European Journal of Obstetrics & Gynecology and Reproductive Biology
ReviewRisk factors for the development of stress urinary incontinence during pregnancy in primigravidae: a review of the literature
Introduction
Stress urinary incontinence (SUI), the most common type of urinary incontinence (UI) in pregnant women, is defined by the International Continence Society (ICS) as the complaint of involuntary loss of urine on effort or physical exertion, or on sneezing or coughing [1]. The prevalence of SUI has been found in the range from 18.6% to 75% [2], increases with gestational age [3], [4] and is typically worst in the third trimester followed by second and first trimester, respectively [3], [5], [6].
Pregnancy is one of the main risk factors for the development of SUI in young women [7], [8]. Pregnancy may be associated with the reduction of the pelvic floor muscle (PFM) strength which may lead to reduced strength and supportive and sphincteric function of the PFM which can develop the SUI. However, the exact mechanism of pregnancy-related SUI is not well understood [9].
The PFM plays an integral role in the maintenance of the continence mechanism by actively supporting the pelvic organs, and closing the urethral sphincter when contracting [10]. When coughing, sneezing, laughing or moving, the intra-abdominal pressure increases and this pressure is transmitted to the bladder. When the pressure inside the bladder is greater than the urethral closure pressure incorporated with the weakness of the urethral sphincter, this results in urine leakage or SUI [2]. Studies in pregnant women with SUI have found significantly decreased PFM strength in incontinent pregnant women as compared to continent pregnant women [11].
However, SUI in women during pregnancy can be prevented and improved by pelvic floor muscle exercise (PFME). PFME is aimed at improving the PFM strength to support the bladder, bladder neck and urethra, increasing the efficacy of the sphincteric function of the urethra during exertion, and improving the continence mechanism after correct contraction of the pelvic floor [12], [13], [14]. Oliveira et al. [15] reported that the PFME resulted in a significant increase in PFM pressure and strength during pregnancy. Therefore, the PFME is recommended as the first intervention to prevent and improve SUI symptoms during pregnancy and postpartum before consideration of other interventions [16]. A Cochrane review concluded that the PFME is effective in preventing and reducing SUI in women during pregnancy and after delivery [17].
Epidemiological studies on the UI during pregnancy show various variable factors associated with UI. Some risk factors like race, chronic diseases, and fetal size are non-modifiable risk factors. However, several risk factors are modifiable and might be promoted to prevent UI during pregnancy [18].
This review discusses the risk factors for the development of SUI in pregnant women. However, the physiological changes and hormonal changes that lead to SUI in pregnancy have not been discussed in this review. They have been addressed in previous publication by the same author [2]. The purposes of this review are to explain the risk factors leading to SUI in primigravidae women and to review the randomized controlled trials (RCT) of preventing SUI during pregnancy. The understanding of these risk factors and preventing methods can be useful for health professionals in informing and advising the pregnant women to prevent and avoid several modifiable risk factors that contributing to the development of SUI during pregnancy.
Section snippets
Materials and methods
The researcher conducted a MEDLINE search for English-language and human study articles registered from January 1990 to September 2013. The researcher used the following search terms: “risk factor”, “age”, “obesity”, “smoking”, “constipation”, “pre-pregnancy stress urinary incontinence”, “gestational diabetes mellitus”, “pelvic floor muscle exercise”, “pelvic floor muscle training”, “urinary incontinence”, “stress urinary incontinence”, “pregnancy” and “pregnant women”.
The conference proceeding
Factors increasing the risk of developing SUI among pregnant women
Multiple factors have been found to be associated with the development of SUI during pregnancy, including the following (Table 1).
Discussion
To our knowledge, this is the first review of the literatures that described the risk factors to develop SUI during pregnancy. The most common type of UI in pregnant women is SUI. It is well known that pregnancy may associate with the reduction of the PFM strength which can develop the SUI. However, the exact mechanism of the development of SUI during pregnancy is remained unclear [9]. It has been proposed that SUI is caused by both mechanical and hormonal changes [21]. The anatomical and
Conclusions
PFM function is the main supportive mechanism of urinary continence. Reducing PFM strength both supportive and sphincteric functions of PFM which can develop the SUI. When intra-abdominal pressure is increased, urinary leakage will be the result.
Many modifiable and non-modifiable risk factors are identified, although some are less clear. The risks contribute to the effects of the major supportive mechanism of the bladder and PFM. Although non-modifiable, genetic and obstetric risk factors such
Acknowledgement
The authors would like to thank Dr. Denchai Laiwattana, M.D. for valuable criticism of the manuscript.
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