Pain in the thumbs and wrist in postpartum women, also known as ‘mummy thumb’(Walkinshaw, 2011) and ‘baby wrist’ (Anderson et al, 2004) is a common problem among postpartum mothers (Sit et al, 2017). Postpartum women frequently use their hands and wrists when carrying, breastfeeding, bathing and changing their babies' clothes (Johnson, 1991; Kiyoshige, 1993), and excessive use of the hands and wrists is associated with the onset of pain (Anderson et al, 2004; Afshar and Tabrizi, 2021). Studies on hand and wrist pain assessment in postpartum women have involved self-reports of noticed pain using a telephone survey (Sit et al, 2017), questionnaires administered at infant medical checkups (Satoh et al, 2017) and assessments of pain noted in daily life or experienced in a pain-inducing test by a physician (Skoff, 2001; Avci et al, 2002). There is no gold standard for the self-assessment of hand and wrist pain in postpartum mothers and its impact on their quality of life is unknown.
Some cross-sectional studies on hand and wrist pain in postpartum mothers, which describe the time of onset and course of hand and wrist pain after birth, have targeted patients diagnosed with de Quervain tenosynovitis who consulted medical institutions (Avci et al, 2002; Capasso et al, 2002). Although hand and wrist pain may resolve spontaneously, some affected people may develop conditions such as de Quervain tenosynovitis, which require medical and surgical treatment, but do not become severe when diagnosed and treated early (Capasso et al, 2002; Ring and Schnellen, 2009; Larsen et al, 2021).
Changes over time in hand and wrist pain in postpartum women with de Quervain tenosynovitis have been reported (Avci et al, 2002; Anderson et al, 2004); however, the course of hand and wrist pain among those with no diagnosis by a physician remains unclear. A previous study of postpartum women in Japan showed that although 181 of 514 participants (35%) subjectively noticed pain, none sought medical advice, suggesting that it may be uncommon for postpartum mothers with hand and wrist pain to consult a medical institution and receive a diagnosis in Japan (Satoh et al, 2017). Breastfeeding involves a variety of repetitive actions that can cause strain or injury to the wrist, thumb or hand. Although it has been reported that hand and wrist pain after birth can be resolved without medical treatment by stopping breastfeeding (Avci et al, 2002), pain can persist for 8–10 months after birth, even among women who are not breastfeeding (Anderson et al, 2004; Satoh et al, 2017). Not only may cessation of breastfeeding not address the injury, it can also affect the health of the baby and cause stress to the mother; exclusive breastfeeding is recommended by the World Health Organization (2022) for at least 6 months. While in some cases, hand and wrist pain may resolve naturally, it can persist for months or progress into a chronic condition, causing unnecessary pain and leading to disability, inevitably affecting daily living (Sit et al, 2017). It is important to consider postpartum mothers' specific needs and adequate approaches to the early detection and long-term postpartum management of hand and wrist pain.
The present study aimed to assess the course of hand and wrist pain among postpartum women for 9 months after birth, using selected, easy-to-use self-assessment tools. The focus was the relationship between self-assessed hand and wrist pain and upper extremity disability among postpartum mothers and determining the effect of hand and wrist pain on quality of life during childrearing.
Methods
Design
A prospective cohort study design was used. Participant recruitment was conducted between August and December 2016 and research was conducted between August 2016 and June 2017.
Participants and setting
The target population was women who had given birth at two institutions, a general hospital and a clinic, in the south of Japan. Cross-sectional research was conducted at 2, 6 and 9 months after birth.
A previous cross-sectional survey of hand and wrist pain in Japanese women 1–8 months after birth revealed an onset rate of 50% among first-time mothers and 25% among multiparous mothers (Satoh et al, 2017). Therefore, setting the level of significance at 0.05 and power at 0.8, a sample size of 58 first-time and 58 multiparous mothers was calculated, totaling 116 participants.
Data collection
Questionnaires used to collect data were distributed to postpartum mothers in the selected settings to be filled out within 5 days of birth, and deposited in a box at the institution. Consenting participants who returned the completed questionnaire were registered and surveyed by mail 2 and 6 months after birth.
Participants' addresses and full names were collected in the first stage of data collection because it was deemed necessary to refer participants who exhibited abnormal upper extremity disability scores to an orthopedic specialist 6 months after birth. ID numbers were assigned to these data for linkable analysis. The link table of personally identifiable information and ID numbers was safely stored in a locker, the key to which was kept by the principal researcher.
