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Smoking Reduction In Gravid Substance Use Disorders

Smoking Reduction In Gravid Women With Substance Use Disorders (SIGS): A Randomized Controlled Trial

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT04132232
Acronym
SIGS
Enrollment
74
Registered
2019-10-18
Start date
2021-02-15
Completion date
2023-12-01
Last updated
2024-08-05

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Tobacco Smoking, Tobacco Smoking in Mother Complicating Pregnancy, Tobacco Use Disorder

Keywords

smoking in pregnancy, substance use disorder, carbon monoxide, fetal carboxyhemoglobin

Brief summary

The aim of this study is to encourage smoking cessation in women with substance use disorders by providing knowledge of expired carbon monoxide. We hypothesize that women who are provided knowledge of their expired carbon monoxide and the associated percent fetal carboxyhemoglobin will have a greater success at quitting smoking during pregnancy than women who are not provided this information. A secondary aim of the study is to correlate expired carbon monoxide throughout pregnancy with infant birth weight.

Detailed description

This is a randomized controlled trial. Pregnant smokers who are substances users who meet inclusion criteria will be offered participation in the study at their first obstetrical appointment. Patients who consent to participate will be randomized. At the enrollment/randomization visit, women will be randomized to either the intervention (knowledge of and interpretation carbon monoxide levels and associated percent fetal carboxyhemoglobin) or control group (no information on carbon monoxide and associated percent fetal carboxyhemoglobin). Allocation will be computer generated. This will be done after the patient meets all inclusion criteria. If randomization to the intervention arm, the patient will be notified of carbon monoxide and associated fetal carboxyhemoglobin levels at each obstetrical visit and counseled on how it affects maternal and fetal health. If randomized to the control arm, the patient will have expired carbon monoxide and associated fetal carboxyhemoglobin levels measured at each obstetrical visit but blinded to these results. These patients will not be notified of the levels, nor counseled on what levels mean for maternal or fetal health. See below for intervention and control protocols. Maternal demographic (age, race, socioeconomic status), medical history (other medical problems, medications, height, weight) and obstetric history (parity, gestational age) data will be abstracted from the patient's chart and supplemented with a patient questionnaire at the enrollment/randomization visit. The primary outcome is the expired maternal carbon monoxide level at the last obstetric visit or at delivery. This will be determined by the Smokerlyzer device used to measure this. Secondary aims of the study will be to evaluate how maternal carbon monoxide levels correlate with fetal growth, cigarette use per day, patient satisfaction and neonatal birth weight. All patients will have the following performed at the enrollment/randomization visit and subsequent prenatal visits: a. The order of events for all patients will be as follows: i. Blood pressure evaluation ii. Weight iii. Fundal height iv. Patient will be asked the number of cigarettes used per day v. Patient will exhale into Smokerlyzer device to obtain expired carbon monoxide and associated percent fetal carboxyhemoglobin vi. Patients will be provided smoking cessation resources and counseling on smoking cessation in pregnancy Intervention Protocol 1. Intervention group will undergo Smokerlyzer ® exhaled carbon monoxide measurements at enrollment, each prenatal visit, and at their last (\>36 week) prenatal visit or at delivery if not captured in clinic. 2. Women will be informed of their exhaled carbon monoxide measurement at each visit as well as the correlation to fetal carboxyhemoglobin. 3. At each visit, the intervention group will receive counseling on fetal impact of smoking based on fetal carboxyhemoglobin level and institutional and state information on smoking cessation will be provided. 4. The patient will then proceed to the remainder of the obstetrical visit. Control Protocol 1. Women in the control group will undergo Smokerlyzer ® exhaled carbon monoxide measurements at enrollment, each prenatal visit and at their final (\>36 week) prenatal visit or at delivery if not captured in clinic. 2. Both levels (maternal carbon monoxide and fetal carboxyhemoglobin) will be recorded by the co-investigatory, but NOT disclosed to the patient 3. At each visit, control group will be provided institutional and state information on smoking cessation if they report continued smoking. 4. The patient will then proceed to remainder of the obstetrical visit. For both groups: At the time of delivery, maternal and neonatal outcome data will be recorded from the chart, including gestational age at delivery, mode of delivery, indications for delivery, birth weight, Apgar score, cord blood gas, length of stay, and neonatal complications, if any. A survey will be completed for both intervention and standard care groups after delivery.

Interventions

DIAGNOSTIC_TESTknowledge of expired maternal carbon monoxide and fetal carboxyhemoglobin levels

Will use the Smokerlyzer® device at each visit and be provided information on exhaled carbon monoxide and fetal carboxyhemoglobin. Risks of adverse perinatal outcomes related to maternal carbon monoxide and fetal carboxyhemoglobin level will be provided.

Sponsors

University of Alabama at Birmingham
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Subject)

Masking description

Will not discuss percent fetal carboxyhemoglobin to control group versus disclosing percent fetal carboxyhemoglobin to intervention group.

