Feb. 3, 2000 (Miami) -- A form of fetal surgery to correct the disabling birth defect called spina bifida is also associated with an accelerated head growth, according to Danielle S. Walsh, MD, speaking here at a meeting of maternal-fetal medicine specialists.
The findings suggest that the surgery prevents some of the damage associated with this defect, says Walsh, a fellow in maternal-fetal medicine at Children's Hospital of Philadelphia.
Spina bifida is a neural tube defect that prevents the spine from developing properly. While it can leave a baby with clubbed feet, no bladder or bowel control, or brain damage, it can also be detected preterm. The fetal surgery designed to correct it actually takes place while the fetus is still in the mother's womb.
When a fetus has spina bifida, the head circumference is often disproportionately small. Walsh and her colleagues measured several components of head growth in nine fetuses in order to determine whether the increase was due to actual brain growth or to an accumulation of fluid due to spina bifida. The fetuses with spina bifida were compared to normal fetuses same stage of development.
Prior to surgery, all of the affected fetuses had smaller head circumferences than is typical. They underwent meningomyelocele (MMC) repair, where the spinal column defect is closed.
At 30 days after surgery, seven of the nine fetuses had improved head circumferences. "Average increase in [head circumference] was 25.3% for the [spina bifida] group and 17% for the [normal fetuses]," says Walsh. Other components of head growth were similar to those in the normal fetuses. The study's results suggest that the postoperative increase is due to brain growth rather than ongoing problems related to spina bifida, she says.
"Surgical repair of spina bifida represents a jump in surgical fetal therapy, which has been previously limited to life-and-death circumstances," Mark I. Evans, MD, tells WebMD in an independent interview. "This repair is an attempt to enhance quality of life." Because the patients who have undergone this surgery are so young, it is unknown where other aspects of spina bifida can be corrected, such as motor function in the legs.
However, head growth is an important benefit, says Evans, the Charlotte B. Failing Professor of obstetrics and gynecology and professor of molecular biology and genetics at Wayne State University in Detroit.
When expectant parents get a prenatal diagnosis of spina bifida, they are typically vulnerable and grasping for hope, Ronald J. Wapner, MD, the session moderator, tells WebMD. Therefore, they need to be completely informed about any investigative therapies they are considering.
"We've tested techniques that were ... feasible, only to find that [they] didn't alter the disease," says Wapner, the director of maternal-fetal medicine and reproductive genetics at Thomas Jefferson University in Philadelphia. "[Physicians] have to be especially careful that we're certain that what we're offering has benefit. The bottom line for women is to get as many opinions as they can and make their own decisions."