UI is both a medical and a psychosocial problem. It is estimated that over 200 million women worldwide suffer from UI [1] . These figures are certainly underestimates, as more than half of all women prefer not to talk about their symptoms due to the taboo nature of the condition [2] .

The risk of UTI increases considerably during pregnancy [3] . According to Brown et al. [3] , the risk of UTI is the highest in the third trimester of pregnancy. The prevalence of UTI during pregnancy varies between 21.1% and 71% according to the literature [4] - [6] .

The few studies carried out in sub-Saharan Africa report a prevalence of 11.4% in Ethiopia [7] , 28.1% in Nigeria [8] and 43.03% in Benin [9] . Overall, this seems lower than the prevalences reported in developed countries.

The most common type of urinary incontinence during pregnancy is stress incontinence [3] [6] [10] . Hormonal changes, increased intra-abdominal pressure and the pressure exerted by the uterus on the bladder and pelvic floor during pregnancy are factors that favour the development of stress urinary incontinence (SUI) [11] - [13] . In Nigeria Okunola and al found that age, body mass index, parity and vaginal delivery have been reported [14] . According to Dinç in Türkiye, SUI after delivery was related to the mother’s history of SUI before pregnancy (PR 2.4) and during pregnancy (PR 2.0), as well as having undergone vaginal delivery (PR 2.0) [11] .

In our daily practice, pregnant women rarely complain of UTI during prenatal consultations. To our knowledge, this is the first study of UTI in pregnant women in Burkina Faso. The aim of the present study was to determine the prevalence of UTI during pregnancy and to identify the risk factors associated with this condition in order to improve its management.

We conducted a cross-sectional, analytical observational study from May 1 to August 30, 2023.

The study population consisted of all pregnant women attending antenatal consultations.

The study was multicentric and involved six public health facilities in the town of Ouahigouya. These were the Centre Social et de Promotion de Soins (CSPS) of Zoodo, Naba and Gourga, the Centres médicaux (CM) of Kapalin and Lazaret, and the gynecology-obstetrics department of the CHUR of Ouahigouya.

We included in this study all pregnant women fulfilling the following criteria:

Random sampling was used. The sample size was estimated on the basis of data published by Berhe et al. in Ethiopia [15] , who reported a prevalence of 23% for UTI during pregnancy. Considering a precision α = 0.05 and a study power of 90%, and using OpenEpi software, the sample size was estimated at 273 for a cross-sectional study. To compensate for possible non-responses, the size of our sample was increased by 20% (n = 328), which increases its power.

The number of pregnant women to be surveyed in each of the six health facilities was estimated from the proportion of pregnant women who consulted for their first prenatal consultation during the year 2022.

An interview with the women and a literature review were used for data collection.

Data were entered on a microcomputer and analyzed using Statistical Package for Social Science (SPSS) version 20.0 (SPSS Inc., Chicago, IL).

Modalities of each qualitative variable were presented in terms of frequency and percentage, and quantitative variables in terms of mean, standard deviation (SD), minimum value (min) and maximum value (max). A binary logistic regression model was used to assess the association between each explanatory variable and the variable of interest.

The study was carried out with the consent of the pregnant women. Anonymity was respected.

Informed consent was obtained from the pregnant women before the interview, and the anonymity of the questionnaires was preserved.

Of 328 women surveyed, 129 presented with urinary incontinence, representing a prevalence of 39.3% (129/328).

Limitations and constraints of the study:

The overall prevalence of UTI in pregnant women in the present study was 39.3%. This prevalence is similar to that reported by some African authors in previous studies. Houeto et al. [16] in Benin, Abdullah et al. [17] in Nigeria and Rajavuori et al. [18] in Finland reported a prevalence of 43.03%, 34.3% and 39.5% respectively.

On the other hand, our prevalence is significantly higher than those reported by Bekele et al. [7] in Ethiopia and Adaji et al. [19] in Nigeria, who reported a prevalence of 11.4% and 21.1% respectively. Higher prevalences were reported by Wang et al. [20] in China, Moossdorff-Steinhauser et al. [21] , Mohd Yusoff et al. [22] in Malaysia and Barbosa et al. [23] in Brazil, who found a prevalence of 52%, 41%, 84.5% and 55% respectively.

Generally speaking, the prevalence of UTIs varies from one study to another, from one country to another, and within the same country from one author to another, from one year to another. Several factors may explain this difference in prevalence from one country to another, and from one study to another the nature of the population studied, sometimes with very different samples (age and sample size).

In the present study, stress UTI accounted for 55% of all types of UTI. This result is in agreement with those of Moossdorff-Steinhauser et al. [21] and Berhe al [15] in Ethiopia, who found 63% and 58.9% respectively.

However, other authors have found results contrary to our own. This is the case of Santini et al. [24] in Brazil, who reported a predominance of mixed UTI.

