The association between maternal cortisol and depression during pregnancy, a systematic review.

Timing of cortisol collection during pregnancy is an important factor within studies reporting on the association between maternal cortisol and depression during pregnancy. Our objective was to further examine the extent to which reported associations differed across studies according to time of maternal cortisol collection during pregnancy. On December 15, 2016, records were identified using PubMed/MEDLINE (National Library of Medicine), EMBASE (Elsevier; 1974-), Cumulative Index to Nursing and Allied Health Literature (CINAHL, EBSCO), PsycINFO (EBSCO), and Web of Science Core Collection (Thomson Reuters). Unique abstracts were screened using the following inclusion criteria: (1) maternal cortisol assessed during pregnancy; (2) antepartum depression assessed during pregnancy using a screening instrument; (3) reports on the association between maternal cortisol and antepartum depression; (4) provides information on timing of cortisol assessment during pregnancy, including time of day and gestation; and (5) not a review article or a case study. One thousand three hundred seventy-five records were identified, resulting in 826 unique abstracts. Twenty-nine articles met all inclusion criteria. On balance, most studies reported no association between maternal cortisol and antepartum depression (N = 17), and saliva and blood were the most common reported matrices. Morning and second and third trimesters were the most common times of collection during pregnancy. Among studies reporting an association (N = 12), second-trimester and third-trimester cortisol assessments more consistently reported an association and elevated cortisol concentrations were observed in expected recovery periods. Our review adds to the existing literature on the topic, highlighting gaps and strategic next steps.