Operations to repair a common birth defect of the spine are more beneficial when they are performed before children are born, improving infants’ health and chances of walking unaided, a U.S.-funded study shows.
The condition, spina bifida, each year affects about 1,500 newborn babies. Standard treatment until now has been to operate after birth to close the defective opening in the spine and drain excess fluid from the brain. By then, permanent damage has been caused by the leakage of spinal fluid, friction on the spinal cord and its exposure to amniotic fluid, doctors say.
The study results, released today by the New England Journal of Medicine, give parents another option. Children who underwent the surgery in utero rather than after birth were more likely to walk, had better motor function and were less likely to need a shunt to drain fluid from the brain 2.5 years after treatment. The biggest drawback of fetal surgery was premature birth, which occurred in 79 percent of cases.
“The benefits are incontrovertible, the results are striking and some of the kids are just amazing,” said N. Scott Adzick, the lead researcher, who is surgeon-in-chief at Children’s Hospital of Philadelphia and director of its center for fetal diagnosis and treatment. “Prenatal repair was better in almost every regard than repair after birth.”
The surgery isn’t a cure, Adzick said in a telephone interview. Some children got little or no improvement from the fetal surgery, while overall those getting early treatment fared better, he said.
Trial Halted on Benefits
The study involved 183 surgeries conducted at the Philadelphia hospital, at the University of California, San Francisco, and at Vanderbilt University in Nashville, Tennessee. The trial was halted by independent monitors in December because of the benefits.
The prenatal surgery was done after 19 weeks to 26 weeks of pregnancy, called gestation, because studies have shown that later operations offer no benefit. Cesarean sections were performed at 37 weeks on women who didn’t undergo early surgery, and their infants were treated within 24 hours of birth.
After one year, 40 percent of children in the prenatal surgery group needed a shunt to drain spinal fluid, compared with 82 percent of those getting later treatment. After 2.5 years, those who underwent the fetal surgery had better mental and motor function development, the study found.
“The outcomes are game-changing for the field of fetal surgery,” said Diana Farmer, the study’s senior author and surgeon-in-chief at UCSF’s Children’s Hospital. “It appears that fetal surgery can provide a better option for these patients than waiting to treat them after birth.”
None of the mothers in the study died. One-third of those who underwent fetal surgery had thin scars at the surgery site, making later pregnancies more dangerous. They were also more likely to have spontaneous membrane rupture or too little amniotic fluid. Their infants were born after an average of 34 weeks of gestation compared with 37 weeks for babies treated after birth.
The study was funded by the National Institute of Child Health and Human Development, based in Bethesda, Maryland.
It’s not clear whether the benefits of prenatal surgery will extend to all children with spina bifida, wrote Joe Leigh Simpson from the departments of genetics and obstetrics at Florida International University in Miami and Michael Green, from Massachusetts General Hospital in Boston. Success rates may be lower for treatment programs with less experience, the said.
“It is human nature to overestimate the likely benefit for one’s own fetus and to underestimate the associated risks,” they wrote in an editorial accompanying the study. The study “is a major step in the right direction, but the still suboptimal rates of poor neonatal outcome and the high maternal risk necessitate the use of less invasive approaches.”
People with spina bifida have medical challenges caused by the condition, including paralysis, bladder and bowel problems, excess fluid on the brain and mental deficits.
While the study has followed most children for only a few years, the results for those who underwent prenatal surgery previously showed the promise of the technique, doctors said.
Shannon Southway, now 37, underwent fetal surgery almost a decade ago to treat her unborn son with spina bifida. Her 9- year-old son Colin, a fourth-grader at an elementary school in suburban Detroit, can run, jump and play unaided.
“Colin’s results are phenomenal, his mobility and quality of life,” Southway said. “He’s a testament to what the surgery can accomplish. He does have a birth defect and some medical issues that we tend to, but they are nowhere near what our prognosis led us to believe his life would be like.”
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