Our result could be explained by hormonal factors and physiological change during pregnancy, in addition to existing genetic structures [25] . A possible reason could also be an increase in intra-abdominal pressure during sneezing, coughing and laughing; as a result, internal pressure on the bladder exceeds that of urethral closure, leading to urine leakage [15] .

In the present study, more than half the women (51.2%) had small drops during bladder leakage. Over 81% of women did not wear pads, and 78.3% had a frequency of urine loss of more than once a week. These different parameters show that moderate UI was the most dominant form. Nevertheless, this study showed that nearly 60% of incontinent women had a social limitation. Authors such as Hansen et al. [26] and Martinez et al. [27] reported moderate urine loss in 90 and 83.1% respectively.

The severity of UI is assessed differently in the literature. Some studies have assessed the severity of UI according to clinical characteristics (quantity and frequency of urine leakage). This is the case of Sangsawanga et al. [28] ; others, on the other hand, have based their assessment of the severity of UI on the impact it has on the quality of life of incontinent women (psychosocial discomfort, discomfort with daily activities, discomfort with sexual activity) [29] .

Risk factors for urinary incontinence during pregnancy.

Our study showed that vaginal delivery (p = 0.001; OR = 17.6) and caesarean section (p = 0.002; OR = 5.2) are strong independent risk factors for UI during pregnancy. Oliviera et al. [6] in Brazil reported that vaginal delivery increased the risk of UTI in pregnancy by 2.5 compared with caesarean section. Santini et al. [24] reported that Caesarean section increased the risk of UTI by 2.5 times in their Brazilian study.

This is because vaginal delivery causes distension of the pelvic floor ligaments. This can weaken the urethral sphincter, leading to SUI.

Wang et al. in China [20] reported that Caesarean section showed no protective or aggravating effect in their studies.

There is a correlation between BMI and the risk of UTI during pregnancy (p = 0.006). Pregnant women with a BMI greater than or equal to 25 kg/m² are 2 times more likely to develop UTI. The risk of UTI increases with a woman’s weight. Other authors such as Wesnes et al. [30] have reported similar results.

One possible explanation is that obesity creates tension on the pelvic floor due to increased intra-abdominal pressure. This could lead to pressure on the bladder, altering blood flow and innervation to the bladder and urethra. However, Abdullah et al. [17] found that BMI was not significantly associated with UI during pregnancy, and had no clear explanation for this finding.

The third trimester of pregnancy is an independent risk factor for UTI (OR = 2). Our result is similar to that reported by Kok et al. [31] . They found no significant difference between the first and third trimesters in terms of risk of UTI. However, they did note that the risk was multiplied by 3 in the third trimester compared with the first trimester.

In fact, the possible reason could be due to the increase in uterine and fetal weight during the progression to the third trimester, thus contributing to an increase in arterial pressure on the bladder and reduced bladder capacity. This can lead to bladder weakness during pregnancy [20] . Also, the weight of the fetus and its appendages increases pressure on the bladder and pelvic floor. The combination of these factors can lead to UI in the third trimester of pregnancy [23] .

On the other hand, other authors such as Kocaöz et al. found no correlation between trimester of pregnancy and the occurrence of UTI [4] .

Coffee consumption was an independent risk factor for UTI during pregnancy (p = 0.001; OR = 4.5 [2.6; 7.7]). Some authors have reported similar results. Tingthong et al. in Thailand [32] found a 3-fold increase in the risk of UTI in pregnant women who consumed coffee, and Wang et al. [20] also reported a 1.7-fold increase. According to the latter, caffeine could contract the bladder in advance, contributing to the occurrence of UTI during pregnancy.

However, Abdullah et al. [17] in Malaysia concluded that there was no significant association between coffee consumption and UTI. Okunola et al. in Nigeria [8] also found no significant association between coffee consumption and the risk of UTI during pregnancy. Mohd Yusoff et al. [22] even found that coffee consumption was a protective factor against the risk of UTI during pregnancy.

In fact, caffeine is thought to have a direct effect on the smooth muscle of the bladder. It can irritate the bladder tissue and potentially cause involuntary bladder contraction. It may thus contribute to urge incontinence.

The study showed a high prevalence of urinary incontinence in pregnant women. The taboo nature of this condition masks the socio-professional embarrassment it causes, making it difficult both to determine its true prevalence and to encourage women to talk to their doctor about it. To achieve this, the presence of bladder weakness should be systematically sought during prenatal consultations.

This study identified five independent risk factors for urinary incontinence in pregnant women. These were a history of vaginal delivery, a history of caesarean section, coffee consumption, second trimester of pregnancy and body mass index. Reducing coffee consumption, one of the two modifiable risk factors in this study, could therefore reduce the risk of urinary incontinence during pregnancy.