The questionnaires asked for participants' demographic and obstetric background (age, number of births, history of hand and wrist pain, experience of medical diagnosis/treatment) and current hand and wrist pain. The measurement tools used in the questionnaire included Eichhoff's test, which assessed hand and wrist pain, Hand20 (NPO Hand Frontier, 2007), which assessed upper extremity function, and the EQ-5D-5L (EuroQOL Research Foundation, 2022), which was used to assess general quality of life. All scales were used with permission of the developers.
Subjective hand and wrist pain self-report
For subjective hand and wrist pain, participants were asked ‘have you noticed any hand and wrist pain during childcare?’ (Meems et al, 2015). If they responded ‘yes’, participants were asked to select the childcare activity during which they noticed pain from the following options (Gomez et al, 2001):
- Lifting or holding the baby
- Breastfeeding
- Changing diapers
- Bathing the baby
- Putting the baby down to sleep
- Other.
Self-induced hand and wrist pain: Eichhoff's test
Eichhoff's test assesses arthrosis of the first carpometacarpal joint of the thumb and is considered the gold standard to diagnose de Quervain tenosynovitis (Saaiq, 2021). It is a stretching test for two tendons that induces pain on the tendon sheath of the styloid process of the radius, which results from the stretch of the extensor pollicis brevis and abductor pollicis longus when a subject firmly grabs the thumb with their other fingers and clenches the hand.
A preliminary survey of 26 postpartum women confirmed that self-assessment with Eichhoff's test was possible. After explaining the test procedure to participants using illustrations, they were able to conduct the test themselves. The illustrations of the process of Eichhoff's test were created by the researchers (Figure 1) and accompanied with the question: ‘do you feel any pain when you grab your thumb with your other fingers and bend it forward?’. Participants who answered ‘yes’ were categorised as having ‘induced pain’.
Upper extremity disability self-assessment: Hand20 (Japanese version)
The Hand20 questionnaire (NPO Hand Frontier, 2007) is a freely distributed 20-item self-report scale that consists of a compact structure of texts, illustrations and a visual analogue scale (Figure 2). It can be completed quickly, making it suitable for busy childrearing mothers. It is used to assess upper extremity disability resulting from hand and wrist pain. Its reliability and validity have been confirmed for the Japanese population; research using this scale for Japanese patients with upper extremity disability reported a Cronbach's coefficient alpha of 0.973, and 0.943 in a replicated re-examination and the correlation to the Disabilities of the Arm, Shoulder and Hand test (Japanese version) was 0.91 (Suzuki et al, 2010). Cronbach's alpha coefficients at 6 and 9 months were similar: 0.96–0.98. Thus, the Hand20 was selected to assess upper extremity function.
Participants indicated their condition, in terms of how pain restricted their daily activities, over the week before data collection on a 10-point Likert scale where 0 was ‘no activity limitation’ and 10 was ‘impossible to perform activity’. The cut-off value for Hand20 is 13.1 or more out of a possible total of 100, which is considered abnormal when referring to 75% of the value based on a survey of a healthy population as standard (Onishi et al, 2014). High scores indicated severe disability and participants scoring 13.1 or more were considered to have an upper extremity disability.
Self-assessed quality of life: EQ-5D-5L (Japanese version)
The EQ-5D-5L was used to measure health-related quality of life (Herdman et al, 2011). This instrument consisted of a 5-item scale, on which participants indicated ‘no problem’ or ‘cannot do it at all’ for five dimensions: mobility, self-care, usual activities, pain/discomfort and anxiety/depression.
A visual analogue scale was also used, on which participants evaluated their health condition on a thermometer-like line segment (0 being the worst and 100 being the best). The EQ-5D-5L visual analogue scale has been translated into several languages, including Japanese (Shiroiwa et al, 2016). Quality of life is calculated based on conversion tables created in several countries, wherein 1 represents best health and 0 represents worst health. Cronbach's alpha of the EQ-5D-5L (Japanese version) is reported to be 0.929 (Noto et al, 2017; EuroQol Research Foundation, 2019).
Data analysis
The statistical package for social sciences version 24 (SPSS, Chicago, IL, USA) was used for statistical analysis, and significance was set at 5% (two-sided).
