Association of exposure to phthalates with endometriosis and uterine leiomyomata: findings from NHANES, 1999-2004

BACKGROUND

Phthalates are ubiquitous chemicals used in consumer products. Some phthalates are reproductive toxicants in experimental animals, but human data are limited.

OBJECTIVE

We conducted a cross-sectional study of urinary phthalate metabolite concentrations in relation to self-reported history of endometriosis and uterine leiomyomata among 1,227 women 20-54 years of age from three cycles of the National Health and Nutrition Examination Survey (NHANES), 1999-2004.

METHODS

We examined four phthalate metabolites: mono(2-ethylhexyl) phthalate (MEHP), monobutyl phthalate (MBP), monoethyl phthalate (MEP), and monobenzyl phthalate (MBzP). From the last two NHANES cycles, we also examined mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) and mono(2-ethyl-5-oxohexyl) phthalate (MEOHP). We used logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs), adjusting for potential confounders.

RESULTS

Eighty-seven (7%) and 151 (12%) women reported diagnoses of endometriosis and leiomyomata, respectively. The ORs comparing the highest versus lowest three quartiles of urinary MBP were 1.36 (95% CI, 0.77-2.41) for endometriosis, 1.56 (95% CI, 0.93-2.61) for leiomyomata, and 1.71 (95% CI, 1.07-2.75) for both conditions combined. The corresponding ORs for MEHP were 0.44 (95% CI, 0.19-1.02) for endometriosis, 0.63 (95% CI, 0.35-1.12) for leiomyomata, and 0.59 (95% CI, 0.37-0.95) for both conditions combined. Findings for MEHHP and MEOHP agreed with findings for MEHP with respect to endometriosis only. We observed null associations for MEP and MBzP. Associations were similar when we excluded women diagnosed > 7 years before their NHANES evaluation.

CONCLUSION

The positive associations for MBP and inverse associations for MEHP in relation to endometriosis and leiomyomata warrant investigation in prospective studies.

Pregnancy-related fibroid reduction

We tested the hypothesis that the protective effect of parity on fibroids is due to direct pregnancy-related effects by following women from early pregnancy to postpartum period with ultrasound. Of 171 women with one initial fibroid, 36% had no identifiable fibroid at the time of postpartum ultrasound, and 79% of the remaining fibroids decreased in size.

New directions in the epidemiology of uterine fibroids

Although uterine leiomyomata (fibroids) have been the leading indication for hysterectomy in the United States for decades, the epidemiological data on fibroid prevalence and risk factors are limited. Given the hormonal dependence of fibroids, most earlier studies focused on reproductive or hormonal factors. Recent analyses have extended that focus to other areas. We present previously unpublished data on the association between reproductive tract infections and fibroids that highlight the need for more detailed studies. Our review suggests that metabolic, dietary, stress, and environmental factors may also play a role in fibroid development.

Lower urinary tract injury in women in the United States, 1979-2006

OBJECTIVE

We sought to determine age-adjusted rates (AARs) of lower urinary tract injury and incidence in selected inpatient gynecologic and obstetric procedures.

STUDY DESIGN

We utilized the National Hospital Discharge Survey, 1979-2006. AARs of nonobstetric bladder and ureteral injuries and incidence of lower urinary tract injury for various hysterectomy types and deliveries were calculated for women>18 years old.

RESULTS

Overall AARs of ureteral injury decreased from 0.06-0.03 per 1000 women (1979-2006). AARs of inpatient gynecologic procedures decreased from 24.9-11.8 per 1000 women (1979-2006). By hysterectomy type, bladder injury was highest in laparoscopic-assisted vaginal hysterectomy (VH) (13.8 per 1000) and VH (13.1 per 1000). Ureteral injury recognized during hysterectomy was most common with radical hysterectomy (7.7 per 1000) and least common with laparoscopic-assisted VH (0 per 1000).

