Introduction This study aimed to determine whether an integrated approach, involving training of professional staff in maternity and child health services to deliver sustained brief intervention using Motivational Interviewing (MI) techniques in a standardised way, was sufficient to affect change in smoking status or intensity in low-income pregnant and post-partum women.

Methods 500 consecutive smokers were recruited at the first ante-natal visit to receive usual care (controls). Post staff training, 500 more women were recruited (intervention group). Data were recorded at 28–32 weeks gestation and 3–4 months post-partum. The primary outcome measure was self-reported smoking cessation verified by urinary cotinine. Changes in smoking intensity were also measured.

Results There was no difference in the proportion of those who stopped smoking at 28–32 weeks pregnancy (8.8% vs 9.3%) χ²=5.9, d.f.=3, p=0.12, or 3–4 months post-partum 7.6% vs 7.2% (χ²=4.46, d.f.=3, p=0.21). In late pregnancy cases that had stopped at baseline were more likely to stay stopped (26% vs 42%). More cases who were light (<5 cigs per day) or medium intensity (5–10 per day) smokers at baseline were non-smoking in late pregnancy (light, 21.3% vs 15.8%, medium 6.3% vs 3.1%). At 3–4 months post-partum more cases smoking 5–15 cigarettes per day moved to a lower intensity (83.7% vs 52.1%) and fewer shifted to a higher smoking category.

Conclusion Brief intervention of the intensity offered was ineffective in affecting quit rates in late pregnancy and 3–4 months post-partum. Subtle positive changes around smoking intensity were observed.