Descriptive statistics were performed on the Hand20 and EQ-5D-5L data, and participants' demographic data, and normality was tested. Subsequently, the relationship between subjective and induced pain was investigated, as well as that between induced pain and upper extremity disability, using two types of Chi-squared test, the Pearson Chi-squared and the likelihood ratio Chi-squared tests. The latter was used to explore the probability of presenting with upper extremity disability. The difference in general quality of life between women with subjective and induced pain and those without was investigated using the t-test.
Ethical considerations
This study followed the principles outlined in the Declaration of Helsinki in 2001. Data collection began after the research protocol obtained the approval of the ethics committee of the Saga University Faculty of Medicine (Approval number 28-17).
The purpose of the study, activities involved, pain and discomfort, (such as self-induced pain), benefits, assurance of anonymity, confidentiality and ethical considerations (freedom of participation and the right to withdraw) were explained to all participants in writing and verbally before obtaining their written consent.
Results and discussion
Of the 190 women recruited 5 days after birth, 139 (73.2%) returned questionnaires and 131 (68.9%) consented to participate in the subsequent two surveys at 2 and 6 months. The mean age of participants was 31±6.2 years and 51.1% of the participants were first-time mothers. None had visited a medical institution or been diagnosed with upper extremity disability at the time of recruitment.
Subjective and induced hand and wrist pain
A total of 79 postpartum mothers (60.3%) reported hand and wrist pain at 2 months postpartum (Table 1). Although not all mothers who reported subjective pain had a positive Eichhoff's test, 11 mothers with no subjective pain tested positive for the self-induced pain test, increasing the incidence of hand and wrist pain in the group and showing the utility of different methods of assessment.
Table 1. Subjective hand and wrist pain during childcare and induced pain (n=131)
Induced pain | |||||||||
---|---|---|---|---|---|---|---|---|---|
2 months after birth | 6 months after birth | ||||||||
Total | Positive | Negative | P value | Total | Positive | Negative | P value | ||
Subjective pain | Yes | 79 | 42 | 37 | <0.001 | 45 | 27 | 18 | <0.001 |
No | 52 | 11 | 41 | 86 | 19 | 67 |
Mothers self-performed the Eichhoff's test to assess induced pain, and there was a significant association between subjectively assessed hand and wrist pain reported during childcare and induced pain (P<0.001). Table 1 shows the results of testing the relationship between subjective hand and wrist pain during childcare and induced pain 2 and 6 months after birth. However, 46.8% and 40.0% reported subjective pain, but not induced pain, at 2 and 6 months after birth respectively, and 21.2% and 22.1% did not report subjective pain but reported induced pain at 2 and 6 months after birth respectively.
Subjective and induced pain were significantly associated. However, among the participants who experienced subjective pain 2 and 6 months after birth, only 53.2% and 60.0% respectively reported induced pain at 2 and 6 months. This may be because of the specificity of Eichhoff's test, which is used to assess de Quervain tenosynovitis. Postpartum hand and wrist pain may originate in different parts of the hand articulation. For this reason, Jung et al (2021) indicated that hand and wrist pain cannot be assessed with only one test. It is for this reason that the present study's authors suggest the use of the self-induced test alongside the subjective pain report and a self-assessment questionnaire, such as the Hand20.
Hand and wrist pain and upper extremity disability
There was a significant association between subjective pain, induced pain and upper extremity disability. A total of 11 out of 42 (26.2%) postpartum women 2 months after birth and 11 of 27 (40.7%) women 6 months after presented with both subjective and induced pain and developed upper extremity disabilities. For the three types of pain (subjective, induced and both subjective and induced), the positive likelihood ratio was higher for postpartum women with subjective and induced pain both 2 and 6 months after birth. Therefore, it is reasonable to conclude that both subjective and induced pain are meaningful hand and wrist pain experienced by postpartum mothers. Table 2 shows the association between each type of pain and upper extremity disability.
