adenomyosis can be accompanied by pelvic pain , menorrhagia , dysmenorrhea , dyspareunia , painful menstrual cycles , and infertility . however , painful menstrual cycles and infertility are less common in these individuals , and about 35% of them are asymptomatic . diagnosis of this disease is often done through pathology and histology after hysterectomy ( 1 , 2 , 46 , 8 , 10 ) . this incidence of this disease has been reported in in the range of 8.8 to 61.5% of women who had hysterectomies ( 2 ) . several studies have indicated that various factors influence adenomyosis , including previous caesarian section , dilation and curettage ( d&c ) , dilation and evacuation ( d&e ) , spontaneous abortion , endometrial hyperplasia , menarche age , and gravidity . however , the results obtained for the comparative effects of the various risk factors were different ( 14 , 6 ) . in a study on the incidence and investigation of risk factors of adenomyosis in denmark , researchers examined 549 patients and concluded that the incidence of adenomyosis varied from 10 to 18% according to different criteria and that there was no significant relationship between adenomyosis and uterine surgery , such as previous caesarean section , myomectomy , dilation and curettage ( d&c ) , dilation and evacuation ( d&e ) ( 2 ) . another study ( 2004 ) investigated pathology species of 873 patients , and the results indicated that 41.7% of patients had adenomyosis . in this study , no significant relationship was found between adenomyosis and experiences of uterine surgery , such as previous caesarean section , myomectomy , dilation and curettage ( d&c ) , and dilation and evacuation ( d&e ) ; however , experience of uterine surgery ( caesarian section , myomectomy , d&c , and d&e ) is one of the most common factors associated with the incidence of adenomyosis ( 2 ) . in most cases , adenomyosis is asymptomatic in patients and is only diagnosed after hysterectomy ( 12 ) . effective medical treatment has been not introduced for adenomyosis , and some treatments only partially reduce symptoms in patients ( 13 ) . the reported prevalence of adenomyosis has varied significantly among the various studies ( 12 , 1416 ) . also , there is little agreement among the studies concerning the relationship between previous surgery and the incidence of adenomyosis . some reports indicated that there was a strong relationship between previous cesarean section and the incidence of adenomyosis , but others reported no such relationship ( 1 , 2 , 11 , and 14 ) . in iran , where the prevalence of adenomyosis has been reported to be 31.3% , a study was conducted in which researchers examined 41 cases of adenomyosis , and they found that 97% of the patients in the study had undergone a previous cesarean section ( 17 ) . due to the different reports from many parts of the world and the controversy about the risk factors for adenomyosis , we focused our study on the potential relationship between prior uterine surgery and the subsequent incidence of adenomyosis . in this retrospective , cross - sectional study , the data that were necessary for the investigation and analyses were obtained from files of patients who had been hospitalized in the shariati hospital in bandar - abbas , iran , from 2001 through 2011 . in this cross - sectional study , we reviewed the medical records of all women who underwent hysterectomies for benign and non - emergency gynecological conditions this time period . all patients who had a hysterectomy for benign uterine reasons and had positive specimens for pathology were investigated . exclusion criteria of the study included women in whom endometriosis and uterine malignancies were reported in their pathology . the reason they were excluded was that the aim was to study adenomyosis ; therefore , other uterine malignancies were omitted from the study . in order to obtain information on the variables , such as age , gravidity , parity , spontaneous abortion , uterine size according to pelvic examination , experiences of prior hysterectomy , prior uterine surgery , caesarian section , myomectomy , and dilation and curettage ( d&c ) , we referred to the patients files at the shariati hospital in bandar - abbas . in addition , other data , including uterine weight , uterine leiomyoma , and pathologic reports also were obtained from the patients files . this study was approved by ethics committee of hormozgan university of medical sciences , and the confidentiality of the data in the patients files was protected at all times . the data were analyzed by using spss version 16 ( spss , inc . , chicago , il , united states ) , descriptive statistics , the student s t - test , and analysis of variance ( anova ) . in this study , we investigated 201 women who had hysterectomies at the