CONCLUSION

Ureteral injuries at time of inpatient surgical procedures have decreased from 1979-2006. This corresponds with a sharp decrease in inpatient gynecologic procedures.

Association of intrauterine and early-life exposures with diagnosis of uterine leiomyomata by 35 years of age in the Sister Study

BACKGROUND

Early-life exposures to hormonally active compounds and other factors may affect later response to estrogen or progesterone and hence may influence development of uterine leiomyomata (fibroids).

OBJECTIVES

We evaluated associations of in utero and early-life exposures, including soy formula, with self-report of physician-diagnosed fibroids by 35 years of age.

METHODS

Our study included 19,972 non-Hispanic white women who were 35-59 years of age when they enrolled in the Sister Study in 20032007. We estimated risk ratios (RRs) and 95% confidence intervals (CIs) using log-binomial regression models for fibroid associations with adjustment for participant's age and education, maternal age at participant's birth, birth order, and childhood family income.

RESULTS

Greater risk of early fibroid diagnosis was associated with soy formula during infancy (RR = 1.25; 95% CI, 0.971.61), maternal prepregnancy diabetes (RR = 2.05; 95% CI, 1.163.63), low childhood socioeconomic status (RR = 1.28; 95% CI, 1.011.63), and gestational age at birth (RR = 1.64; 95% CI, 1.272.13, for being born at least 1 month early). In utero diethylstilbestrol (DES) exposure was also associated with early fibroid diagnosis (RR = 1.42; 95% CI, 1.131.80), but this association was driven by women reporting probable rather than definite exposure.

CONCLUSIONS

There are plausible biological pathways by which these early-life factors could promote fibroid pathogenesis. This is the first epidemiologic study to evaluate such exposures, with the exception of in utero DES, in relation to fibroid risk, and replication of findings in other populations is needed.

Solitary and multiple uterine leiomyomas among Caucasian women: two different disorders?

OBJECTIVE

To investigate whether polymorphism in CYP17A1 gene is associated with uterine leiomyomas (ULM) and to evaluate differences in epidemiologic and genetic factors among solitary and multiple leiomyomas.

DESIGN

Prospective case control study.

SETTING

Tertiary gynecology department.

PATIENT(S)

One hundred eighty-one women with clinically and surgically diagnosed ULM, 41 healthy control subjects, and 92 population control subjects.

INTERVENTION(S)

Completing the questionnaires, peripheral venous puncture.

MAIN OUTCOME MEASURE(S)

Polymerase chain reaction and restriction-fragment-length polymorphism analyses were performed to genotype women regarding the CYP17A1 -34 A/G (rs743572) gene polymorphisms. Epidemiologic data was collected by questionnaire and compared between women with ULM and healthy control subjects.

RESULT(S)

Women with multiple ULM had higher prevalence of positive family history, lower age at menarche, lower parity, higher percentage of smoking, younger age at first sexual intercourse, lower prevalence of CYP17A1 AA genotype and lower CYP17A1 A allele frequency than healthy control subjects. These trends were not apparent among women with solitary ULM.

CONCLUSION(S)

Carriage of CYP17A1 AA is protective for developing ULM in our population. Women with solitary ULM mostly resembled healthy control subjects, whereas women with multiple ULM differed in CYP17A1 AA genotype and external stimuli.

Gynecological malignant neoplasias diagnosed after hysterectomy performed for leiomyoma in a university hospital

PURPOSE

To analyze the findings of malignant neoplasms after hysterectomy for benign conditions.

METHODS

A retrospective study from January 1987 to December 2008 was conducted. We analyzed all simple hysterectomies with or without salpingo-oophorectomy for benign conditions (leiomyoma). Incomplete dossiers of patients or cases with uncertain clinical diagnostics were excluded. We analyzed histopathological results, age, parity, indications for hysterectomies with or without salpingo-oophorectomy, stage (if malignant) and therapy.

