The answer is C. Half of peripartum mood episodes begin prior to delivery so vigilant monitoring of pregnant women is critical. In DSM-V, the postpartum specifier from DSM-IV was changed to peripartum-onset specifier; A is incorrect because this specifier requires that an episode begin during pregnancy or within 4 weeks of delivery (to best capture the effect of hormonal fluctuations). B and D are incorrect because postpartum psychosis has a 30-50% recurrence rate with each subsequent delivery and is more common in women with a personal or family history of bipolar disorder.

Publication reference : Payne JL. Recent advances and controversies in peripartum depression. Curr Obstet Gynecol Rep 2016; 5: 250-256.
Reference URL: https://www.ncbi.nlm.nih.gov/pubmed/27990322