Prevalence of low back pain and interference with quality of life of pregnant women

BACKGROUND AND OBJECTIVES: Pregnancy is characterized by a period when women’s body suffers different changes. Between 50 and 80% of pregnant women refer low back pain, which may directly interfere with their quality of life. This study aimed at determining the prevalence of low back pain and its interference with quality of life of pregnant women assisted in the Family Health Strategy of the City of Cabo Frio. METHODS: Field cross-sectional study with pregnant women between the 13th and 36th week of gestation, with low back pain, assisted in a low risk pre-natal program. A demographic questionnaire, Roland Morris and WHOQOL-bref questionnaires were applied to evaluate low back pain and quality of life, respectively. Descriptive statistics and Spearman correlation tests were used and p<0.05 was considered statistically significant. RESULTS: Participated in the study 139 pregnant women assisted by the pre-natal assistance program. Mean age of 24.4±7.65 years. There has been significant correlation between quality of life domains questionnaire (physical domain p<0.000, psychological domain p<0.004, environmental domain p<0.022; social relations domain p<0.0025 and overall quality of life p< 0.000) and Roland Morris questionnaire. There has been correlation between weeks of gestation and Roland Morris questionnaire (p<0.005). As to weeks of gestation and quality of life questionnaire there has only been correlation in the social relation domain (p<0.025). CONCLUSION: Low back pain interferes with quality of life of studied pregnant women.


INTRODUCTION
Pregnancy is characterized by a period in which the woman's organism undergoes several hormonal, metabolic and musculoskeletal changes to adapt the body to her new condition of pregnant woman 1 .Changes during pregnancy are visible, like weight gain, fluid accumulation, breasts enlargement, abdominal circumference enlargement, greater anterior pelvic tilt and greater joint instability 2 .Therefore, approximately 50 to 80% of pregnant women report pain in the low back region at some moment during pregnancy 3 .Low back pain complaints are also related to other factors, such as postural changes, which are often factors responsible for ge-nerating an irregular biomechanical and compensatory process.In the period between the 13 th and 36 th week of pregnancy, the woman begins to change her ambulation, which changes the center of gravity, causing an overload on muscles and ligaments.As a result, there may be a degree of discomfort, causing partial or total impairment for daily activities 4 .Low back pain means a symptom of pain, located between the lower region of the last coastal arc and the gluteal fold, that may radiate to the lower limbs.If not properly treated, it can preclude a pregnant woman from having a normal life, causing insomnia, depression, functional disability, and may interfere directly with her quality of life (QOL) 5.6 .QOL is defined as an individual's understanding in the face of his/her socio-cultural life condition, considering their expectations, objectives, standards and responsibilities.The personal well-being is related to aspects of personal fulfillment, habits, health, lifestyle and leisure and is related to the conditions of the individual's way of life 7.8 .The Family Health Program (Programa Saúde da Família -PSF) was created in 1994, as a strategy of the Ministério da Saúde (MS) to redirect the care model of the Unified Health System (Sistema Único e Saúde -SUS), from the basic care approach 9 .In 2006, the PSF was called the Family Health Strategy (Estratégia da Saúde da Família -ESF) and aimed to expand people's access to healthcare services, providing full service, encouraging popular participation and creating intersectoral partnerships 10 .ESF is composed of a multidisciplinary team, with the goal of favoring a greater advance to the health of the population, developing a relationship of co-responsibility with the professionals of the sector, simplifying the identification and the solution of the community's health problems 11.12 .The Family Health Support Centers (Núcleos de Apoio à Saúde da Família -NASF) aim to expand basic care actions, provide broader assistance, have better results and full individual service to SUS, identifying the needs of each person in their territory of basic care, supporting ESF and increasing the responsibility of community health agents (Agentes Comunitários de Saúde -ACS) in creating links between the community and the healthcare system 13 .NASF is composed of professionals from different health fields, and their actions are based on reciprocity of experiences and knowledge, through technical support and pedagogical practices of the teams relevant to the selected population 14 .The inclusion of physiotherapy in basic care is a recent fact 15 .The physiotherapist develops different actions in basic care.One of these actions is to work with groups of pregnant women.In this setting, they learn about body postures, stretching exercises, relaxation, aid to venous return, breathing exercises and incentives to breastfeeding and baby care guidelines 16 .Based on actions for disease prevention and health promotion, and when necessary, refer to the secondary and tertiary care services 17 .Based on the presented assumption, it turns out that low back pain is an important cause of disability that impacts the QOL of pregnant women.Based on the above, the objective of this study was to determine the prevalence of low back pain, and its impact on the QOL of pregnant women cared for in the ESF of the municipality of Cabo Frio.

