The average pregnancy lasts about 40 weeks, with some studies indicating that pregnancy lengths have actually gotten longer. A term pregnancy is defined as a pregnancy at 37 weeks. Infants born as early as 22 weeks and a few even earlier are surviving with much medical care and hospitalization. With the emphasis on saving these little lives, the longer a baby stays in the uterus the better its chances are of surviving and reducing complications after birth. It has generally been accepted that infants born slightly premature are not in as much danger.
Recent studies say that this is simply not true. Even slightly premature infants (34 - 36 weeks gestation) are at increased risks of certain complications after birth and suffer 2-3 times the infant mortality rate during the first year as their term cohorts. Infants born between 32-33 weeks had a six fold increase in death rates during the first year.
The study, published in the Journal of the American Medical Association, is really talking to the use of induction, particularly for convenience, in these slightly premature infants, calling into question the benefits versus risks of early induction or scheduled cesarean.
Steroid Injection for Fetal Lung Development
Injections of corticosteroids for fetal lung development has been praised as one of the best advances in fetal medicine in the 90s. Since 1994 the National Institutes for Health and other professional organizations have encouraged their use in promoting the development of fetal lung development in moms who were at risk for preterm labor or birth.
Betamethasone and dexamethasone are the two most commonly used steroids. The average protocol was to give to intramuscular injections (IM) 24 hours apart. Some practitioners also choose to continually repeat the dosages every week until the birth. The injections had to be given 24-48 hours prior to the birth for maximum effect. They were also best used between weeks 24 and 34 gestation.
The use of the steroids provided benefits for the lung development in the premature infants to reduce the risk of respiratory distress syndrome (RDS) as well as to reduce the risk of intracranial hemorrhaging and some other potential benefits.
However, recent studies say that the benefits of multiple doses is questionable, particularly in light of potential risks. Citing the "limited quality" of the studies of multiple doses and the potential disadvantages the National Institute of Health issued a statement of August 18th that a single dose was sufficient in achieving the benefits desired.
Potential down sides to multiple doses can include: psychomotor delays, behavioral problems and the fact that the effects on neonatal mortality aren't known between the single and multiple dose courses. In separate findings by an Israeli study it was also noted that there is an increase in maternal infection with the use of steroids, so limiting doses may help with this side effect as well.