Objectives: (1) To determine the feasibility of a multicentre, randomized, double-masked, placebo-controlled trial to investigate the effects of multiple courses of antenatal corticosteroids (ACS), more than 7 days following the initial course of ACS therapy, on perinatal or neonatal mortality or neonatal morbidity. (2) To determine the risk of complications that would require discontinuation of ACS therapy. (3) To determine if multiple courses of ACS have an effect on the concentrations of plasma cortisol and adrenocorticotropin hormone (ACTH) in cord blood and in maternal blood immediately following delivery, compared to a single course of ACS.
Methods: Women at 24 to 30 weeks' gestation, at continued increased risk of preterm birth 7 or more days following a single course of ACS, were randomized to receive weekly courses of betamethasone or placebo until 33 weeks' gestation or delivery.
Results: Women were recruited at two hospitals in Toronto from 01 September 1999 to 31 August 2000. Of the 78 women who were approached and were eligible for the study, 12 (15%) were recruited and 66 (85%) refused to participate. Of the 66 refusals, 38 (58%) did not feel their physicians were supportive of the study, 10 (15%) did not want to be randomized, and 4 (6%) had other personal reasons for refusing to enter the trial. Fourteen women (21%) had physicians who did not allow them to join the study. The lack of physician support was due to concerns related to the potential adverse effects of multiple courses of ACS. There were no complications requiring discontinuation of ACS. Plasma cortisol and ACTH concentrations in cord and maternal blood taken after delivery were not significantly different between ACS and placebo groups.
Conclusion: A multicentre randomized controlled trial is required to determine the benefits and risks of multiple versus a single course of ACS. If the study protocols are supported by physicians and their patients, a multicentre randomized controlled trial is feasible.