Raising awareness about chronic pain and dyspareunia among women – a Swedish survey 8 months after childbirth

1 Introduction

Chronic pain is a global health problem among women but there is still little awareness and recognition regarding this issue. Studies have shown that the prevalence of chronic pain is higher among women than men, and that women generally experience more recurrent, more severe and longer lasting pain [1], [2]. Conditions that disproportionately affect women include fibromyalgia, irritable bowel syndrome, pelvic pain and migraine headache [3], [4]. Several chronic pain conditions are unique to women’s reproductive organs, including endometriosis and vulvodynia.

Although considered as natural processes, pregnancy and labour often entail pain and tissue damage. Pain occurs in over 70% of pregnancies and the most common pain conditions affecting pregnant women are low back and pelvic girdle pain [5]. Acute pain during labour is experienced by the majority of parturients and is often rated as severe or extremely severe [6]. Furthermore, women suffer from painful injuries during vaginal birth, such as perineal lacerations of different degrees or levator ani muscle lesions as well as tissue damage during caesarean sections [7], [8], [9].

It is well established that an episode of acute pain, for instance, caused by trauma or surgery, may lead to development of chronic pain [10], [11]. Whereas the mechanisms of the transition from acute to chronic pain are still poorly understood, it is known that acute pain can induce maladaptive structural and functional changes in the nervous system. These changes may lead to physical and psychological consequences and, if left untreated, they may become irreversible with time and ultimately refractory to treatment [11], [12]. Chronic pain is a leading source of human suffering and disability [13] and can have negative consequences for individuals, their families, and society. In many cases, chronic pain leads to decreased quality of life and is associated with higher ratings of depression, anxiety, sleep disorders, complicated family relationships, an increased need for health care as well as decreased ability to work [1], [14].

Knowledge about chronic pain and dyspareunia after childbirth is still limited. Estimates of the prevalence of chronic pain following pregnancy or labour vary widely in the literature, from 8.5% to 43% concerning pain related to pregnancy [15], [16], [17], [18], [19] and 0.3%–55% regarding pain persisting after labour [10], [15], [20], [21], [22], [23], [24]. Moreover, the prevalence of dyspareunia after childbirth varied between 8% and 62% in previous studies [25], [26], [27], [28]. Several reasons for this large variation have been discussed, including heterogeneity with respect to study samples, follow-up period as well as that, in many previous studies, the authors did not discriminate between pre-existing pain and new onset of pain. To our knowledge, there are no studies focussing both on chronic pain following pregnancy and labour as well as dyspareunia. The aim of this study was to explore the prevalence of chronic pain 8 months after childbirth in a cohort of Swedish women. The characteristics of chronic pain, such as pain intensity, localization and frequency as well as pain interference with daily activities were examined. An additional aim was to describe the prevalence and intensity of dyspareunia.

2 Material and methods

3 Results

3.3 Characteristics of chronic pain after childbirth

A detailed analysis of characteristics of chronic pain 8 months after childbirth is shown in Table 2 and Figures 1–3.

Table 2:

Localization of chronic pain reported by women 8 months after childbirth with onset during pregnancy or following labour (more than one localization could be reported).

Localization	Pain onset
	During pregnancy n=142 (106a+36b)	Following labourc n=89 (53d+36b)	Following vaginal delivery n=61	Following caesarean section n=28
	n (%)	n (%)	n (%)	n (%)
In/around vulva	4 (3)	32 (36)	27 (44)	5 (18)
Surgical site after caesarean section	0 (0)	21 (75)e	0 (0)	21 (75)
In/around anus	6 (4)	15 (17)	14 (23)	1 (4)
Os coccyx	28 (20)	14 (16)	12 (20)	2 (7)
Lower back	65 (46)	13 (15)	10 (16)	3 (11)
Pelvis	62 (44)	10 (11)	9 (15)	1 (4)
Abdomen	12 (9)	10 (11)	6 (10)	4 (14)
Between vulva and anus	2 (1)	10 (11)	10 (16)	0 (0)
Legs or feet	21 (15)	3 (3)	3 (5)	0 (0)
Breasts	0 (0)	2 (2)	1 (2)	1 (4)
Upper back	26 (18)	1 (1)	0 (0)	1 (4)
Head	17 (12)	0 (0)	0 (0)	0 (0)
Arms or hands	6 (4)	0 (0)	0 (0)	0 (0)
1 site of pain	80 (56)	62 (70)	41 (67)	21 (75)
2–5 sites of pain	59 (42)	27 (30)	20 (33)	7 (25)
6–8 sites of pain	3 (2)	0 (0)	0 (0)	0 (0)

1. ^aChronic pain with onset during pregnancy.