Intervention model description

Randomized controlled trial

Eligibility

Sex/Gender
FEMALE
Age
16 Years to 45 Years
Healthy volunteers
Yes

Inclusion criteria

i. Age 16-45 ii. Singleton gestation iii. Gestational age at enrollment \<24 weeks iv. Substance use disorder defined as modified National Institute on Drug Abuse ASSIST ≥4 v. Cigarette smoker using ≥10 cigarettes/day interested in quitting

Exclusion criteria

i. Known or suspected fetal growth restriction at enrollment ii. Known fetal anomaly, aneuploidy, or demise iii. Not interested in smoking cessation or reduction during pregnancy iv. E-cigarette use

Design outcomes

Primary

MeasureTime frameDescription
Prevalence of Smoking ≥ 10 Cigarettes/Day in Each Group at Final Measurement by Exhaled Carbon Monoxide LevelFinal measurement (last prenatal care visit or at delivery)Prevalence of smoking ≥ 10 cigarettes/day in each group at final measurement by exhaled carbon monoxide level at last prenatal visit prior to delivery, as measured by exhaled carbon monoxide

Countries

United States

Participant flow

Participants by arm

ArmCount
Treatment Group
1. The patient will exhaled into the Smokerlyzer® device will at each visit 2. Exhaled carbon monoxide and fetal carboxyhemoglobin levels will be disclosed to the patient 3. Risks of adverse perinatal outcomes related to maternal carboxyhemoglobin and fetal carboxyhemoglobin level will be provided. knowledge of expired maternal carbon monoxide and fetal carboxyhemoglobin levels: Will use the Smokerlyzer® device at each visit and be provided information on exhaled carbon monoxide and fetal carboxyhemoglobin. Risks of adverse perinatal outcomes related to maternal carbon monoxide and fetal carboxyhemoglobin level will be provided.
37
Control Group
1. The patient will exhale into the Smokerlyzer® device at each visit. 2. Exhaled carbon monoxide and fetal carboxyhemoglobin level will NOT be disclosed to the patient 3. No risks of adverse perinatal outcomes related to maternal carbon monoxide and fetal carboxyhemoglobin levels will be provided
37
Total74

Withdrawals & dropouts

PeriodReasonFG000FG001
Overall StudyLost to Follow-up67
Overall StudyRandomized but met exclusion criteria.11

Baseline characteristics

CharacteristicTreatment GroupControl GroupTotal
Age, Categorical
<=18 years
2 Participants0 Participants2 Participants
Age, Categorical
>=65 years
0 Participants1 Participants1 Participants
Age, Categorical
Between 18 and 65 years
35 Participants36 Participants71 Participants
Age, Continuous30.3 years
STANDARD_DEVIATION 6.9
32.4 years
STANDARD_DEVIATION 9.4
31.3 years
STANDARD_DEVIATION 8.2
Average number of cigarettes per day at enrollment12.3 cigarettes
STANDARD_DEVIATION 3.8
12.6 cigarettes
STANDARD_DEVIATION 4.4
12.4 cigarettes
STANDARD_DEVIATION 4.09
Expired Maternal Carbon Monoxide Level at randomization15.4 ppm
STANDARD_DEVIATION 8.8
11.2 ppm
STANDARD_DEVIATION 5.5
13.4 ppm
STANDARD_DEVIATION 7.6
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Asian
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Black or African American
11 Participants12 Participants23 Participants
Race (NIH/OMB)
More than one race
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Unknown or Not Reported
0 Participants1 Participants1 Participants
Race (NIH/OMB)
White
26 Participants24 Participants50 Participants
Sex: Female, Male
Female
37 Participants37 Participants74 Participants
Sex: Female, Male
Male
0 Participants0 Participants0 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
0 / 370 / 37
other
Total, other adverse events
0 / 370 / 37
serious
Total, serious adverse events
0 / 370 / 37

Outcome results

Primary

Prevalence of Smoking ≥ 10 Cigarettes/Day in Each Group at Final Measurement by Exhaled Carbon Monoxide Level

Prevalence of smoking ≥ 10 cigarettes/day in each group at final measurement by exhaled carbon monoxide level at last prenatal visit prior to delivery, as measured by exhaled carbon monoxide

Time frame: Final measurement (last prenatal care visit or at delivery)

Population: Participants who had expired carbon monoxide measured at either their last prenatal visit or at delivery.

ArmMeasureValue (NUMBER)
Treatment GroupPrevalence of Smoking ≥ 10 Cigarettes/Day in Each Group at Final Measurement by Exhaled Carbon Monoxide Level22 participants
Control GroupPrevalence of Smoking ≥ 10 Cigarettes/Day in Each Group at Final Measurement by Exhaled Carbon Monoxide Level16 participants
p-value: 0.06Chi-squared

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026