Antenatal depression and anxiety across pregnancy in urban South Africa

Background: Depression and anxiety in pregnancy have negative consequences for women and their offspring. High adversity places pregnant women at increased mental health risk, yet there is a dearth of longitudinal research in these settings. Little is known about the pathways by which these problems emerge or persist in pregnancy. Methods: Women were enrolled in a prospective pregnancy cohort in Soweto, South Africa (2014-2016) and assessed using validated measures (Edinburgh Postnatal Depression Scale EPDS >= 13; State Trait Anxiety Index STAI >= 12) in early (T1) and later pregnancy (T2). Data was available for n = 649 women. Multinominal regression modelling was used to determine factors associated with transient versus persistent depression and anxiety across pregnancy. Cross-lagged panel modelling explored direction of effect between depression and anxiety, and stressors. Results: We found high rates of depression (T1: 27%; T2: 25%) and anxiety (T1: 15%; T2: 17%). Perceiving a partner made one's life harder increased risk of persistent depression (RR 5.92 95% CI [3.0-11.8] p<0.001); family stress increased risk for persistent anxiety (RR 1.71 95% CI [1.1-2.7] p = 0.027). We find evidence of a direct effect of early depression (T1) on later family stress (T2); and early family stress (T1) on later anxiety (T2). Limitations: We used screening measures of depression and anxiety rather than clinical interviews. Conclusions: Studies which focus only on late pregnancy may underestimate risk. Early identification, in the first trimester, is critical for prevention and treatment. Partner and family stressors are a key intervention target.