Table 2. Subjective and induced hand and wrist pain and upper extremity disability (n=131)
Upper extremity function | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|
2 months after birth | 6 months after birth | |||||||||
Abnormal | Normal | Total | P value | Positive likelihood ratio | Abnormal | Normal | Total | P value | Positive likelihood ratio | |
Subjective pain | ||||||||||
Yes | 13 | 66 | 79 | 0.008 | 1.646 | 12 | 33 | 45 | <0.001 | 3.301 |
No | 1 | 51 | 52 | 1 | 85 | 86 | ||||
Induced pain | ||||||||||
Yes | 11 | 42 | 53 | 0.002 | 2.189 | 11 | 35 | 46 | <0.001 | 2.853 |
No | 3 | 75 | 78 | 2 | 83 | 85 | ||||
Subjective and induced pain | ||||||||||
Yes | 11 | 31 | 42 | <0.001 | 2.965 | 11 | 16 | 27 | <0.001 | 6.240 |
No | 3 | 86 | 89 | 2 | 102 | 104 |
The likelihood ratios of subjective pain, induced pain, and both subjective and induced pain were 1.646, 2.189, 2.965 respectively 2 months after birth and 3.307, 2.853, and 6.240 6 respectively 6 months after birth. Those who experienced both subjective and induced pain exhibited the highest scores. The higher the value of the positive likelihood ratio, the more likely the patient has the condition being studied. For instance, mothers who reported subjective pain at 2 months postpartum were 1.6 times more likely to present upper extremity disability and postpartum mothers reporting both subjective and induced pain were 2.9 times more likely to present the condition. This demonstrates the possibility of developing upper extremity disability and the importance of using multiple methods to assess hand and wrist pain.
Few previous studies have investigated upper extremity disability following hand and wrist pain in postpartum mothers. One randomised control study used the Disabilities of the Arm, Shoulder and Hand questionnaire to evaluate hand and wrist pain before and after two therapeutic interventions in 45 postpartum women. They found that wrist pain was significantly associated with quality of life; therapeutic interventions resulted in significant decrease of wrist pain and improvement of quality of life scores. (Jung et al, 2021). Physical problems such as pain are related to poor self-rated health and emotional wellbeing, and as their severity increases, postpartum women's functional limitation increase too, affecting the ability to work, do housework and provide childcare (Sit et al, 2017). The patient-rated wrist evaluation was not used in the present study, as the Hand20 questionnaire showed a greater Cronbach's alpha.
Hand and wrist pain and quality of life
Table 3 shows the association between subjective and induced pain 2 and 6 months postpartum and general quality of life. Participants with both subjective and induced pain 2 and 6 months after birth were found to have a significantly lower general quality of life (P<0.001 in both cases) than those without. The EQ-5D-5L scores of participants with subjective and induced pain (0.86 and 0.87, 2 and 6 months after birth respectively) were similar to the quality of life scores found in women after a caesarean section (EQ-5D-5L score: 0.85, 20–30 days after birth) (Kohler et al, 2018) and in postpartum women with a history of mental health problems 6 months after birth (EQ-5D-5L score: 0.85).
Table 3. Subjective and induced hand and wrist pain 2 and 6 months after birth and general quality of life (n=131)
Quality of life | |||||||
---|---|---|---|---|---|---|---|
2 months after birth | 6 months after birth | ||||||
n | EQ-5D-5L score | P value | n | EQ-5D-5L score | P value | ||
Subjective and induced pain (mean ± standard deviation) | Yes | 42 | 0.86 (0.09) | <0.001 | 27 | 0.87 (0.08) | <0.001 |
No | 89 | 0.92 (0.09) | 104 | 0.94 (0.08) |
Hand and wrist pain is disabling and lowers quality of life (Zychowics, 2013). Other conditions reported to lower the generic quality of life of postpartum women include lumbar and pelvic girdle pain (Gutke et al, 2011), postnatal depression (Zubaran and Foresti, 2011), mental health problems (Turkstra et al, 2013) and breastfeeding difficulties (Mortazavi et al, 2014). De Quervain tenosynovitis, a condition common among postpartum women (Gomez et al, 2001), has also been reported to lower the quality of life of adult men and women (Langer et al, 2015; Allbrook, 2019). These previous studies combined with the present study's results suggest that to improve the quality of life of postpartum women, hand and wrist pain should be promptly diagnosed and treated.