shariati hospital in bandar - abbas from 2001 through 2011 . ten patients were excluded from the study because of incomplete files , so we evaluated 191 patients . the average age of the patients was 51.6612.46 ( ranging from 23 to 85 ) , and the average of the age of patients who had positive pathology was 50.29.6 , while it was 52.5213.8 for those with negative pathology . the student s t - test indicated that there was no statistically significant difference between the patients mean ages and adenomyosis ( p = 0.07 ) . also , the findings of the study indicated that there was not a significant relationship between menarche age and adenomyosis prevalence ( p = 0.75 ) . in addition , the relationship between gravidity and the prevalence of adenomyosis was not statistically significant ( p = 0.7 ) ( table 1 ) . also , no significant relationship was found between parity and adenomyosis prevalence ( p = 0.78 ) . furthermore , there was no significant relationship between uterine size and increased risk of adenomyosis ( p = 0.82 ) ( table 1 ) . in addition , the relationship between rate of abortion and adenomyosis was not statistically significant ( p = 0.74 ) ( table 1 ) . among the 191 patients that we studied , 117 cases ( 61.3% ) had not a history of previous uterine surgery . of the 74 patients ( 38.7% ) with a history of previous uterine surgery , 18 patients ( 9.2% ) had experienced caesarian section ( c / s ) , of which 5 patients ( 2.6% ) had experienced both dilation and curettage ( d&c ) and c / s . with regard to adenomyosis , 72 patients ( 37.7% ) were pathologically positive and 119 patients ( 62.3 percent ) were pathologically negative . seventy - nine cases ( 34.2% ) had hysterectomy due to abnormal uterine bleeding ( aub ) . aub was the only reason for hysterectomy in 74 of those who had hysterectomy due to aub ( table 2 ) . among the patients that we studied , 117 had not experienced surgery , of which 37 ( 31.62% ) were pathologically positive and 80 ( 62.3% ) were pathologically negative in terms of adenomyosis . eighteen cases ( 9.4% ) had a history of previous c / s , of which 12 cases ( 66.66% ) were pathologically positive and 6 cases ( 33.33% ) were pathologically negative in terms of adenomyosis . in addition , it was found that there was a significant relationship between a history of surgery and the positive results for adenomyosis , and cesarean surgery was the most prevalent type of surgery related to adenomyosis according to its higher statistics ( p = 0.01 ) ( table 3 ) . adenomyosis is one of the most common diseases in women , and it can be accompanied by various symptoms , such as dysmenorrhea , menometrorrhagia , dyspareunia , and chronic pelvic pain . since adenomyosis is prevalent , its complications can cause physical and mental problems in women , and it also can influence their fertility and childbearing ability . it seems that prevention is necessary , but the risk factors for adenomyosis must be identified in order to prevent it . it has been found in various studies that several factors can influence adenomyosis , including chronological age , menarche age , gravidity , parity , weight , uterine size , and previous uterine surgery ( 14 ) . the average age of the patients we studied was 50.25  9.66 , which was very close to that of other studies ( 16 , 11 ) . the prevalence of adenomyosis was found to be 37.7% in our study , which was similar to the results of several other studies ( 1 , 6 , and 7 ) . however , prevalence at this level was not found in other studies ( 2 , 4 ) . according to different studies , the prevalence of adenomyosis is variable and can result from differences in the populations that are studied , differences in the diagnostic criteria of adenomyosis , and incorrect diagnoses due to the lack of standard criteria for making such a diagnosis . in our study , there was not a significant relationship between menarche age and adenomyosis . our results were in agreement with those of vercellini in which no significant relationship between menarche age and adenomyosis was found ( 6 ) . the average number of parity in women who had adenomyosis was 6.62.64 , and it was 6.42.51 in women who did not have adenomyosis , thus , there was no a significant relationship between the number of parity and adenomyosis ( p = 0.712 ) . however , different from our results , other studies have demonstrated a significant relationship between parity and increased risk of adenomyosis ( 16 ) . the results of our study were in agreement with the results of bergholt s study , which showed that there was not a significant relationship between parity and adenomyosis ( 2 ) . in our study , there was not a significant relationship between adenomyosis and gravidity ( p = 0.712 ) , but some studies reported different results