This randomized controlled trial will test an intervention called the Mastery Lifestyle Intervention (the MLI) that was developed from data of 1000+pregnant Hispanic women related to risks of preterm birth. The investigators will deliver a psychoeducational intervention that is manualized over 6 group sessions. The investigators will also have a usual care group that receives standard prenatal care. The investigators plan to enroll 238 pregnant women and start the study with them at 14-20 weeks gestation. The investigators will also test the biological response of the intervention by measuring Corticotropin Releasing Hormone, progesterone, estriol, and test for cotinine. The investigators will also determine any effect on infant outcomes at delivery.

To address the gaps related to interventions for Hispanic Mexican American and African American pregnant women, the investigators have developed and successfully pilot tested the Mastery Lifestyle Intervention (MLI): a culturally-relevant, manualized psychosocial group intervention that integrates two evidence-based behavioral therapies - Acceptance and Commitment Therapy (ACT) and Problem-Solving Therapy (PST). The MLI is a 6-week program designed to be integrated into regular prenatal care to facilitate more comprehensive care delivered by a nurse practitioner (NP) or certified nurse midwife (CNM). We propose the following hypotheses for a randomized controlled trial: Hypothesis 1a: Participants in the 6-week MLI will have decreased depressive symptoms, anxiety, stress, disengaged coping, and increased active coping compared to UC at end-of-treatment and after 6 weeks. Hypothesis 1b: The effects of MLI versus UC on depression, anxiety, stress, acculturative stress, and coping will be mediated via psychological flexibility and moderated by acculturation. Hypothesis 2a: Compared to UC, MLI participants will have significantly lower mean levels of CRH over time from baseline to end-of-treatment. Hypothesis 2b: Compared to UC, MLI participants will have significantly higher progesterone levels and lower estriol levels (higher progesterone/estriol ratios) over time from baseline to end-of-treatment. Hypothesis 3: As compared to UC, infants from mothers in the MLI group will have longer gestational age, greater birth weight, and fewer NICU admissions.

Inclusion Criteria:

• Providing informed consent;
• Ability to read and speak English
• Pregnant at 14-20 weeks gestation with one fetus, intrauterine pregnancy, gestational dating will be reviewed before enrollment via ultrasound administered per standard of care
• Self-identification as African American or Hispanics
• Age 18 to 45 years
• Currently living in the U.S.; Women who identify as just getting along, nearly poor, or poor upon prescreen.
• Women who score 10 or greater on the Center for Epidemiological Studies Depression Scale (CES-D) OR 5 or greater on the Generalized Anxiety Disorder-7 scale (GAD-7), or 14 or > on the Perceived Stress Scale as administered by clinical staff of the participating provider
• Willingness to adhere to the MLI regimen or usual care regimen

Exclusion Criteria:

After initial review of the electronic health record (EHR):

• Major systemic infections such as HIV, hepatitis
• <18 years of age or >45 years of age
• Enrollment in a prenatal program such as the Nurse Family Partnership
• Severe cognitive or psychiatric impairment per judgment of providers, that precludes cooperation with study protocol
• Inability to read English

Women who develop GDM after enrollment in the study will remain in the study. Development of hypertension or preeclampsia, pyelonephritis, or GDM will be considered an effect modifier in analysis of infant outcomes. Current antidepressant use will not be exclusionary and will also be used as an effect modifier. Further rationale for the exclusion criteria is:

• Only singleton pregnancies are included as the mechanisms of PTB are thought to differ with multiples.
• We do not exclude participants based on language (English or Spanish) spoken. We expect heterogeneity in language spoken and expect that there may be women who use both languages. Our prior study findings indicate that the risk of PTB is greatest among English-speaking and bilingual women, although we believe that all women will receive benefit from the MLI.
• Girls <18 are excluded as the intervention is designed to improve emotional wellbeing and quality of life in mature adults; girls <18 may not be cognitively ready for the adult intervention and may need an intervention tailored to their stage of development. Girls under 18 also have a different set of risks than women over 18 years of age.
• We will control the use of progesterone treatment statistically.
• Women who develop gestational diabetes after enrolling in the study will remain in the study.
• At enrollment or during the study, anyone who is prescribed antidepressant or anti-anxiety medications will be eligible for the study. We will make note of it and control it in analysis. If a participant is referred for individual therapy, we will obtain data from the prenatal record and control for that in the analysis

Pregnant Female between 14 to 20 weeks at the time of enrollment.

The PI will not be allowed to review any data that is not deidentified. The statistician will also not know which participant is in which group by participant names, only by deidentified data.

The clinical outcomes assessor will not know the group the participant has been in or their study number, but will know the participant names to be able to put the clinical outcomes in the database.