Updated 7/8/00
High doses of corticosteroids like Betamethasone often are given by injection to pregnant women experiencing preterm labor or who have pre-eclampsia and may need to be delivered early. Controlled studies have shown that a single course (two 12 mg shots with a long lasting agent) of corticosteroids helps mature the baby's lungs and reduces the incidence of respiratory distress syndrome (RDS). RDS can be a fatal condition in preemies. Steroids also lessen the risk of intraventricular hemorrhage, another life-threatening preemie complication. In 1994, the National Institutes of Health endorsed the use of these steroids for cases of threatened preterm labor between 24 and 34 weeks gestation. The risks to pregnant women who take these steroids were lightly discussed. The severity of the potential complications was not addressed. For example, steroids often are given in combination with preterm labor drugs. The risk of a life-threatening complication called pulmonary edema increases when steroids and terbutaline are used together. Other studies have found an increased incidence of gestational diabetes among women who take the steroid-terbutaline combination. Still other studies, not mentioned by the NIH, have linked the combination of steroids and terbutaline (and other beta-adrenergics like it) to cardiovascular complications. Furthermore, the NIH made a blanket recommendation that steroids be used for all fetuses between 24 and 34 weeks gestation when preterm labor occurs. However, there were several areas of uncertainty when this recommendation was made. These areas include:
1. Do steroids work in multiple gestations? The evidence is mixed, but some studies show steroids *do not* prevent RDS in multiple gestations. In fact, in one study involving women pregnant with triplets or quadruplets, the administration of steroids increased the chances that the women would go into labor. In addition, women pregnant with multiples face a higher risk of complications from steroids and preterm labor drugs.
2. Are multiple courses of steroids safe and effective? Most of the controlled studies were done with a single course (2 shots) of steroids. The protective effect of these shots are supposed to last about 7 days. However, women who go into preterm labor early in their pregnancy may receive many weeks of these shots. The safety of these repeated courses has not established, according to NIH's Consensus Statement. A retrospective1999 study found that women exposed to multiple courses of steroids had more infectious diseases than those women who did not (64.8% vs. 17.5%). Some of these infections were serious and potentially life-threatening. They included sepsis and pneumonia. The study authors say high doses of steroids are known to make patients more vulnerable to life-threatening bacterial, viral, fungal and parasitic agents. A high dose was defined as more than the equivalent of 10 mg of prednisone a day or 700 mg per week. Because of the long-lasting component in the betamethasone pregnant women receive, their equivalent dose in prednistone is 60-80 mg per day and a maximum cumulative dose of 3600-4200 mg of prednistone. This is just for *one course* of betamethasone. Women who receive many weeks of betamethasone shots obviously are exposed to even higher levels of these steroids.
Another retrospective study that compared multiple (greater than 2) to single courses of steroids in found that multiple courses of steroids were associated with a reduction in birth head circumference in preterm infants. Multiple courses of steroids also were associated with an increased incidence of endometritis (inflamation of the lining of the uterus) in the women who took them. Despite these side effects, the multiple course of steroids was associated with a lower incidence of RDS (35%) than the single course (45%).
References
"Effect of Corticosteroids for Fetal Maturity on Perinatal Outcomes," NIH Consensus Statement, Vol. 12, No. 2, February 28-March 2, 1994.
Abbasi, Soraya, et al., "Effect of Single versus Multiple Courses of Antenatal Corticosteroids on Maternal and Neonatal Outcome," American J. of Obstetrics and Gynecology 2000, Vol. 182, pp. 1243-9.
Elliott, John P. And Radin, Tari, "The Effect of Corticosteroid Administration on Uterine Activity and Preterm Labor in High-Order Multiple Gestations, " Obstetrics and Gynecology 1995, Vol. 85, pp. 250-4.
Fisher, Jay E. et al., "Gestational Diabetes Mellitus in Women Receiving Beta-Adrenergics and Corticosteroids for Threatened Preterm Delivery," Obstetrics and Gynecology 1997, Vol. 90, pp. 880-3.
Quist-Therson, Emmanuel C., et al., "Antenatal Steroids to Prevent Respiratory Distress Syndrome: Multiple Gestation as an Effect Modifier," Acta Obstet Gynecol Scan 1999, Vol. 78, pp. 388-392.
Rotmensch, Siegfried, et al., "Maternal Infectious Morbidity Following Multiple Courses of Betamethasone," Journal of Infection, 1999, Vol. 39, pp. 49-54.
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