Fetal Surgery More Effective than Operating after Birth

February 11, 2011

A UCLA study is the first to systematically evaluate the best treatment for myelomeningocele, the most serious form of spina bifida.

Findings from a groundbreaking study published in the New England Journal of Medicine definitely demonstrate that infants who undergo an operation to repair the birth defect spina bifida while still in the womb develop better and experience fewer neurologic complications than babies who have corrective surgery after birth

The multicenter trial, which was conducted by researchers from University of California, San Francisco CF Medical Center, is the first to systematically evaluate the best treatment for myelomeningocele, the most serious form of spina bifida, in which the bones of the spine do not fully form.

The eight-year trial, which was stopped early because results were so positive, shows that prenatal surgery greatly reduces the need to divert fluid away from the brain, improves mental development and motor function, and increases the likelihood that a child will one day walk unassisted. This is the first time a randomized clinical trial has clearly demonstrated that surgery before birth can improve the outcome for patients.

"For a young couple, finding out their developing child has a problem is one of the most devastating things that can happen. This landmark study offers real hope for improving the lives of children with spina bifida worldwide," said Diana Farmer, MD, the study’s senior author and surgeon-in-chief at UCSF Benioff Children's Hospital. "Based on our findings, it appears that fetal surgery can provide a better option for these patients than waiting to treat them after birth."

Although the Management of Myelomeningocele Study (MOMS) initially aimed to enroll 200 expectant mothers carrying a child with myelomeningocele, it was stopped early in December 2010 with 183 participants because of the significant benefits demonstrated in the children who underwent prenatal surgery.

Spina bifida arises during the first few weeks of development when the neural tube—the embryonic structure that ultimately becomes the central nervous system—fails to close, resulting in an underdeveloped spinal cord, according to co-author Nalin Gupta, MD.

In cases of myelomeningocele, a portion of the spinal cord is left exposed and protrudes through an opening on the baby's back that resembles a cyst. Children with myelomeningocele face lifelong disabilities including leg weakness or paralysis and a loss of bladder and bowel control. They often need braces to walk or are wheelchair-bound.

"I think the outcomes of this trial are game-changing for the field of fetal surgery. However, it is important to remember that fetal surgery is just one of the options available for families and may not be applicable to everyone," Farmer said, noting that there are risks associated with fetal surgery. Infants who underwent the prenatal procedure were more likely to be born preterm, with an average gestational age of 34.1 weeks, compared to an average 37.3 weeks in the postnatal group. Mothers undergoing fetal surgery also face serious risks, and all must deliver subsequent pregnancies by Cesarean section to prevent uterine rupture.

"This is serious surgery, and a woman risks her life just as if she donated a piece of her liver in a living transplant operation,” she said.

According to the authors, continued follow-up of the children in the study is needed to assess whether the early benefits are sustained through school age.

Source: UCSF Medical Center