Aim: The aim of this study was to highlight a link between childbirth pain and mood disorders in the immediate postpartum.
Method: We met 43 women at three days postpartum in a maternity unit in Toulouse (France) between January and April 2004. The mean age of the mothers was 30 years (S.D., 4.8 years; range, 18-39 years). Mothers were excluded if they did not speak French, if they had past psychiatric history, and if their baby was premature, ill, or stillborn. Pain was measured using a French version of the McGill pain questionnaire (Melzack, 1975) [Br J Psychiatry 171 (1997) 550-555]. This questionnaire called questionnaire douleur Saint-Antoine (QDSA) is composed of 58 words and 16 classes (Boureau et at., 1984) [Thérapie 39 (1984) 119-129]. Classes 1-9 provide data on the sensory qualities of pain while Classes 10-16 reflect affective characteristics. Blues symptoms was assessed with the French version of the maternity blues questionnaire of Kennerley and Gath (1989) [Br J Psychiatry 145 (1984) 620-625]. For each 28 items women have to decide how much change there is from their usual self, by ticking one choice out of five, from "much less than usual" to "much more than usual". We used the French version of the EPDS (Cox et al., 1987) [Br J Psychiatry 150 (1987) 782-786]. This scale was used to assess the intensity of depressive mood.
Results: The results revealed a significant positive correlation between the pain scores and the "maternity blues" questionnaire scores, and between pain scores and EPDS score at three days postpartum. This study shows a stronger association between intensity of postpartum blues and affective aspect of childbirth pain (r=0.48; p<0.05) than between blues and sensorial aspect of pain (r=0.40; p<0.05). The level of depressive mood was found to be associated with affective (r=0.32; p<0.05) but not with sensory qualities of childbirth pain (r=0.28; p<0.05). In a multiple regression analysis predicting intensity of postpartum blues, we entered sensorial and affective scores of QDSA, age, and postpartum blues scores. The subjects to predictors ratio was adequate for multiple regression analysis as it was around the traditional guideline of at least ten participants per predictor [Howell DC. Statistical methods for psychology. Fourth ed. Duxbury press; 1997]. This model accounted for 31% of the variance of intensity of blues (F3,39=5.9, p=0.002). Affective dimension of pain was the only significant predictor (p=0.36, p=0.047). In another multiple regression analysis predicting intensity of depressive mood, we entered the same predictors. This model accounted for 20% of the variance of blues intensity (F3,39=3.26, p=0.03). Age was the only significant predictor (beta=-0.31, p=0.04). These results confirm our hypothesis that intensity of the childbirth pain is associated with mood disorders in the immediate postpartum. Several explications can be advanced. First, maternity blues could be a reaction to stress caused by childbirth pain. Moreover, pain can be felt as a failure for women who prepared themselves to a painless labor. Indeed, the prepared childbirth training pretends to give women the ability to overcome pain through physical and mental training. Thus, their responsibility in coping with the labor is heavy and might make them feel guilty if they fail. In addition, since "the labor itself should be experienced as a positive moment" [Chertock L. Féminité et maternité: étude clinique et expérimentale sur l'accouchement sans douleur. Paris: Desclée de Brouwer; 1996], pain might be at the origin of a great disappointment [Acta Obstet Gynecol Scand 83 (2004) 57-61]. It should be noted that we used the QDSA as a measure of past pain and not as a measure of immediate pain, as Melzack recommended [Pain 1 (1975) 277-299].
Conclusion: According to the results of this study, our hypothesis assuming a link between the intensity of labor pain and mood disorders in early postpartum appears to be confirmed. The intensity of postpartum blues is the best predictor of postnatal depression. Hence, knowledge of the risk factors, such as pain, could help to improve the efficiency of detection, and let professionals focus on the psychological impact of labor and especially on post-traumatic stress disorders.