Early C-section helped baby with SMA begin her treatment right away
Case report shows baby hit typical motor milestones at 10 months
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- Planned late-preterm C-section may help babies with SMA start treatment sooner.
- Motor neuron loss in some severe SMA cases may begin before birth.
- In the case report, a baby treated soon after birth met milestones at 10 months.
For babies diagnosed with spinal muscular atrophy (SMA) before birth, doctors may be able to plan an early delivery so the baby can start treatment within days instead of waiting for a full-term birth.
In a new case report, doctors used this approach for a baby girl with SMA. At her latest follow-up, she was 10 months old and meeting typical motor milestones. The report, “Elective Preterm Birth for Earlier Spinal Muscular Atrophy Treatment,” was published in Molecular Therapy Advances.
SMA is a genetic disease caused by low levels of SMN protein. Without enough SMN, motor neurons — the nerve cells that control movement — can become damaged and die, leading to SMA symptoms such as muscle weakness.
New SMA medicines help protect motor neurons
Over the past decade, several disease-modifying therapies for SMA have become available in the U.S. and many other countries. These include Spinraza (nusinersen), an injection; Evrysdi (risdiplam), an oral medication; and one-time gene therapies Zolgensma (onasemnogene abeparvovec-xioi) and Itvisma (onasemnogene abeparvovec-brve). All aim to boost SMN protein levels, helping protect motor neurons.
In clinical studies, these SMN-boosting therapies have been shown to slow disease progression. But they generally cannot restore motor neurons that have already been lost, which is why treatment tends to work best when started as early as possible.
In this report, doctors in Belgium and the U.K. described a family with two children affected by SMA. Their first child was diagnosed with SMA through newborn screening and started treatment at 18 days old. Even so, by 20 months, the child had a “motor deficit,” the researchers wrote, without providing more details.
Because of the family history, doctors tested the second pregnancy and found that the fetus also had SMA.
The authors noted that in more severe types of SMA, motor neuron loss may begin before birth, including during the third trimester. This is one reason they argued that starting treatment as early as possible, sometimes within the first days of life, may be especially important.
Doctors deliver baby early to start therapy sooner
Given these concerns, and after extensive consultations with specialists, the parents chose an elective cesarean section to deliver their baby at 35 weeks and four days of pregnancy. A typical pregnancy lasts about 40 weeks, and birth before 37 weeks is considered preterm. The goal was to start SMA treatment within days after birth, rather than waiting several more weeks for a full-term delivery.
The baby started taking oral Evrysdi on day two of life and received one-time treatment with Zolgensma on day 59. Her motor development was largely typical, though between 2 and 4 months she had a temporary loss of head control that later improved. By her most recent follow-up at 10 months, she was meeting expected motor milestones, including crawling and standing with support.
The researchers said that longer follow-up is still needed. Even so, they said the case supports the feasibility of planned late-preterm delivery as one way to help babies with SMA begin treatment soon after birth.
Report highlights growing push for earlier SMA diagnosis and care
This case report adds to a growing interest in starting SMA therapy as early as possible. In another published report, a mother began taking Evrysdi during pregnancy in an effort to treat SMA before birth, since the oral medicine can cross the placenta.
The authors noted that starting treatment during pregnancy still comes with challenges, including the lack of regulatory clearance and possible insurance barriers. By contrast, they wrote that planned delivery early, like the approach used here, “offers a pragmatic and potentially safer alternative when prenatal diagnosis is established,” while also emphasizing that preterm birth “introduces its own risks.”
Overall, the researchers called for more data on how early treatment affects long-term outcomes for babies born with SMA in the modern treatment era.