and concluded that women with adenomyosis had significantly higher gravidity than the group without adenomyosis ( 1 , 11 ) . we found a significant relationship between adenomyosis and prior uterine surgery ( p = 0.03 ) . panganamamul also reported a significant relationship between adenomyosis and prior uterine surgery ( 1 ) . our results were compatible with the results of these studies ; however , there was not a significant relationship between adenomyosis and prior uterine surgery in some studies ( 2 , 11 ) . our study did not show a significant relationship between uterine size and adenomyosis ( p = 0.8 ) , but , in some studies it was indicated that the sizes of the uterus were larger when adenomyosis was present than when it was not ( 3 , 4 , 7 ) ; our results were not in agreement with this . it seems that uterine sizes of cases with adenomyosis were smaller than those without adenomyosis . according to these studies , the lack of such a hypothetically significant relationship could be due to the fact that our study was a retrospective study , and the bimanual pelvic examinations were performed by different people . hence , prospective studies should be conducted with one person as the examiner with uterine weight included in the pathology result . in our study some studies reported that both spontaneous and induced abortions were risk factors for adenomyosis ( 1 , 2 , 6 , 11 ) . according to these studies , it could be concluded that the evidence favors the fact that , in general , abortion ( spontaneous and induced ) is a risk factor for adenomyosis . according to the results obtained in this study and their comparison with those of other studies in other parts of the world , it was found that adenomyosis is more prevalent in women of childbearing age , premenopausal women with high parity and gravidity , and women who have had prior surgeries or abortions . however , there were no results that implied that there was a relationship between adenomyosis and menarche age . the results of this study were different from those of related studies concerning the prevalence of adenomyosis . adenomyosis is a prevalent disease in women of childbearing age and can cause menometrorrhagia , iron deficiency anemia , dysmenorrhea , decrease in quality of life , and obstetrical complications , such as placenta acreta , placenta increta , atonia , and uterine rupture . therefore , it is important to be able to identify , treat , and prevent adenomyosis in order to decrease its possible complications . the data showed that adenomyosis could be reduced if unnecessary uterine surgeries were reduced . in order to decrease the number of unnecessary uterine surgeries , women should be trained to avoid unnecessary caesarian sections , and physicians should emphasize the importance of avoiding unnecessary caesarian sections . then advantages of vaginal delivery and the side effects of cesarean section should be explained to women . such training could be given through mass media , health centers , and health organizations . women should be reminded of the fact that abortion should not be induced when an unexpected pregnancy occurs ; also women should seek the advice and guidance of a physician when they intend to conceive so that cases of adenomyosis and the side effects of emergency cesarean sections can be reduced to the greatest extent possible . training should be provided for women of childbearing age to make them aware of the complications of multiple pregnancies .
background : adenomyosis is a common benign disorder in pre - menopausal women that presents with uterine enlargement , pelvic pain , heavy menstrual bleeding , and dysmenorrhea . 
 however , its risk factors have not been clearly determined . 
 the aim of this study was to determine whether prior uterine surgery is a risk factor for adenomyosis.methods:in this cross - sectional study , we reviewed the medical records of all women who had hysterectomies for benign and a non - emergency , gynecological condition during 20012011 at shariati hospital in bandar - abbas , iran . 
 the variables in the study included age , gravidity , parity , abortion , prior uterine surgery , and the size of the uterus before hysterectomy . 
 the data were analyzed by microsoft excel and spss version 16 , by conducting descriptive statistics , by the t - test , and by analysis of variance ( anova).results : of the 191 participants , 72 women ( 37.7% ) had pathologically - confirmed adenomyosis . 
 women with adenomyosis reported a history of prior uterine surgery more frequently than women without adenomyosis ( p = 0.01 ) , but age , menarche , gravidity , parity , and history of abortion were similar between the two groups ( p > 0.05).conclusion : history of prior uterine surgery is a risk factor for adenomyosis .