Each class will be outlined as follows: 1) opening greeting/intention setting, 2) pranayama (i.e., breathing exercises), 3) warm-up/sun salutations (i.e., flowing sequence), 4) yoga sequence (e.g., combination of sun salutations, vinyasa, and standing, seated, and/or balancing poses), 5) cool-down 6) Savasana (i.e., final resting pose), and 7) class closing. Meditation and breath awareness (e.g., linking each movement with breath) will be emphasized throughout each class. All classes will focus on safety and alignment and be appropriate for women during pregnancy by incorporating modifications to poses/exercises as necessary (e.g., yoga block, strap). Certified yoga instructors with a bachelors degree in a health related field and experience teaching pregnant women will instruct all yoga classes. Participants will be provided with a 'yoga during pregnancy' safety packet that includes a list of prenatal yoga poses that women may do at their own leisure at home.

Participants will be asked to attend a group-based pregnancy education group (similar to a birth education class). The class format will include a didactic portion followed by group discussion (N=12). The following evidence-based topics (based on the American College of Obstetrics and Gynecologists) to be discussed may include (but not limited to): financial management in preparation for baby, preparing for labor and delivery, transitioning into motherhood, sleep hygiene, and baby bonding. A labor and delivery nurse and certified Dula will instruct all classes.

The prenatal yoga classes will be offered at Urban Wellness (2024 N. 7th St., Phoenix, AZ 85006). Classes will be offered Tuesdays's from 4:15-5:30 pm and Saturday's from 9:00-10:15 am. Participants will be able to attend both classes if they so choose but are only asked to attend 1/week. Participants will be asked to arrive to class at least 10 minutes early in order for the research team to collect their weight in a private room. Additionally, if participants have attended at least 70% of classes (1 per week for 8/12 weeks), participants will be able to attend sessions up until birth (beyond the 12-week intervention) if they so choose. If participants decide to attend classes beyond the 12-week intervention the investigators will continue to collect their weight at each session.

Acceptability (defined as satisfaction, intent to continue use, perceived appropriateness); Benchmarks for acceptability include ≥70% of the sample will report the yoga intervention to be a satisfactory, useful, and appropriate modality to prevent excessive GWG.

Demand was measured using attendance/adherence to the yoga intervention. Attendance was tracked by a researcher who was present at each yoga session. Benchmarks for demand include ≥60% of participants in each group will attend one class per week.

Weight gain exceeding IOM recommendations