 3 (Kugelberg-Welander disease). Arch Pediatr. 2020;27(7S):7S23-7S28. doi:10.1016/S0929-693X(20)30273-6