50-70% of adolescents gain too much weight during pregnancy, and this excess gain significantly increases their risk of high postpartum weight retention and long-term obesity. In this randomized controlled pilot study, the investigators are evaluating the feasibility and acceptability of a relatively brief interpersonal psychotherapy program for reducing excess gestational weight gain during adolescent pregnancy. Compared to treatment-as-usual prenatal care delivered in an adolescent maternity clinic, the investigators will estimate the added benefit of an interpersonal psychotherapy program's effectiveness for reducing excess gestational weight gain, improving maternal postpartum insulin sensitivity, and decreasing maternal and infant adiposity.

Obesity and its negative health consequences such as type 2 diabetes and heart disease are major public health concerns. Pregnancy is an ideal opportunity to intervene with young women both to reduce their own likelihood of long-term obesity and to potentially lessen their offspring's obesity risk. Interventions to reduce excessive weight gain during adolescent pregnancy may be particularly important. 50-70% of adolescents gain too much weight during pregnancy, and this excess gain significantly increases their risk of high postpartum weight retention and long-term obesity. Depression and stress-which are common in adolescent pregnancy-also may play a role. Pregnant adolescent females, as well as non-pregnant females, who have more frequent feelings of depression or stress are more likely to gain weight too rapidly or to gain too much weight as they grow. In the current project, the investigators seek to develop a program to prevent excess weight gain that will be feasible to administer in the Colorado Adolescent Maternity Program (CAMP) at Children's Hospital Colorado, University of Colorado Denver, Anschutz Medical Campus, and, that will be acceptable to pregnant teens at-risk for gaining too much weight. After a screening assessment, adolescent females (13-19y) will be randomly assigned to participate in either a 6-session interpersonal psychotherapy (IPT) program + usual care or to CAMP usual care only. The IPT program will involve 6 1-hour meetings with a trained facilitator and focus on improving relationships, mood, stress, and eating in response to negative feelings. The investigators will assess participants midway through the program, immediately after the program, and again at a 3-month postpartum follow-up. The investigators will evaluate to what extent adolescent females attend the program, complete at-home practice assignments, and show changes in mood, stress, relationships, eating, and mindfulness before and after IPT participation compared to usual care only. The investigators also will estimate how program participation relates to weight gain during pregnancy and 3-month postpartum maternal weight retention, adiposity, and insulin sensitivity. The investigators also will study the adiposity of adolescents' 3-month-old infants.

Inclusion Criteria:

• 13-19 years of age and the 3-6 month old infants of these adolescent mothers
• Female
• Pregnant, 12-18 weeks gestation
• Patient in the Colorado Adolescent Maternity Program (CAMP) clinic

Exclusion Criteria:

• Full-syndrome Diagnostic and Statistical Manual of Mental Disorders (DSM)-5 psychiatric disorder that, in the opinion of the investigators, would impede study compliance and necessitate more intensive treatment (e.g., conduct disorder, schizophrenia, major depressive disorder with active suicidal ideation)
• Major renal, hepatic, endocrinologic (hyperthyroidism or Cushing syndrome), or pulmonary (other than mild asthma) disorder
• Medication affecting mood or body weight
• Major high-risk pregnancy complication (preeclampsia, gestational diabetes, hypertension, multiple gestation, placenta previa, membrane rupture, incompetent cervix)
• Pre-pregnancy BMI <5th percentile for age and sex

Care providers delivering usual prenatal care are unaware of condition assignment.