Methods: Women and their identified partners will complete a diagnostic interview, complete measures of depressive symptom severity at baseline, and be randomized to treatment with PA-IPT or TAU. Women randomized to TAU will be treated by UNC physicians according to the UNC-CH Perinatal Psychiatry Program's algorithm for treatment of prenatal MDD (usually one of a number of antidepressant medications, tailored to the individual, although some women may opt against medication altogether and still be eligible to enroll). Women randomized to PA-IPT will participate in 8 therapy sessions with their identified partner over a 12-week period, along with one refresher session at or around 6 weeks postpartum. Women and partners will be assessed for change in depressive symptoms and relationship satisfaction during pregnancy at visits 4 and 8, and postpartum at 6-week and 6-month visits.