Prenatal myelomeningocele repair improves outcomes

Prenatal surgical repair of myelomeningocele, the most common form of spina bifida, reduces the need for cerebrospinal fluid shunting and improves motor outcomes at 30 months compared with traditional postnatal repair, according to the results of a recent randomized trial conducted at 3 maternal-fetal surgery centers in the United States. Researchers at Children's Hospital of Philadelphia, Pennsylvania, planned to include 200 patients, but the trial was stopped for efficacy after recruitment of 183 women. Results are based on 158 women whose children were evaluated at 1 year.

Only 68% of the infants whose myelomeningocele was repaired before 26 weeks of gestation, versus 98% of those in the postnatal repair group, died (fetal or neonatal) or required shunting by 1 year of age (relative risk [RR], 0.70; 97.7% confidence interval [CI], 0.58–0.84; P<0.001). Forty percent of the prenatal group and 82% of the postnatal group required shunting (RR, 0.48; 97.7% CI, 0.36–0.64; P<0.001). In addition, prenatal surgery resulted in an improved composite score for mental development and motor function at 30 months (P=0.007) and improved secondary outcomes, including hindbrain herniation by 12 months and ambulation by 30 months.

The downside is that prenatal surgery was associated with an increased risk for preterm birth and uterine dehiscence at delivery, compared with postnatal repair. One-third of the women who underwent prenatal surgery had an area of dehiscence or a very thin prenatal uterine scar at delivery. Fetuses treated prenatally were born at an average age of 34.1 weeks, with 13% delivered before 30 weeks' gestation; those in the postnatal repair group were born at an average of 37.3 weeks' gestation. None were delivered before 30 weeks.