2. ^bBoth chronic pain with onset during pregnancy and chronic pain with onset following labour.

3. ^cRegardless of delivery method.

4. ^dChronic pain with onset following labour.

5. ^eOf those women that had pain following caesarean section.

Figure 1:

Frequency of chronic pain 8 months after childbirth following pregnancy (n=137) or labour (n=84).

Figure 2:

Intensity of the worst and average chronic pain 8 months after childbirth following pregnancy (n=137–138) or labour (n=81–83) as well as dyspareunia (n=207) scored on NRS (0–10).

Figure 3:

Interference of chronic pain, following pregnancy and labour (n=190–192), with daily activities rated on a 0–10 numerical rating scale (NRS ranging from 0 – “no impact” to 10 – “very high impact”).

3.3.1 Localizations

The lower back and the pelvic area were the most common localizations for chronic pain following pregnancy. Regarding chronic pain with onset in relation to vaginal delivery, women experienced pain most often in/around the vulva and anus followed by pain around the os coccyx. The surgical site was the most prevalent localization of chronic pain after caesarean section (Table 2).

3.3.2 Frequency

Over 40% of the women experienced chronic pain constantly or daily (Figure 1).

3.3.3 Intensity

Approximately 80% of women with chronic pain with onset during pregnancy or in relation to labour scored their worst pain as moderate or severe (NRS 4–10). The corresponding number regarding average pain was between 50 and 70% (Figure 2).

3.3.4 Pain interference with daily activities

The women also evaluated the extent to which their pain interfered with their daily life activities including walking, work, childcare, sleep, mood, enjoyment of life and relations with others. More than 35% of the women rated pain interference with all these items as moderate or severe (4–10 NRS). Almost 60% of the women reported a moderate to severe (7–10 NRS) impact on mood (Figure 3).

3.4 Prevalence and intensity of dyspareunia

Nineteen-point two percent (211/1,098) of women experienced dyspareunia with onset during pregnancy or after labour. There was no difference regarding dyspareunia and the mode of delivery. Of those women that had a vaginal delivery, 19.5% (167/858) experienced pain during intercourse and the corresponding number for women after caesarean section was 18.3% (44/240) (p=0.694, OR 0.929, CI 0.6–1.3). Approximately 60% of women with dyspareunia scored their worst pain during intercourse as moderate or severe (NRS 4–10) (Figure 2).

4 Discussion

The results of our study indicate, that the prevalence of chronic pain after childbirth is lower than of chronic-postsurgical pain, for instance after mastectomy or amputation which may affect up to half of all patients [10], [12]. However, the caesarean and vaginal deliveries are the most common procedures worldwide and even a small percentage represent an impressive number of women. Extrapolation of our findings to the 120,000 deliveries per year in Sweden suggests that approximately 20,000 women are at risk of developing chronic painful conditions following pregnancy and labour [9].

Childbirth is also a risk factor for developing dyspareunia during the postpartum period and potentially in the longer term [25], [26], [27], [28]. In our study, 8 months after childbirth, almost one in five women reported pain during intercourse with onset during or after pregnancy. Previous studies suggest that postpartum dyspareunia may be a result of hormonal changes, such as relative hypoestrogenic state created by breastfeeding. Women, still breastfeeding at 6 months postpartum, had a higher likelihood of experiencing dyspareunia [27], [28]. Pain during intercourse may be also caused by mechanical trauma to the genital region, with ensuing inflammation or pelvic floor muscle dysfunction [26], [27], [28]. However, the findings regarding an association between the prevalence of dyspareunia and perineal trauma, as well as mode of delivery, are equivocal, except for instrumental vaginal deliveries that seem to increase the risk [27]. Our study confirms results showing no association between the prevalence of dyspareunia and the mode of delivery.

