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

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.