Low back pain is the main complaint of musculoskeletal discomfort in pregnant women [1][2]. The exact cause of low back pain is poorly understood and is often considered multifactorial in nature, associated with biomechanical, vascular, and hormonal changes during pregnancy [3]. The most commonly assessed risk factors are a history of low back pain before pregnancy, a history of low back pain during or after a previous pregnancy, maternal height, weight, and age, and the number of previous pregnancies [4].

Low back pain is common and universal during pregnancy; it is reportedly more common compared to the general population [5]-[7]. It can occur at all stages of pregnancy, but is most common during the second trimester [8]. In sub-Saharan Africa, although some studies have addressed low back pain during pregnancy, few describe the factors associated with the occurrence of low back pain during pregnancy [3][9]-[11]. The lack of previous data on this subject in Guinea motivated this study, the objective of which was to determine the prevalence and factors associated with pregnancy-related low back pain.

This was a 6-month cross-sectional study (March 1 to August 31, 2023) in the obstetrics and gynaecology departments of the Ignace Deen University Hospital and the municipal medical center located in the municipality of Ratoma. The study concerned all pregnant women who consulted during the study period. We searched in this group pregnant women who suffered from low back pain with or without irradiation, regardless of the cause. The two groups were subsequently compared. We do not have in the study:

- Patients who have had low back pain before any pregnancy

- Patients with a history of spinal trauma or spinal surgery

A two-part survey form was used for data collection, and these data were collected while respecting patient anonymity:

- The first part: included sociodemographic variables (age in years, sex, marital status, educational level, geographical origin relating to the municipality of residence, occupation of the patient), clinical and paraclinical variables (mechanical or inflammatory low back pain, pain intensity, pelvic radicular pain, intermittent claudication, paraesthesia, mobility impairment assessed according to MRC scale, sensory disorder, duration of symptom development in acute stage (less than one month), subacute (between one and three months) and chronic (more than three months), body mass index; bell sign; Lasègue sign, paravertebral muscle contracture, sphincter disorders, comorbidities.

- The second part included pregnancy-related information: gravidity (which corresponds to the woman’s number of confirmed pregnancies), gestational age, and parity (which is the number of deliveries after 20 weeks of amenorrhea). For parity, we classified the women into primipara (a woman carrying her first pregnancy), multipara (a woman who has given birth multiple times), and grand multipara (a woman who has given birth multiple times without spacing out pregnancies). Pre-pregnancy history was sought.

We collected 708 pregnant women. The mean age of the pregnant women was 30.6 ± 7.3 years with extremes of 15 years and 51 years. Two hundred and forty-three (34.3%) of them had low back pain. Of the 243 women with low back pain, 38.7% were primigravidas. Eighty-seven (35.8%) pregnant women had a primary education level and 76 (31.2%) were not in school. Low back pain occurred during the first trimester of pregnancy in 29 (36.6%) pregnant women, in the second trimester in 125 (51.4%) and in the last trimester in 89 (36.6%) pregnant women (Table 1). The intensity of pain was moderate in 57 (23.4%) primiparas and 87 (35.8%) multiparas. Subacute low back pain was found in 35 (22.6%) multigravidas versus 24 (9.9%) primigravidas. The aggravating factor of the pain was postural in 226 (88.6%) of the pregnant women. Carrying weight aggravated low back pain in 129 multigravidas and in 86 primigravidas (Table 2). The factors associated with the occurrence of low back pain in pregnant women were age (p-value = 0.008) and the origin of the pregnant woman (p-value = 0.0008) (Table 3). No statistically significant difference was found between gestational age, the occurrence of low back pain during previous pregnancies, the number of children of the pregnant woman and the fact of being primigravida or multigravida (Table 4).

Table 1. Distribution of patients according to socio-demographic characteristics of pregnant women.

Table 2. Sociodemographic characteristics of pregnant women according to the presence or absence of low back pain.

Table 3. Clinical characteristics of low back pain in pregnant women according to gestation.

Table 4. Distribution of pregnant women with low back pain according to gestational characteristics.