Previous studies of chronic pain or dyspareunia after childbirth show a great variability in terms of its prevalence, thus the findings are difficult to interpret and compare. Several reasons for the varied prevalence have been discussed, including heterogeneity with respect to study samples, outcome measures, and follow-up time. An important reason for the varied prevalence may be that many of the previous studies did not specify the onset of pain or did not exclude pre-existing pain [15]. It is also possible that the contributing factor to the different prevalence numbers is the varying time of natural recovery during the first year after the onset of pain. Studies have shown that some injuries demonstrated total or near total resolution up to 1 year after childbirth and that the prevalence of postpartum pain decreased with time [8], [15], [20], [34]. At the same time, some studies have found a relatively high prevalence of chronic pain up to 7 years after childbirth [19], [24], [35], [36]. Some authors suggest, that in most cases, spontaneous recovery from pregnancy-related lumbopelvic pain takes place within the first 3 months postpartum and women with pain persisting after this timeframe may have a poor prognosis [17], [34]. These results indicate that at least some pain conditions will not resolve with time in predisposed individuals [37].

In our study, the intensity of both chronic pain and dyspareunia were reported as moderate to severe in a significant proportion of women. In addition, chronic pain interfered considerably with women’s daily activities. The results suggest that pain can negatively affect women’s lives, which is consistent with studies demonstrating that the presence of persistent postpartum pain is associated with a reduced quality of life, higher prevalence of anxiety symptoms and depression compared to women without pain [17], [27], [38]. Moreover, pain can also affect mothers’ ability to care for their children [39]. Individuals with chronic pain are often at risk of developing further complications, including physical and psychological dysfunctions [14]. Chronic pain related to childbirth occurs relatively early in life, which means that the physical, psychological, social and financial consequences, for both individuals as well as society, may be extensive. Because chronic pain has the capacity to be more complex in its pathophysiology and thus potentially more difficult to treat with time [14], we suggest a more active approach to the identification and treatment of pain following childbirth in order to prevent potential long-term health problems, women’s suffering and increased need for health care. There is a need to raise awareness among healthcare providers of this clinical problem, as well as to revise and upgrade education regarding pain prevention and management.

The strengths of our study include the prospective study design, large sample size and the high response rate to the second questionnaire. Another key strength is that we clearly defined onset of chronic pain and excluded pre-existing pain. Further, the questionnaires were developed by an interprofessional and interdisciplinary team with broad competence. All items in both questionnaires seemed to be well perceived and easily understood by all women included in the study. To capture the multidimensionality of the pain experience, we measured recommended core outcomes, including pain intensity and interference with daily activities [32]. We also used valid and reliable instruments, such as NRS, to assess intensity of pain, which is recommended for core outcome measures in chronic pain studies [32]. The use of a Numeric Rating Scale for assessment of pain interference with daily activities was tested and explored in detail in the pilot study and well perceived by all study participants. Hence, the scale was deemed appropriate, valid, and reliable. Taken together, according to our evaluation, the questionnaires demonstrated good face-validity for their intended use, to capture concepts of interest in the target study population including pain intensity and interference with daily activities. The most important limitation of the study is that we were unable to determine a precise response fraction to the first questionnaire. The number of women included in the study constituted a minor proportion of the total number of deliveries at the recruiting hospitals during the data collection period (approximately 17,000) which to some extent could be attributed to the high levels of non-Swedish speaking women in the population. The share of foreign-born mothers in Sweden is reported as 27.5% [9]. Another reason for this limitation is that midwives on the maternity wards often failed to ask women if they would like to participate, due to time constraints, insufficient staffing and excessive workloads. However, the study participants seemed to be representative in relation to obstetric characteristics including mode of delivery, acute vs. elective caesarean sections and instrumental/non-instrumental vaginal deliveries. The recruitment did result in under-representation of younger women, women with lower educational level and foreign-born women with a non-Swedish-speaking background. Studies have shown, that lower educational level and socioeconomic status can be associated with higher prevalence of chronic pain [10], [40]. Therefore, it is possible that the prevalence of chronic pain after childbirth may be generally higher in the general population than among the women included in our study. Thus, the low number of women who filled in the first questionnaire may be a substantial threat to the generalizability of this study.

5 Conclusion

Our study shows that chronic pain 8 months after childbirth was reported by one in six women and one in five of the women experienced dyspareunia. The intensity of both chronic pain as well as dyspareunia was reported as moderate to severe in a significant proportion of women and the chronic pain considerably interfered with women’s daily activities.