Course of upper extremity disability
The course of upper extremity disability was tested for its association with subjective and induced pain in 14 participants who were found to have upper extremity disability (Hand20 score>13.1) 2 months after birth (Table 4). In total, 11 first-time mothers (16.7%) had upper extremity disability 2 months after birth, while only three multiparous mothers did (4.5%). Seven participants with upper extremity disability reported both subjective and induced pain in the wrist. The upper extremity disability of five mothers (cases 1–5) continued after 6 months, and all had both subjective and induced pain. Two mothers (cases 1 and 2) reported that they still had upper extremity disability after 9 months. The five participants with upper extremity disability 6 months after birth were advised to see an orthopedic specialist. Two participants (cases 1 and 4) did not consider it necessary, and one (case 3) reported that they were too busy to go to the hospital. Two (cases 2 and 5) reported having been diagnosed with de Quervain tenosynovitis after seeing a specialist (Table 4).
Table 4. Course of upper extremity disability and subjective/induced pain in 14 cases 2–9 months after childbirth
Case | Age (years) | Parity | Hand20 score | Subjective/induced pain | Specialist advice | de Quervain tenosynovitis | |||||
---|---|---|---|---|---|---|---|---|---|---|---|
2 months | 6 months | 9 months | 2 months | 6 months | 9 months | Referred | Consulted | ||||
1 | 29 | P | 24.0 | 17.5 | 26.5 | + | + | + | Yes | No | NA |
2 | 41 | P | 18.0 | 15.0 | 15.0 | + | + | + | Yes | Yes | + |
3 | 26 | P | 48.5 | 32.5 | 9.5 | + | + | – | Yes | No | NA |
4 | 34 | P | 19.5 | 14.5 | NA | + | + | – | Yes | No | NA |
5 | 26 | P | 23.0 | 26.5 | NA | + | + | NA | Yes | Yes | + |
6 | 37 | P | 31.0 | 7.0 | NA | + | + | NA | NA | NA | NA |
7 | 34 | P | 28.0 | 8.5 | NA | + | + | NA | NA | NA | NA |
8 | 42 | P | 29.0 | 8.0 | NA | – | – | NA | NA | NA | NA |
9 | 33 | P | 16.0 | 0.0 | NA | + | – | NA | NA | NA | NA |
10 | 27 | P | 15.5 | 0.0 | NA | + | – | NA | NA | NA | NA |
11 | 28 | P | 15.0 | 0.0 | NA | + | – | NA | NA | NA | NA |
12 | 39 | M | 21.0 | 0.0 | NA | + | – | NA | NA | NA | NA |
13 | 35 | M | 15.5 | 7.0 | NA | – | – | NA | NA | NA | NA |
14 | 41 | M | 13.5 | 3.5 | NA | – | – | NA | NA | NA | NA |
Parity: P=primiparous, M=multiparous. Pain: +=presence, –=no pain, NA=not assessed
The course of upper extremity disability and subjective and induced pain in eight participants with newly developed upper extremity disability 6 months after birth was investigated (Table 5). Four (50.0%) were multiparous mothers, and seven (87.5%) (cases 15–21) had both subjective and induced pain. Nine months after birth, three mothers (37.5%) (cases 15, 16, and 20) still presented with upper extremity disability. All eight mothers were advised to consult an orthopedic specialist. Two (cases 15 and 16) saw specialists who diagnosed de Quervain tenosynovitis. Five (cases 17-21) did not consult with a specialist because they were busy or had no place to leave their children while they went to the hospital and one could not be found for follow up.
Table 5. Course of upper extremity disability and subjective and induced hand and wrist pain after birth
Case | Age (years) | Parity | Hand20 score | Subjective and induced pain | Specialist advice | de Quervain tenosynovitis | |||||
---|---|---|---|---|---|---|---|---|---|---|---|
2 months | 6 months | 9 months | 2 months | 6 months | 9 months | Referred | Consulted | ||||
15 | 32 | P | 9.0 | 49.5 | 24.0 | + | + | + | Yes | Yes | + |
16 | 30 | P | 2.5 | 18.0 | 27.5 | + | + | + | Yes | Yes | + |
17 | 30 | P | 4.0 | 35.5 | 1.0 | – | + | – | Yes | No | NA |
18 | 32 | P | 2.0 | 25.0 | 1.5 | – | + | – | Yes | No | NA |
19 | 30 | M | 1.0 | 43.5 | 0.0 | + | + | – | Yes | No | NA |
20 | 29 | M | 9.5 | 22.5 | 27.5 | – | + | + | Yes | No | NA |
21 | 40 | M | 4.0 | 15.0 | 4.5 | + | + | + | Yes | No | NA |
22 | 30 | M | 0.5 | 14.0 | NA | – | – | NA | Yes | NA | NA |
Parity: P=primiparous, M=multiparous. Pain: +=presence, –=no pain, NA=not assessed
In total, 22 (16.8%) postpartum women exhibited upper extremity disability 2 and 6 months after birth. Of these, 11 were followed up until 9 months after birth, revealing that upper extremity disability persisted in four mothers. Although upper extremity disability went into spontaneous remission for most participants in this study, some experienced hand and wrist pain that lowered their quality of life for several months and some developed long-term upper extremity disability.
