The aim of the present study was to evaluate the psychological changes of women with low-risk pregnancies. The results showed that the level of anxiety and depression increases from the beginning of pregnancy to the second trimester of pregnancy and has an inverse relation with the level of education. The relationship between education level and psychological health has already been reported; however, the increase in the level of depression and its relative frequency in the present study is in contrast with the results of other research carried out on the general population and indicated a slowdown in depression during pregnancy [20, 22].Hu et al also reported that the frequency of depression decreases during the three trimesters of pregnancy . Comparing the prevalence of depression in her study in the first trimester of pregnancy (14.0%), with the present study suggests that women with low-risk pregnancy start pregnancy with less depression, but with the advancement of pregnancy, the level of depression increases. This incremental trend observed in the level and relative frequency of depression in Iranian women is consistent with the high prevalence of depression reported in pregnant women in the general population of Iran . Previous studies have been reported that that the prevalence of depression in pregnant women was 22.8% in the third trimester . With increasing the gestational age, women's need for social support from the family and support for pregnancy delivery systems increases. A study in this field indicates a reverse relationship between the level of depression in women and the belief in the comprehensive support of the pregnancy care systems .In a qualitative study, women with a history of postpartum depression stated that lack of social support from the family and care providers caused them discomfort . However, the research findings indicate that the level of social support for Iranian pregnant women is low , many of them were not satisfied with the quality of pregnancy care . Although the increase in the level of depression until the second trimester of pregnancy can be explained by the results of these studies, the decrease in depression level in the third trimester of pregnancy was surprising in the present study. Because women's physical constraints due to the increasing age of pregnancy and the common discomfort of this period are factors that can endanger the psychological health of women .The findings of this study indicate that the level of depression in women studied was less influenced by the physical conditions of pregnancy. However, although the level of depression in women was dependent on their level of education, the level of depression in them was independent of this factor. So that the changes observed were not related to their educational level. The reverse correlation between education level and depression level has already been reported . In the present study, unlike the Chi study, there was no relationship between the conditions of planning for pregnancy. However, the probability of unwanted pregnancy in women with a lower educational level is higher . Therefore, the relationship between unwanted pregnancy and depression may be overshadowed by the level of education.
Another finding of the study showed an increase in the level of anxiety during the first and second trimmers. Also, the results showed that level of anxiety during the first trimester, such as depression level, had a reverse relationship with the level of education of women. In addition, there was a negative relationship between its level and planning for pregnancy. This finding suggests that non-planning for pregnancy, although not affecting the level of depression, is associated with increased anxiety in pregnant women. But increasing the gestational age independent of this factor is associated with an increasing change of anxiety levels. Also, the findings suggest that, unlike depression, the level of anxiety does not decrease in the second and third trimesters.
The observed association between the level of anxiety and planning for pregnancy confirms the results of Gariepy's study, which reported that unplanned pregnancy is associated with an increased risk of anxiety disorder . The relationship between anxiety and maternal education has also been reported in another study . The observed increase in the level of anxiety as well as its prevalence with the progression of pregnancy was also in line with the study of Hu et al., which showed that the anxiety prevalence increased in the second trimester compared to the first trimester. In Zhang's report, the prevalence of pregnancy anxiety increased between the first and second trimester. But in the Zhang study, the prevalence of anxiety was 22.7% in the first trimester of pregnancy . However, the prevalence of anxiety in this study was 2.8%. This finding suggests that women with uncomplicated pregnancy have better conditions for negative psychological symptoms, but an increase in anxiety is experienced in all women, and this incremental change is not influenced by social status, such as education level.
Other findings showed that the level of depression and anxiety in any of trimester of pregnancy depended on the level of these psychological symptoms in the previous trimester. Other studies have shown that pre-pregnancy depression and anxiety are associated with an increase in the probability of these disorders in pregnancy. The results of this study showed that in people with a history of depression and anxiety disorders in pre-pregnancy, the level of anxiety and depression in the early stages of pregnancy can predict the level of these symptoms in the next stages of pregnancy.
The results of this study indicate that the level of depression and anxiety in women with low complications increases with increasing gestational age, but it should be noted that existing economic fluctuations, which can affect the psychological health of people in society, may have affected the results of the current research and are considered as research constraints.