Objectives: We wished to determine prescribing practices of obstetricians in Canada regarding tocolytics, antenatal corticosteroids, and progesterone for women at increased risk of preterm labour and birth, and to determine whether these practices changed between 1997-98 and 2004.
Methods: Two cross-sectional surveys of Canadian obstetricians were conducted. The initial survey was in 1997-98 (N = 1313); the follow-up survey was in 2004 (N = 1508).
Results: Response rates were 46.4% in 1997-98 and 43.3% in 2004. Most respondents reported that they prescribed tocolytics to women with signs and symptoms of preterm labour (97.4% in 1997-98; 92.2% in 2004; P < 0.001) but use had decreased. In 1997-98, 20.0% of respondents used tocolytics for > 48 hours during one course of treatment, whereas in 2004, only 9.6% did this (P = 0.06). The tocolytic prescribed most frequently was magnesium sulphate in 1997-98 (40.6% of respondents), whereas in 2004, it was indomethacin (47.5% of respondents). The use of repeat courses of antenatal corticosteroids decreased from 72.9% in 1997-98 to 18.7% in 2004 (P < 0.001). In 2004, only a few respondents (7.0%) prescribed progesterone for women at increased risk of preterm birth.
Conclusions: Most Canadian obstetricians continue to use tocolytics for women in preterm labour, although use has decreased over time, and the most frequently prescribed tocolytic has changed from magnesium sulphate to indomethacin. The use of repeat courses of antenatal corticosteroids decreased substantially during this time, and in 2004, progesterone was not in frequent use.