The EQ-5D-5L scores (1–100 points) 6 months after birth were significantly lower for multiparous mothers (first-time mothers: 85.0±11.3 versus multiparous mothers: 78.1±16.4, P<0.01). Multiparous mothers have been found to be better at self-management and thus may not expect as much support (Schytt and Waldenström, 2007). However, those reporting hand and wrist pain 6 months after birth are in need of support, as indicated by the present study's results.
Hand and wrist pain and health-seeking behaviour
Health-seeking behaviour is defined as an individual's deeds in the promotion of maximum wellbeing, recovery and rehabilitation and has been found to be related to healthcare use among people who experience chronic pain (Poortaghi et al, 2015; Braeuninger-Weimer et al, 2021). None of the 13 mothers with upper extremity disability 6 months after birth consulted a medical institution, even after receiving advice to see a specialist. Postpartum women are busy and may be unwilling to consult a specialist even when they feel unwell (Wuytack et al, 2015). As such, few mothers may consult a medical institution about hand and wrist pain (Satoh et al, 2017; Sit et al, 2017). The health seeking behaviour of childrearing mothers suffering chronic pain needs particular attention.
Conclusions
In the present study, subjectively assessed hand and wrist pain, induced pain and both subjective and induced pain were significantly associated with self-reported upper extremity disability and lower general quality of life in postpartum mothers in Japan. However, it should be noted that only one, specific form of pain was assessed through a single test, and multiple pain self-assessment tools would be a better method to assess hand and wrist pain among postpartum women.
A subjective pain report and a self-induced pain test, such as Eichhoff's test, can help to identify hand and wrist pain among postpartum women. An easy to use self-report scale such as the Hand20 questionnaire confirms the presence of upper extremity disability and indicates the need to seek care to improve quality of life.
Implications for practice
Hand and wrist pain may lead to upper extremity disability, and self-assessment should be encouraged as early as 2 months after birth, meaning mothers should be instructed on hand and wrist pain assessment during pregnancy or shortly after birth. Although hand and wrist pain may resolve spontaneously, those affected may develop conditions such as de Quervain tenosynovitis, which will not become severe if diagnosed and treated early.
All mothers, regardless of parity, may develop hand and wrist pain. Midwives and other professionals caring for pregnant and postpartum mothers could provide preventive education, encourage self-assessment and monitor hand and wrist pain as childrearing mothers may be reluctant or unable to take time away from childrearing to take care of their own pain.
Key points
- Hand and wrist pain may present in the postpartum period as a result of repetitive use of the hands and wrists during childcare. Both first-time and experienced mothers may experience hand and wrist pain.
- Untreated hand and wrist pain can become chronic, causing disability of the upper limbs and affecting a mother's quality of life.
- There are several methods to self-assess hand and wrist pain at home. A self-induced pain test can be conducted in less than a minute and it takes less than 10 minutes to complete a self-reported 20-item illustrated questionnaire.
- Midwives can encourage mothers who are busy to self-report hand and wrist pain, or other pain, during the postpartum period and refer them to a specialist when necessary.
CPD reflective questions
- How aware are you of hand and wrist pain in postpartum mothers at your practice?
- Do you assess mothers for postpartum pain, including hand and wrist pain?
- How can breastfeeding mothers be advised to proceed when they present with hand and wrist pain?
- Is postpartum mothers' quality of life significantly affected by hand and wrist pain?
- Are antenatal education and patient information (videos, leaflets) useful to prevent hand and wrist pain?
- Are self-reporting and self-assessment of hand and wrist pain useful for healthcare professionals to consider in postpartum mothers?