Systematic review of 127 studies shows psychosocial interventions improve smoking cessation in pregnancy.

Rationale Tobacco smoking is a leading preventable cause of pregnancy complications with serious long‐term impacts on women and babies. This update is needed to incorporate new evidence and ensure that guidance on psychosocial interventions in pregnancy remains current for policy and practice. Objectives To assess the effects of psychosocial interventions provided to support pregnant women who are currently smoking or have recently quit, on smoking abstinence, continued postpartum abstinence, and infant outcomes. Search methods We searched Embase, MEDLINE, PsycINFO, four other databases and two trial registers, together with reference checking, citation searching, and contact with study authors to identify studies that are included in the review. The latest search date was November 2025. Eligibility criteria We included randomized controlled trials, cluster‐randomized trials, and quasi‐randomized controlled trials in pregnant women who smoked cigarettes or have recently quit, comparing psychosocial interventions (counseling, health education, feedback, social support, incentives, exercise) with usual care, less intensive interventions, or alternative interventions. We excluded studies on other forms of tobacco (e‐cigarettes, smokeless tobacco), environmental tobacco smoke exposure, and those aimed outside of pregnancy (e.g. postpartum interventions). Outcomes The critical outcome was self‐reported and/or biochemically validated smoking abstinence in late pregnancy. The important outcomes included: smoking abstinence from zero to five months postpartum; mean birthweight; low birthweight (< 2500 g); preterm births (< 37 weeks); stillbirths; and neonatal intensive care unit (NICU) admissions. Risk of bias We used the Cochrane Risk of Bias tool 1. Synthesis methods We synthesized results for each outcome using random‐effects meta‐analysis where possible. Where this was not possible, we have presented narrative summaries. We used GRADE to assess the certainty of evidence for main outcomes, including smoking abstinence in late pregnancy, low birthweight, preterm birth, mean birthweight, stillbirth, and NICU admissions. Included studies We included 127 studies (including 145 study arms) with 47,361 participants. Synthesis of results Smoking abstinence during late pregnancy All psychosocial interventions, compared with all comparator types, probably result in an important increase in the likelihood of smoking abstinence during late pregnancy (RR 1.41, 95% CI 1.30 to 1.54; I² = 47%; 117 studies, 33,694 participants; moderate‐certainty evidence) and in the early postpartum period (0 to five months) (RR 1.33, 95% CI 1.18 to 1.50; I² = 28%; 42 studies, 11,977 participants; moderate‐certainty evidence). Similar effects were observed for counseling compared to usual care (RR 1.51, 95% CI 1.26 to 1.82; I² = 51%; 32 studies, 12,920 participants; moderate‐certainty evidence) and financial incentives compared to alternative interventions (RR 2.03, 95% CI 1.38 to 2.98; I² = 58%; 7 studies, 1837 participants; moderate‐certainty evidence). Health education compared with usual care may result in an important increase in the likelihood of smoking abstinence during late pregnancy (RR 1.62, 95% CI 1.22 to 2.14; I² = 0%; 10 studies, 2137 participants; low‐certainty evidence). Similar effects were observed for feedback compared to usual care (RR 2.17, 95% CI 0.79 to 5.92; I² = 54%; 4 studies, 442 participants; low‐certainty evidence) and social support compared to less intensive interventions (RR 1.21, 95% CI 0.93 to 1.58; I² = 0%; 7 studies, 781 participants; low‐certainty evidence). Exercise compared to usual care probably results in little to no difference in the likelihood of smoking abstinence during late pregnancy (RR 1.20, 95% CI 0.72 to 2.01; 1 study, 785 participants; moderate‐certainty evidence) and the evidence was very uncertain about the effect of active compared to passive dissemination of a smoking cessation on the likelihood of smoking abstinence during late pregnancy (RR 1.63, 95% CI 0.62 to 4.32; 1 study, 194 participants; very low‐certainty evidence). Infant outcomes All psychosocial interventions, compared with all comparator types, may result in an important increase in the mean birthweight of infants (MD 56.90, 95% CI 35.30 to 78.51; I² = 22%; 31 studies, 13,726 participants; low‐certainty evidence) and an important decrease in the likelihood of infants born with low birthweight (< 2500 g) (RR 0.82, 95% CI 0.73 to 0.94; I² = 0%; 20 studies, 10,190 participants; low‐certainty evidence). The evidence was very uncertain about the effect of psychosocial interventions compared with all comparators on the likelihood of preterm births (RR 0.96, 95% CI 0.82 to 1.13; I² = 21%; 23 studies, 11,580 participants; very low‐certainty evidence). There is probably little to no difference between psychosocial interventions and all comparators in the likelihood of stillbirth (RR 1.11, 95% CI 0.72 to 1.73; I² = 0%; 10 studies, 7481 participants; moderate‐certainty evidence). All psychosocial interventions, compared with all comparators, may result in an important decrease in the likelihood of infants being admitted to the NICU immediately after birth (RR 0.84, 95% CI 0.70 to 1.01; I² = 0%; 12 studies, 3584 participants; low‐certainty evidence). Health equity Half of the studies included women from disadvantaged backgrounds, including 11 studies involving ethnic minorities and four involving indigenous communities. Few studies examined whether intervention effects differed across population groups, leaving insufficient evidence to determine how interventions might be tailored to improve effectiveness in priority populations. Certainty of evidence Our confidence in the evidence is limited due to study limitations and imprecision. Several studies were unclear regarding random sequence generation and allocation concealment. For some outcomes, the 95% confidence intervals crossed our thresholds for important effects, leading to downgrading for imprecision. Authors' conclusions Counseling and financial incentives probably support women to stop smoking, while health education, feedback, and social support may support women to stop smoking in late pregnancy, by an amount likely to be important. Psychosocial interventions may also reduce the proportion of infants born with low birthweight, increase mean birthweight, and reduce the number of infants admitted to NICU. These findings were not evident in ethnic minority or Indigenous populations. Funding This Cochrane review was funded (partly) by the 2021 MRFF Maternal Health and Healthy Lifestyles (2022138), NHMRC Leadership Fellowship (GNT2025437), and NHMRC Investigator Grant (GNT2009612). Registration Protocol (1998) https://doi.org/10.1002/14651858.CD001055 Original review (1999) DOI: 10.1002/14651858.CD001055 (this first version of the review is not available in the Cochrane Library) Review update (2004) https://doi.org/10.1002/14651858.CD001055.pub2 Review update (2009) https://doi.org/10.1002/14651858.CD001055.pub3 Review update (2013) https://doi.org/10.1002/14651858.CD001055.pub4 Review update (2017) https://doi.org/10.1002/14651858.CD001055.pub5 PICOs PICOs Population Intervention Comparison Outcome