Randomized trial of a “stage-of-change” oriented smoking cessation intervention in infertile and pregnant women

OBJECTIVE: To assess a "stage-of-change" oriented smoking cessation intervention for infertile and pregnant women, compared with standard of care. DESIGN: Randomized controlled trial. SETTING: Three university teaching hospitals in Hamilton, Ontario, Canada. PATIENT(S): Infertile women at their first visit to a tertiary referral infertility clinic (n = 94) and new patients seeking pre-natal care (n = 110) who had smoked >/= 3 cigarettes in the past six months. INTERVENTION(S): A three to five minute scripted intervention and booklet specific to the woman's "stage-of-change" in the smoking continuum, versus standard of care. Exhaled carbon-monoxide (CO) monitoring was used to validate exposure in both groups. MAIN OUTCOME MEASURE(S): Delta "stage-of-change" and rate of maintained cessation at 12 months post follow-up. RESULT(S): Intervention and control were similarly effective for infertile women: the rate of maintained cessation rose significantly from 4% to 24% over twelve months, with a mean delta "stage-of-change" 0.28. In prenatal women, neither approach was effective. Maintained cessation did not significantly change from 0 to 12 months (19% to 18%). Mean delta "stage-of-change" declined by -0.62. CONCLUSION(S): For infertile women, basic information describing the impact of smoking on fertility, along with exhaled CO monitoring and a more intensive intervention were both highly effective. In pregnant women neither approach was beneficial, with some evidence of post-partum relapse.