We conducted this cross-sectional study on low back pain in pregnant women. We collected information directly from the patients. However, any interpretation of the data should take into account the study’s limitations. Our limitations and difficulties were related to the failure to perform certain laboratory and ultrasound assessments due to the precarious financial situation. Despite these limitations, the results of this study made it possible to describe the epidemiological and clinical characteristics of low back pain in pregnant women.

In our study, 708 pregnant women were interviewed, 243 (34.3%) of whom reported having low back pain during their pregnancies. Our results were similar to those of Omoke et al. [11] in 2021 in Nigeria, where the prevalence of low back pain was 28.9%. However, our data were lower than those of Manyozo et al. [3] in Brazil, where the prevalence of low back pain was 68%. The average age of the respondents was similar to that of Morino et al. [12] in Japan (25.8 years), Manyozo et al. [3] in Malawi (25.8 years), Hawker et al. [13] in South Africa (31 years) and Bryndal et al. [14] in Poland (31.8 years). This could be explained by the fact that they are the most active in housework. Housewives were the most affected. This was in agreement with the study of Hawker et al. [13] in South Africa. In our study, we have a predominance for a BMI of 25 - 29.9 = overweight, with a percentage of 51.1. This result is comparable to those of Hawker et al. [13] in 2021 in South Africa and Duarte et al. [5] in 2016 in Brazil who found respectively that 32.4% and 29.00% of women were overweight. The increase in body weight leads to a greater overload of the osteo-musculo-ligamentary structures of the lumbar region, predisposing to the appearance of symptoms in the pre-gestational period. During pregnancy, these symptoms can be aggravated due to an increase even greater of this overload due to the physiological changes in the lumbar region. Indeed, in our country, the work of a housewife requires considerable physical activity such as washing clothes, carrying the bucket by hand, drawing water by hand, cleaning the floor, and carrying the child on the back.

While in developed countries, housework is being replaced by machines like washing machines, vacuum cleaners, etc. The arduous nature of domestic work places a heavy strain on the back. The predominance of married women was similar to that of Carvalho et al. in 2016 in Brazil (86.6%) and Duarte et al. in Brazil [2][5] (58.8%), who reported in their study that married women are the most affected. In contrast, Hawker et al. [13] in South Africa found that 82% of women were single. Married status is thought to increase social support with health benefits, and to reduce stress related to social and financial life situations.

The occurrence of low back pain, primarily during the second and third trimesters of pregnancy in this study, was similar to that of most published reports. In the study by Carvalho et al. [2], in Brazil, 43.24% of pregnant women reported that low back pain began in the 2nd trimester. Also, Manyozo et al. [3] found that women in their second (43%) and third trimesters (49%) were more likely to report low back pain compared to those in the first trimester (8%). This could be explained by the fact that the development of the fetus tends to compress the intra-abdominal organs and the spine. In our study, although the majority of cases were presented during the second trimester, the difference between the trimesters was not significant.

Low back pain was felt at any time without a specific time with moderate to severe intensity and in the majority of patients. These results were different from the data of Omoke et al. [11], in which the average pain intensity was mild (30.4%) and moderate (63.0%). They also found that the aggravating factors were mainly orthostatic posture (51.37%) and load carrying (23.9%), intense physical work and postural and intense work (2.9%). For the occurrence of low back pain in the 2nd and 3rd trimester, Wang et al. [15] indicated that low back pain mainly occurs during the first 5 to 7 months of pregnancy. Low back pain can be present at any time during pregnancy. The difference could be explained by the fact that the reported pain intensity is a reflection of the subjectivity of pain and sociocultural circumstances. They affect the adaptation and perception of low back pain during pregnancy. The treatment of low back pain in pregnant women in our context is based on psychological support, the use of paracetamol, physiotherapy and maintenance of activities

Low back pain, common and occurring mostly in the second trimester of pregnancy, had a gradual onset and was moderate to severe in intensity. Given the prevalence and clinical importance during pregnancy, health workers should be proactive in asking women about their experiences of low back pain in order to provide the necessary clinical care for their pain. These measures will go through the screening of low back pain and provide advice on postural changes, avoiding wearing a burden and a sedentary lifestyle.