Preterm birth is a global problem, with about 15 million babies born preterm each year. Respiratory distress remains one of the most common and serious
problems we see in the delivery room that can cause infant mortality.
Currently, corticosteroids are recommended for women at high risk of
preterm birth between 23 and 33 weeks of pregnancy, but not after.
‘A single course of steroids may be useful in reducing lung complications in women at high risk for preterm birth at 34-37 weeks, or for women undergoing a planned C-section at or after 37 weeks.’
meta-analysis compiling evidence from six clinical trials confirms
earlier work suggesting that at-risk babies may benefit from steroids
after 34 weeks and suggests that babies born to mothers who had a
scheduled cesarean section after 37 weeks may benefit as well.
was published in The BMJ
Dr. Vincenzo Berghella, Director of Maternal Fetal Medicine at
the Sidney Kimmel Medical College at Thomas Jefferson University and co-author Gabriele Saccone, at the
University of Naples Federico II, compiled data from three previously
completed double-blind clinical trials, including 3,200 women at between
34 to nearly 37 weeks of pregnancy and at imminent risk of preterm
Babies born in this window are less likely to have fully matured
lungs (incidence of respiratory distress syndrome was 6.7%
without steroids, and 2.7% with steroids).
The researchers also included data from three trials of 2,498 women
who had a scheduled C-section at 37 weeks or older. Infants delivered by
C-section are also more likely to have respiratory distress because the
natural birthing process stimulates the final stages of lung
It is thought that labor contractions and the pressure of
going through the birth canal cause a baby's lungs to expel amniotic
fluid and begin producing the surfactants that lubricate the lungs and
make it possible to start breathing air. The incidence of severe
respiratory distress in this group was 2.3% without steroids and
1.4% with steroids.
The authors conclude that a single course of steroids (two shots
over 24 hours) may be useful in reducing lung complications in women at
high risk for preterm birth at 34-37 weeks, or for women undergoing a
planned C-section at or after 37 weeks.
However, the meta-analysis also revealed a risk of corticosteroid
administration in this group: there was a higher likelihood of
hypoglycemia, or low blood sugar, in infants whose mothers were treated.
The clinical significance of neonatal hypoglycemia in these babies is
not well known, as these babies did not seem to have any short-term
consequences from the hypoglycemia, and there are not yet any data on
their long-term outcome.