Modifying Progesterone and Estradiol Levels to Prevent Postpartum Cigarette Smoking Relapse and Reduce Secondhand Smoke Exposure in Infants and Children

Inclusion Criteria:

* Ability to provide informed consent,
* Aged 18 to 45 years old
* Self-reported stable physical and mental health

  1. self-report uncomplicated pregnancy at gestational week 30 or beyond, or
  2. self-report the birth of a child within the past 6 months
* History of ≥ 4 cigarettes per month during the six months prior to pregnancy
* At enrollment, self-report of motivation to become and/or remain abstinent after delivery ≥ 6 on a 10 point Likert-type scale
* Willingness to protect against pregnancy following day 0 to week 12 of the study
* Participants must live in the continental US and have a device to fully participate in the protocol

Exclusion Criteria:

* Current daily use of nicotine replacement therapy or smoking cessation medications, with the exception of e-cigarettes
* Current major depressive disorder based on the Patient Health Questionnaire-9 (PHQ-9) and the Beck Depression Inventory
* Contraindication to progesterone treatment (e.g., current use of drugs that may inhibit CYP3A4; current or history of deep vein thrombosis, pulmonary embolus, clotting or bleeding disorder, hypertension, stroke, heart disease, or liver dysfunction or disease; or peanut allergy),
* Current or within the past 3 months treatment for illicit drug use or alcohol use
* Any condition or issue that, in the opinion of the clinical team, precludes participation in the trial.