Continuity in self-report measures of maternal anxiety, stress, and depressive symptoms from pregnancy through two years postpartum.

This study examined stability and change in maternal anxiety, stress and depression both during the second half of pregnancy and from pregnancy to six weeks and two years postpartum. Self-report measures included those designed to measure mood and state as well as more persistent attributes. Longitudinal data were collected from 137 women during pregnancy, 120 at six weeks, and 97 at two years. There was significant individual stability in scores on specific measures during pregnancy (range in Pearson rs=0.30-0.86) and from pregnancy through two years postpartum (rs=0.30-0.74). Comparable levels of convergence among measures of different constructs both within pregnancy and over time were also demonstrated, suggesting lack of precision in measurement instruments designed for specific constructs. Despite intra-individual stability, changes in mean levels were also observed over time with somewhat different patters for each variable. However, maternal parity was an important contributor to both level and trajectory. A summary composite score showed an elevated level of psychological distress during pregnancy in multiparous women, followed by a decline through two years postpartum; primiparous women displayed a gradual increase in distress [main effect F (1,87)=3.97, p < 0.05; time interaction F (2,174)= 7.15, p < 0.001] to multiparous levels by two years. Results are discussed in terms of a "motherhood" effect on psychological distress.