VANCOUVER, B.C. – When there isn’t time for a full course of prenatal steroids before early preterm birth, a partial course is better than nothing, according to investigators at the National Institute of Child Health and Human Development’s Neonatal Research Network.
In a study of 5,248 infants born between 24 and 27 weeks’ gestational age who were alive at 18-22 months, 17.6% (120/683) whose mothers got no prenatal steroids (PNS) before delivery had cerebral palsy, a statistically significant difference from the 13% (178/1,369) whose mothers got one dose of PNS – betamethasone in almost all cases – and the 10.5% (336/3,196) whose mothers got the full course of two betamethasone doses, 24 hours apart.
Dr. Sanjay Chawla
Similarly, intact survival at follow-up – survival free of hearing loss, blindness, and cerebral palsy, plus scores greater than 85 points on the Bayley Scales of Infant and Toddler Development III – was 55% in the no-PNS infants, 65% in the partial-PNS infants, and 69% in the PNS infants who got a full course, all statistically significant differences.
Compared with full-course PNS infants, those who got no PNS (odds ratio, 1.4; 95% confidence interval, 1.2-1.7) or partial PNS (OR, 1.2; 95% CI, 1.1-1.4) were more likely to have died or have neurodevelopmental impairment at 18-22 months.
Earlier results of the study, at discharge, were largely the same, with greater survival and fewer neurodevelopmental impairments when mothers got at least one dose of PNS before delivery.
The reason was that even one dose before delivery helped prevent both brain hemorrhages and cystic periventricular leucomalacia, the investigators found.
Prenatal steroids have long been known to help prevent both problems. What’s new in the findings is confirmation that even one dose helps.
"The intention is always to give a complete course," but when imminent delivery makes that impossible, even "one dose is better than no dose. The results help us counsel parents when we know" what dose children got before delivery. Also, "for research, the question shouldn’t be [prenatal] steroids, yes or no," but the completeness of the course, said lead investigator and neonatologist Sanjay Chawla of the department of pediatrics at the Children’s Hospital of Michigan, Detroit.
"Some people say, ‘She’s going to C-section in an hour, so it doesn’t matter’" That’s wrong. "One shot [of betamethasone] is still better than nothing. It makes a difference," said Dr. Nathalie Maitre, a neonatologist at Vanderbilt University in Nashville, Tenn., who helped moderate Dr. Chawla’s presentation at the Pediatric Academic Societies annual meeting.
There were some significant differences between the groups. No-PNS infants were born a bit earlier, at a mean of 24 weeks instead of about 25 weeks, and were a bit lighter at birth, 690 g instead of almost 800 g in the partial and full PNS groups. They were also a bit more likely to be black and on Medicaid.
Also, partial and full PNS infants were a bit more likely to be born by C-section. Boys and girls were split 50-50 in all three groups.
Dr. Chawla and Dr. Maitre said they had no relevant financial disclosures. The National Institutes of Health funded the work.