METHODS
Field cross-sectional study, with data collection held in the 1 st District of the city of Cabo Frio, specifically in the primary care network registered at DATASUS.The total number of pregnant women registered in this district was 267 patients.In this way, the sample size was estimated in an amount exceeding 20% of the population, since this size is enough to represent the population 18 .However, after visiting the participating units, the sample size was greater than this value (52% of all pregnant women).Thus, the sample was composed of women in their gestational period participating in the low-risk prenatal care program.The inclusion criteria were pregnant women in the 13 th to 36 th week of gestation, with a report of low back pain (LBP), literate and oriented as to time and place.The exclusion criteria were a history of fracture, spine surgery, gynecological and urinary diseases, amputations, mental disability, and non-attendance to the interview.Pregnant women who were awaiting the prenatal appointment were informed about the purpose of the study and invited to participate.Pregnant women who agreed to participate in the study signed an Free and Informed Consent Term (FICT) as provided for in resolution 466/12.In order to obtain the socio-demographic data, it was used a structured questionnaire, prepared by the researchers, with questions about weeks of gestation, age, race, marital status, education and profession/occupation of every pregnant woman.To evaluate functional impairment of the individual with low back pain, we used the Roland Morris Disability Questionnaire (RMDQ), validated in Brazil in 2001 19 .The questionnaire is easy to apply and used in evaluations of low back pain.It consists of 24 closed self--report questions, the sum of the yes answers given by the individual can be from zero to 24, being zero without complaints and 24 the maximum value, which represents more severe limitations 20.21 .To finalize data collection pregnant women were subjected to the WHOQOL-bref, a short questionnaire of quick application, validated in Brazil in 2006.It consists of four QOL domains.The purpose of each domain is to verify the physical domain (DomFis) -seven questions, psychological domain (DomPsic) -six questions, social relationships domain (DomRS) -three questions and the environmental domain (DomMA) -eight questions, totaling 24 questions and two more questions about global QOL.Assessment scores are calculated for each of the four domains.The minimum value of the scores for each domain is four and the maximum twenty.The score of each domain is obtained on a positive scale, that is, the higher the score, the better the QOL in that domain 22.23 .The study was authorized by the City Department of Health of Cabo Frio and accepted by the Ethics and Research Committee of the Universidade Estácio de Sá, with CAAE registry number 47922515.1.0000.5284.

Statistical analysis
Data were handled by the software SPSS Statistics 20 for Windows and presented as mean, standard deviation, minimum and maximum values and absolute and relative frequencies.The Spearman correlation test was used to verify the possible associations  The average age of pregnant women was 24.4±5.88years, being the youngest 13 years old and the oldest 41.As for gestation period, the average was 24.3±7.65 weeks.
Table 1 shows a higher number of Pardo Brazilians (mixed-race), pregnant women.There is a balance between single and married women and with elementary and high school educational level.
It should be noted that most of these pregnant women do not have professional activity.Figure 1 Refers to the number of pregnant women who were included in this study.Notice that Manoel Corrêa, Jacaré, and Tangará Health Centers have the highest number of registered pregnant women since they are the most populous neighborhoods in the city of Cabo Frio.
In the QOL questionnaire, there was uniformity among the respondents.The lowest score was in the physical domain, and all domains showed a satisfactory score (Table 2).
Observing table 3 we see that there is a significant correlation between the analyzed variables, except for weeks of gestation, with the physical, psychological and general QOL domains.
between the variables low back pain, time of gestation and QOL of pregnant women.The value of p<0.05 was considered statistically significant.

RESULTS
Of the 17 units visited, one had no pregnant women registered and, at one unit, pregnant women did not turn up on the day of the interview.Thus, 15 units took part in the study.In these 15 units, 267 pregnant women were registered, of which 9 did not accept to participate in the survey, 50 pregnant women were in the exclusion criteria, 69 did not show up on the days of the interview, leaving 139 that were included in the study.

DISCUSSION
In this study, we could see that low back pain interferes negatively on the QOL of pregnant women, and in all domains of the WHOQOL bref questionnaire.
In a performed study 24 , half of the pregnant women reported that the intensity of pain increased as weeks went by, especially between the 8 th and the 9 th months, with a range between 'little pain' and 'reasonable pain.'At the 7 th month of pregnancy (week 29 th ) the uterus of the woman enlarges, producing peaks of pain due to the overload on the lumbar spine, but according to another study 23 , the scale can remain between 'little pain' and 'reasonable pain.'In this study, however, as the gestational period progressed, pain intensity increased.
In a previous study 25 on low back pain in pregnant women, it was used the epidemiological questionnaire, validated and adapted from the Quebec Back Pain Disability Scale (QBPDS) to assess the level of functional impairment of pregnant women, emphasizing questions about LBP in the gestation period.
The result shows that the pain interferes with the daily life of pregnant women, causing some limitations in their activities.
In this study, however, it was used the RM questionnaire to evaluate functional impairment of pregnant women, obtaining the same result.It is believed that the prevalence of painful symptoms in the lower back region is still present in this segment of the population in the gestation period and, depending on the degree of pain, it can persist a few years after delivery if treatment is not provided 26 .In this regard, treatment and guidelines for four weeks during the pregnancy period proved to be effective to improve the functionality of pregnant women 27 .
In a study 28 with 21 pregnant women to determine the presence of pain and the types of LBP in a health unit in the city of Petrolina, the authors observed that 92.23% of pregnant women had LBP during pregnancy and, in 66.65% of the cases a combination of LBP and pelvic pain.In another paper 29 of similar design, 45 pregnant women assisted in a Prenatal Program, were evalu-ated using a numerical visual scale of pain.The results showed that the prevalence of LBP was 73%.In both studies, the characteristics of the sample were similar to those of this current work.Despite no specific test to determine pain having been applied, Roland Morris questionnaire is a valid measure of good reliability for chronic pain in the Brazilian population 30 .In some units, not 100% of the sample was surveyed.Many pregnant women were impatient and uncomfortable about the size of the questionnaires and intimate questions about their life.

CONCLUSION
From the results found in this study, we notice that in the group of pregnant women of the Health Units of the city of Cabo Frio, there is a correlation between the LBP and general QOL.

Figure 1 .
Figure 1.Health Units included in the study and number of pregnant women in each unit

Table 2 .
Descriptive analysis of the study variables DomFis = physical domain; DomPsic = psychological domain; DomRS = social relationship domain; DomMA = environmental domain; General QOV = general quality of life.