Antenatal corticosteroids for fetal lung development
Examples
Generic Name Brand Name betamethasone Celestone Soluspan How It Works
Betamethasone causes an immature fetus's lungs to produce a compound called surfactant. A full-term baby's lungs naturally produce surfactant, which lubricates the lining of the air sacs within the lungs. This allows the inner surfaces of the air sacs to slide against one another without sticking during breathing. Premature infants whose lungs have begun producing surfactant have an improved ability to breathe on their own, or with less respiratory treatment, after birth.
When preterm birth between 24 and 34 weeks of pregnancy (gestation) is expected within 7 days, betamethasone is given to the mother in order to affect the fetus. Betamethasone is given in 2 injections, 24 hours apart.
If delivery does not occur within 7 days of treatment, the injections should not be repeated. Guidelines issued by the U.S. National Institutes of Health discourage such repeat courses of treatment, based on concerns about fetal harm from repeat treatments.1
Why It Is Used
Corticosteroids are considered standard treatment for women who are 24 to 34 weeks pregnant and may deliver within the next 1 to 7 days, with or without preterm premature rupture of membranes (pPROM).1
Betamethasone is a corticosteroid, also called glucocorticoid, that is given before birth (antenatally) to speed up a preterm fetus's lung development. It is used when a mother is in preterm labour and birth may occur in 24 to 48 hours. This helps prevent the occurrence of respiratory distress syndrome (RDS) and related complications following premature birth.
Many infants born at 33 to 34 weeks' gestation have sufficient lung maturity to breathe on their own. However, considering the low-risk, high-benefit nature of this treatment, corticosteroids are typically used up to 34 weeks of pregnancy.
How Well It Works
There is strong evidence that a single course of corticosteroid medication given to the mother during premature labour improves the outcome for the infant born between 24 and 34 weeks' gestation.2
Betamethasone is most effective if delivery occurs at least 24 hours after the first dose of the medication has been given and less than 7 days after the last dose of the medication.
The medication will benefit a premature newborn by decreasing the risk of:
- Breathing problems (respiratory distress syndrome) after birth.
- Bleeding in the brain (intraventricular hemorrhage).
- Intestinal infection (necrotizing enterocolitis).
- Death.
Side Effects
Corticosteroid side effects that might affect the mother can include fluid retention and increased blood pressure. However, they are short-term, and less likely to occur at all during such a short period of treatment. These side effects are more of a concern during long-term treatment for other health problems.
Control of diabetes may be more difficult in pregnant women when corticosteroids are used. If you need insulin, your health professional may recommend a different insulin dose during this time.
See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)
What To Think About
Fetal lung maturity testing (using amniotic fluid collected through amniocentesis) is occasionally used to determine whether antenatal corticosteroid treatment is necessary.
Repeat courses of corticosteroids given before birth are not recommended.1 They may cause long-term effects on the growing child.3
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| Author: | Kathe Gallagher, MSW Carrie Henley | Last Updated: April 10, 2007 |
| Medical Review: | Joy Melnikow, MD, MPH - Family Medicine Anne C. Poinier, MD - Internal Medicine Gregory A L Davies, MD, FRCSC, FACOG - Maternal-Fetal Medicine William Gilbert, MD - Perinatology | |
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| Topic Contents | |
| Examples | |
| How It Works | |
| Why It Is Used | |
| How Well It Works | |
| Side Effects | |
| What To Think About | |
| References | |