NEW YORK (Reuters Health) – At 18 to 24 months of age, the children of women at high risk for preterm birth who were given several courses of prenatal corticosteroids have not fared any better or worse than those whose mothers received placebo.

Those 2-year outcome results from the Multiple Courses of Antenatal Corticosteroids for Preterm Birth Study (MACS) are reported in the November issue of Pediatrics, published online October 18, by Dr. Elizabeth V. Asztalos with Sunnybrook Health Sciences Centre in Toronto, Ontario, and colleagues elsewhere in Canada.

“Since the MACS trial and its 2-year follow-up showed no significant difference, our recommendation is still not to consider repeated courses for women at risk of preterm birth as it shows no benefit to the infant and child, and harm has not been totally ruled out,” Dr. Asztalos advised in emailed comments.

The trial enrolled women between 25 and 32 weeks gestation who were at high risk of preterm birth. They were randomized to receive a course of prenatal corticosteroids or placebo. Those who remained pregnant after the initial course received repeated courses every 14 days until week 33 or delivery.

The current study reviews outcomes in 2104 offspring. Rates of neurologic impairment or death were 13.8% and 13.7% in the corticosteroid and placebo groups, respectively.

Neurodevelopment and cognitive assessment at a median age of 22 months in 2008 surviving offspring — 1020 in the prenatal corticosteroid group and 988 in the placebo group — showed no difference in mean scores in the two groups. For example, the mean Mental Development Index was 93.91 in the corticosteroid group and 94.74 in the placebo group.

Physically the two groups were similar too. Those exposed to prenatal corticosteroids “had a mean weight of 11.94 kg, compared with 12.14 kg in the placebo group (p=0.04), a mean height of 85.51 cm, compared with 85.46 cm (p=0.87), and a mean head circumference of 48.18 cm, compared with 48.25 cm (p=0 .45),” according to the report.

“Although we could not see any evidence of obvious harm at 2 years of age, we could not determine that harm is still not evident,” Dr. Asztalos pointed out.

She continued, “Animal studies on steroid exposure suggest the brain as a very vulnerable organ and may be subjected to aberrations in development during fetal life that may not manifest itself until a child is older. These aberrations may have an effect more on other components of development in a child such as behavior, attention and learning challenges. These elements are not very easily and reliably measured in the child before 2 years of age unless it is grossly obvious.”

Further follow-up studies are therefore planned. “More subtle changes become apparent as the child is approaching school age and these skills become more necessary in day-to-day functioning. Hence the ongoing need to assess children at an older age, which is currently underway with the 5-year-old follow-up,” Dr. Asztalos concluded.

Reference:

Multiple Courses of Antenatal Corticosteroids for Preterm Birth Study: 2-Year Outcomes

Pediatrics 2010.