Can fetal surgery correct spina bifida before birth?

What does fetal surgery actually accomplish for spina bifida?

The main goal of fetal surgery is to close the opening in the spine before birth, which protects the spinal cord from further damage caused by exposure to amniotic fluid. The most dramatic and consistent effect is the reversal of a condition called hindbrain herniation (Chiari malformation), where brain tissue is pulled down into the spinal canal. In a study of 148 fetuses, 90% had this herniation before surgery, and it completely resolved in 90% of those cases after the procedure [5]. Another study of 46 fetuses found a 70% reduction in hindbrain herniation after surgery (from 100% to 32.6%) [1]. This reversal is critical because it often prevents the need for a separate postnatal surgery to decompress the brain.

Fetal surgery also dramatically lowers the need for a lifelong shunt to drain excess fluid from the brain (hydrocephalus). In the largest fetoscopic study here, involving 103 babies, 53.4% did not require a shunt or similar procedure by 12 months of age [11]. This is a major improvement over the historical rate of over 80% for babies treated after birth. Across multiple studies, the shunt rate after fetal surgery consistently falls between 33% and 41% [3][5][6], showing a clear and reproducible benefit.

For mobility, the results are also encouraging. A study from Zurich reported that 84% of children who had fetal surgery were walking independently by age 3 [5]. A large international study of the fetoscopic SAFER technique found that 54.2% of children were walking independently by 30 months of age [11]. While many children still need orthotics (braces) or walking aids, the ability to walk is far more common than with postnatal care alone.

What are the major risks and trade-offs?

The most significant trade-off is that fetal surgery almost always leads to preterm birth. The average gestational age at delivery across these studies is around 34-35 weeks [2][9][10], which is about 5-6 weeks early. This prematurity carries its own set of risks, including breathing problems and feeding difficulties. In one study, 82% of patients delivered before 37 weeks [2]. Premature rupture of the membranes (the water breaking early) is also very common, occurring in 42% of patients in one large audit [9] and 28% in a pooled analysis of patients with obesity [2].

Maternal risks are a serious consideration. The surgery requires a major operation on the mother, either through a large incision in the uterus (hysterotomy) or a minimally invasive fetoscopic approach. In a study of 100 consecutive cases, severe maternal complications occurred in 7% of women, including anemia, pulmonary edema (fluid in the lungs), and placental abruption [9]. While no maternal deaths were reported in these studies, the risk is real. The surgery also mandates that all future deliveries be by Cesarean section to prevent uterine rupture.

The surgery does not fix all brain abnormalities. A key study found that fetal surgery did not change the proportion of fetuses with an abnormal corpus callosum (the bridge connecting the brain's two halves) or with gray matter heterotopias (misplaced neurons) [1]. Furthermore, the combination of these pre-existing brain anomalies with severe ventriculomegaly (very enlarged brain ventricles) was strongly linked to a 27.7 times higher risk of suboptimal neurodevelopment [1]. This means that while the surgery helps, the underlying brain damage present before surgery can still limit the final outcome.

Open surgery vs. fetoscopic repair: which is better?

There are two main surgical approaches: open fetal surgery, which involves a large incision in the mother's abdomen and uterus (hysterotomy), and fetoscopic surgery, which uses small incisions and a camera. The evidence shows that the fetoscopic approach, when done by experienced teams, can achieve similar neurological outcomes for the baby while causing less trauma to the mother. For example, the large SAFER fetoscopic study reported a 53.4% shunt-free rate at 12 months and 54.2% independent walking at 30 months [11], which is comparable to the best open surgery results [5].

However, the fetoscopic approach is not risk-free. A study comparing a newer 'microneurosurgery' technique (a very small hysterotomy) to the classic open surgery found that the microneurosurgery group had a significantly lower rate of preterm premature rupture of membranes (19% vs. 53.8%), a higher gestational age at birth (35.1 vs. 32.7 weeks), and a lower rate of preterm delivery before 34 weeks (21.4% vs. 61.5%) [8]. This suggests that minimizing the size of the uterine incision, whether through fetoscopy or a mini-hysterotomy, improves pregnancy outcomes. A systematic review confirmed that the least invasive techniques (mini-hysterotomy and microneurosurgery) were associated with better maternal and perinatal outcomes, including a lower risk of preterm delivery [4].

Ultimately, the choice of technique depends on the specific fetal center's expertise and the patient's anatomy. A 2025 global survey found that 76% of centers still use open fetal surgery as their primary method, while 15% use fully percutaneous fetoscopy [7]. The trend is toward less invasive methods, but the most important factor is that the surgery is performed by a high-volume, experienced team.

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This answer is built on 11 peer-reviewed studies — published from 2021 to 2025, 4 from 2024 or later, 6 in Q1 journals, collectively cited 139 times — selected as the most relevant from 14 studies that passed quality screening, drawn from 55 papers retrieved from a database of over 500 million.

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