# Study Overview
A multicentre pragmatic RCT (n=887) in the UK evaluated the BabyBreathe intervention—combining interpersonal support, a resource box, nicotine replacement gum sample, text messages, and a digital app—for maintaining smoking abstinence in pregnant women who quit smoking.
# Primary Results
The primary intention-to-treat (ITT) analysis showed no statistically significant difference in 12-month postpartum abstinence between BabyBreathe and usual care (54.9% vs 49.9%; odds ratio 1.23, 95% CI 0.94–1.60, P=0.13).
# Post hoc Per-Protocol Findings
A post hoc per protocol analysis, restricted to participants who received interpersonal support as intended, favoured the intervention (57.6% vs 49.9%; adjusted odds ratio 1.36, 95% CI 1.02–1.81, P=0.04).
# Key Limitations
- Trial was unblinded, risking performance and detection bias
- Post hoc per protocol analysis was not pre-specified, limiting causal inference
- Intervention fidelity was incomplete; not all participants received interpersonal support as intended
- Generalisability may be limited to UK community health visiting settings
- Socioeconomic subgroup effects were noted but not fully characterised
# Safety
No trial-related adverse incidents occurred.
Quote from the trial: "The group difference in smoking abstinence at 12 months post partum was not significant (BabyBreathe 242/441 (54.9%) v usual care 222/445 (49.9%); odds ratio 1.23, 95% confidence interval (CI) 0.94 to 1.60, P=0.13)."
Authors' suggestion: "A focus on fidelity and further targeting of BabyBreathe to groups with lower socioeconomic status may be warranted."
Abbreviations: ITT=intention-to-treat; aOR=adjusted odds ratio; CO=carbon monoxide