Risk factors of pelvic organ prolapse in Iranian women: a cross-sectional study

INTRODUCTION

The POP risk factors include aging, vaginal delivery, trauma during delivery, increasing chronic intra-abdominal pressure conditions such as obesity, chronic constipation, chronic coughing, and repetitive heavy lifting, menopause, estrogen deficiency, genetic factors, smoking, prior surgery, myopathy and collagen abnormalities.⁴ POP is more common after the childbirth and menopause.⁵

The previous studies recognized parity as an important risk factor for development of POP.⁶ However, it is not known whether POP is attributed to parity or pregnancy itself. Some studies reported an associate prolapse with pelvic floor injury sustained during vaginal delivery and suggested cesarean delivery as a preventive factor decreasing the risk of POP.⁷ In a study, it has been shown that promoted life expectancy and the aging could increase the rate of urogenital prolapse, especially since the majority of women may spend one third of their lives in the postmenopausal state.⁸

Based on our knowledge, there is no adequate research to determine the prevalence and predisposing factors of the POP in Iran. So, this study was conducted to determine the risk factors of POP and the relationship between these risk factors and POP. Determining the factors can help to maternal care providers in order to prevent POP.

METHODS

This cross-sectional study was performed to examine the role of demographic, anthropometric and clinical variables in POP among women attending two public centres in Ilam province, Iran. All women participated in the research except for single, pregnant, lactate and women receiving hormone replacement therapy. Totally, in this study, 365 women participated. Data were collected and examinations were carried out in face to face interviews. The information had three parts:

1. Demographic information: Data on age, education, and occupation included.

2. Anthropometrics data: Information on weight and height were collected. Personnel measured the height and weight by a Seca 220 (made by Germany), while the participants were minimally clothed and not worn shoes. The body mass index was computed via this formula [BMI = weight (kg)/ height (m)²]. Based on the BMI, as recommended by the National Centre for Education in Maternal and Child Health, women were grouped into different categories.⁹

3. Clinical measures: The summary of the patient’s obstetrical included data on pregnancy, delivery mode, delivery operative, delivery position, maximum birth weight (MBW), medical and surgical histories and POP type and stage collected with observation, interview٫ and examination.

According to the Pelvic Organ Prolapse Quantification (POP-Q) technique, dorsal lithotomy position was evaluated in all subjects after emptying their bladders. Stages and position of prolapse were detected using the standardized system of the International Continence Society.¹⁰ In this system, sizes are made at different vaginal sites, providing eligible for prolapse affecting different vaginal segments (anterior and posterior vagina, vaginal apex or cervix) as well as a whole stage of prolapse. Sizes are measured in centimetres compared to the hymen as the reference point. In this system, negative numbers represent positions above the hymen, and positive numbers represent points beyond or past the hymen. A rigid marked hysterometer, calibrated in centimeteres was used for measurements. In addition, the small vaginal dilator was used to measure Aa, Ba, Ap‚ Bp. The apical points of C, D and the Total Vaginal Length (TVL) points were measured relative to the hymen. All points except for TVL were recorded in maximal valsalva effort. The external measurements of Genital Hiatus (GH) and Barometric Pressure (PB) created at the time of rest and with strain. Then, bimanual examination for determine abdominal and pelvic mass were performed. Patients were divided into two groups for comparison: (1) with prolapse (2) without prolapse. To indicate the association between dependent (with prolapse vs. without prolapse) and independent variables, both univariate and multiple logistic regression analyses were used. Independent variables tested for an association were age, education, occupation, body mass index, pregnancy, delivery mode, delivery operative, delivery position, and maximum birth weight. In this study, the Ethics Committee of Ilam University of Medical Sciences approved the study plan. After comprehensive explanation of the procedures involved, written informed consent was obtained from the participants.

RESULTS

Totally, 365 women participated in the vaginal examination. Since this study developed for assessing the pregnancy-related variables, 23 women excluded from analysis. Those women had not pregnancy yet. The mean age of participants was 36±9 years.

The results obtained from univariate logistic regression analysis indicated that there were significant differences in age, occupation, maximum birth weight, BMI, pregnancy, delivery mode, delivery operative and delivery position between women with and without prolapse. The results are shown in Table 1.

Table 1: The results obtained from univariate logistic regression analysis for Prolapse

CI: Confidence Interval; *Number (%);**Mean (SD).

However, when forward conditional based on multiple logistic regression analysis was performed, the results showed that age, normal vaginal delivery and Episiotomy emerged as significant factors for increased risk of prolapse (Table 2).

Table 2: Logistic regression analysis of factors associated with having prolapse

CI: Confidence Interval;*Adjusted for Occupation, Maximum Birth Weight, Body Mass Index, Pregnancy and Delivery operative; **Mean (SD).

DISCUSSION