A total of 298 eligible pregnant women were approached at T1, 20 women refused to participate and 278 completed the first survey (T1: 6-12 gestational weeks), with a response rate of (93.3%). There were 83 women who miscarried after the first measurement and were excluded at T2, 16 pregnant women dropped out at T2. Three women who miscarried after the second measurement and were excluded at T3. Ten women dropped out at T3. Thus, at T2 and T3, 179 and 166 pregnant women completed the second and the third measurement respectively. The recruitment process and the flow of the study are presented in Figure 1. There was no significant difference in demographic characteristics between the women who completed the three measurement and those who did not.
Sample characteristics
Table 1 presents the demographic and antenatal characteristics of the participants. The mean age of the participants was 31.87 years (SD = 4.21). More than 54.2% of the participants had three or more miscarriage previously. 59.6% of the participants had been married for more than five years. Over 74.1% of the participants were childless.
Changes over time in depression
Table 2 presents the ANOVA results of the study variables. An ANOVA revealed the main effect of time, indicating significant mean differences in depression from the first trimester to the third trimester (F [2, 330] = 8.184, p < 0.001). Repeated contrasts for time indicated that antenatal depression scores declined from the first trimester to the second trimester (F [1,165] = 5.887, p = 0.016). The change in antenatal depression scores between the second trimester and the third trimester was not significant (F [1,165] = 2.035, p = 0.156). A paired t-test revealed that the level of depressive symptoms at the first trimester was much higher than those at the third trimester (t [165] = 4.371, p < 0.001). The scores of depression across the three trimesters of pregnancy are presented in Figure 2-a. Furthermore, the occurrence of depressive symptoms at T1, T2, and T3 was 38.0% (n = 63), 34.3% (n = 57) and 31.3% (n = 52) respectively.
Changes over time in anxiety
An ANOVA revealed the main effect of time, indicating significant mean differences in anxiety across the three trimester of pregnancy (F [2, 330] = 25.239, p < 0.001; Table 2). Repeated contrasts for time showed that the SAS scores declined from the first trimester to the second trimester (F [1,165] = 17.097, p < 0.001) and then the third trimester (F [1,165] = 8.143, p = 0.005). A paired t-test revealed that the level of anxiety symptom at the first trimester was much higher than those at the third trimester (t [165] = 7.465, p < 0.001). The scores of anxiety across the three trimesters of pregnancy are presented in Figure 2-b. Furthermore, the occurrence of anxiety symptoms at T1, T2 and T3 were 47.6% (n = 68), 36.1% (n = 60) and 32.5% (n = 55) respectively.
Changes over time in social support
An ANOVA revealed the main effect of time, indicating significant mean differences in social support over the course of the pregnancy (F [2, 330] = 4.037, p = 0.018; Table 2). Repeated contrasts for time indicated that social support scores increased from the first trimester to the second trimester (F [1,165] = 7.351, p = 0.007). The change in social support between the second trimester and the third trimester was not significant (F [1,165] = 0.657, p = 0.419). A paired t-test revealed that the level of social support at the first trimester was much lower than those at the third trimester (t [165] = 2.023, p = 0.045). The scores of social support across the three trimesters of pregnancy are presented in Figure 2-c.
Relationships among the study variables
Table 3 presents the relationships among study variables. The correlations between anxiety and depression, anxiety and social support, depression and social support at each time point were significant (p<0.001) .