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Double-blind, randomised, placebo-controlled trial of Nicotine Replacement Therapy (NRT) in pregnancy - SNAP
DOI 10.1186/ISRCTN07249128
ClinicalTrials.gov identifier
EudraCT number
Public title Double-blind, randomised, placebo-controlled trial of Nicotine Replacement Therapy (NRT) in pregnancy - SNAP
Scientific title
Acronym SNAP
Serial number at source HTA 06/07/01
Study hypothesis 1. To compare at delivery: the effectiveness and cost effectiveness for achieving biochemically-validated smoking cessation of nicotine replacement therapy and placebo patches in pregnancy
2. To compare at two years after delivery: the effects of maternal nicotine replacement therapy and placebo patch use in pregnancy on behaviour and cognitive development in children

Please note that, as of 11/05/2009, the anticipated end date has been updated from 31/01/2012 to 30/11/2012.
Lay summary Not provided at time of registration
Ethics approval Ethical approval to conduct this study from the Oxfordshire REC A ethics committee (ID number 04/Q1604/85).
Study design Randomised controlled trial
Countries of recruitment United Kingdom
Disease/condition/study domain Pregnancy/Childbirth
Participants - inclusion criteria 1. Eligible women are women between 12 and 24 weeks pregnant
2. Report smoking at least ten cigarettes daily before pregnancy
3. Still currently smoke at least five cigarettes daily
4. An exhaled Carbon Monoxide (CO) reading above 8 ppm
Participants - exclusion criteria Women with the following contraindications to the use of NRT will be excluded:
1. Severe cardiovascular disease
2. Unstable angina
3. Cardiac arrhythmias
4. Recent cerebrovascular accident or Transient Ischaemic Attack (TIA)
5. Chronic generalised skin disorders or known sensitivity to nicotine patches
6. Chemical dependence/alcohol addiction problems
7. Women who cannot give informed consent and those with known major foetal anomalies will also be excluded

Intra-Uterine Growth Restriction (IUGR) is not an exclusion criterion.
Anticipated start date 01/02/2006
Anticipated end date 30/11/2012
Status of trial Completed
Patient information material Not available in web format, please use the contact details below to request a patient information sheet
Target number of participants 1050
Interventions Treatment group:
Pregnant women will receive an eight week course of 15 mg/16 hour NRT transdermal patches. Although many studies have used longer courses, there is no evidence that these are more effective. Patches will be issued in conjunction with individual behavioural support which is an effective smoking cessation intervention in pregnancy. Four weeks after their quit dates, women who are not smoking will be issued with a second four week supply of patches.

Control group:
Women in the control arm of the trial will receive an identical placebo NRT patch and the same behavioural support as those in the treatment group.

In both control and intervention groups, participants will be blind to their group allocation.
Primary outcome measure(s) Self-reported, prolonged and total abstinence from smoking or the use of any non-pharmacological nicotine containing substances between a quit date set within two weeks of randomisation and immediately prior to childbirth.

Prolonged abstinence cannot be comprehensively validated, but if participants report prolonged abstinence and are abstinent at both time points below, they will be considered to have a positive primary outcome:
1. Self reported smoking cessation for at least 24 hours before follow-up at one month after quit date, validated by exhaled Carbon Monoxide measurement
2. Self reported smoking cessation for at least 24 hours before hospital admission for childbirth, validated by exhaled Carbon Monoxide or salivary cotinine measurement
Secondary outcome measure(s) 1. Smoking:
1.1. Self reported, prolonged abstinence from smoking between quit date and one month
1.2. Self reported, prolonged abstinence from smoking between quit date and 6 months after delivery
1.3. Self reported smoking cessation for previous 7 day period at 6 months after delivery (point prevalence)
1.4. Self reported, prolonged abstinence from smoking between quit date and 2 years after delivery
1.5. Self reported smoking cessation for previous 7 day period at 2 years after delivery (point prevalence)
2. Foetal loss and morbidity:
2.1. Foetal death and stillbirth
2.2. Neonatal death (i.e. from birth to 28 days)
2.3. Post-neonatal death (29 days to 2 years)
2.4. Individualised birth weight Z score (i.e. birth weight adjust for gestational age, maternal height, maternal weight at booking and ethnic group)
2.5. Apgar score
2.6. Cord blood pH
2.7. Gestational age at birth
2.8. Intraventricular haemorrhage
2.9. Neonatal enterocolitis
2.10. Neonatal convulsions
2.11. Congenital abnormality
3. Maternal morbidity and mortality:
3.1. Maternal mortality
3.2. Mode of delivery
3.3. Proteinuria
3.4. Hypertension in pregnancy
4. Early childhood outcomes:
4.1. Behaviour and development at 2 years
4.2. Disability at 2 years
4.3. Respiratory symptoms at 2 years
5. Health economic data:
5.1. Duration of maternal hospital admission for childbirth
5.2. Duration of any admission (of baby) to special care
5.3. Health status at 6 months (EQ5D)
Sources of funding NIHR Health Technology Assessment Programme - HTA (UK)
Trial website
Publications 2007 protocol in: http://www.ncbi.nlm.nih.gov/pubmed/17201904
2012 results in: http://www.ncbi.nlm.nih.gov/pubmed/22375972
2014 follow-up results in: http://www.ncbi.nlm.nih.gov/pubmed/25127405
2014 results in: http://www.ncbi.nlm.nih.gov/pubmed/25158081
Contact name Ms  Sue  Cooper
  Address SNAP Trial Office
University of Nottingham
Academic Division of Obstetrics & Gynaecology
City Hospital Maternity Unit
Hucknall Road
  City/town Nottingham
  Zip/Postcode NG5 1PB
  Country United Kingdom
  Tel +44 (0115 823 1898
  Fax +44 (0)115 823 1908
  Email sue.cooper@nottingham.ac.uk
Sponsor University of Nottingham (UK)
  Address University Park
  City/town Nottingham
  Zip/Postcode NG7 2RD
  Country United Kingdom
  Sponsor website: http://nottingham.ac.uk/
Date applied 03/05/2005
Last edited 27/08/2014
Date ISRCTN assigned 21/06/2005
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