RESULTS

2,016 hysterectomies with or without salpingo-oophorectomy were performed. Of 2,016, 652 (32.3%) had had a previous diagnosis of malignancy and 1,364 (67.7%) had had a clinical diagnosis of benignancy (leiomyoma). From the total of 1,364, three (0.22%) cases of cancer were diagnosed after anatomopathological study of the uterine specimen, two sarcomas and one endometrial cancer. No cases of incidental ovarian or uterine cervical cancer were diagnosed.

CONCLUSIONS

Gynecological malignances in surgical specimens of patients submitted to surgery (hysterectomy and/or salpingo-oophorectomy) for benign conditions are rarely found.

The relationship between thyroid nodules and uterine fibroids

Previous studies suggested that estrogen might have an important role in thyroid nodule formation. Besides, it was recently reported that women with uterine fibroids, which estrogen has effects on, had an increased incidence of thyroid nodules. Our study was to identify the relationship between uterine fibroids and thyroid nodules and to find the factors that may have influences on the occurrence of thyroid nodules. We reviewed the records of 1144 participants who attended health check-ups from 2005 to 2008. Evaluated clinical variables included the size and number of thyroid nodules, presence of uterine fibroids, menopausal status, BMI, smoking, alcohol, medication status, serum levels of cholesterol, LH, FSH, and estradiol. A total of 925 participants were included and 163 (17.6%) subjects had thyroid nodules and uterine fibroids simultaneously. A significant association between both diseases existed (P=0.010), and closer relationship was observed in premenopausal women (n=445, P=0.001). In univariate analysis of systemic E2 level and the incidence of thyroid nodule in premenopausal women, systemic E2 levels had inverse correlation with the incidence of thyroid nodules (P=0.024, OR=0.631, CI: 0.424-0.940). In multivariate logistic regression analysis, older age and the presence of uterine fibroids were the independent factors for the presence of thyroid nodules. Our study suggested that uterine fibroids in women were definitely associated with thyroid nodules and estrogen might have a pivotal role in occurrence of both uterine fibroids and thyroid nodules.

Risk factors for surgically removed fibroids in a large cohort of teachers

OBJECTIVE

To describe reproductive and lifestyle correlates of surgically confirmed fibroids.

DESIGN

Prospective cohort study.

SETTING

The California Teachers Study, an ongoing prospective study of more than 133,000 female teachers and school administrators identified through the California State Teachers Retirement System.

PATIENT(S)

California Teachers Study cohort members, reporting no previous history of fibroids, were ascertained prospectively for surgical diagnosis of fibroids using hospital patient discharge records.

MAIN OUTCOME MEASURE(S)

Multivariable Cox proportional hazards regression methods were used to assess the association of self-reported menstrual, reproductive, and lifestyle characteristics with fibroids, using ages at the start and end of follow-up (in months) to define time on study. Hazard rate ratios, presented as relative risks (RR) with 95% confidence intervals (CI), were estimated.

RESULT(S)

The strongest risk factor we identified was African-American race/ethnicity, as compared to non-Latina white women. We observed a reduced risk of fibroids for postmenopausal women in comparison to premenopausal women, but use of hormone replacement therapies (regardless of formulation) were associated with an increased risk. Other risk factors included race, a family history of fibroids, being overweight, and drinking alcohol, Smoking and diabetes were associated with a decreased risk of fibroids.

CONCLUSION(S)

These observations provide a more detailed epidemiologic profile of women with surgically managed fibroids.

Pregnancy with fibroids and its and its obstetric complication

BACKGROUND

Pregnancy along with a fibroid is a high risk pregnancy which may lead to complication with unequal gravity. Objective of this study was to assess the prevalence and obstetric complications of fibroids during pregnancy, this cross-sectional study was carried out in the Department of Gynaecology, Unit 'C', Ayub Teaching Hospital Abbottabad.

METHOD

Data of all patients who presented with fibroid during pregnancy during two years, i.e., from Jan 2006 to Dec 2007 was recorded on a proforma and analysed using SPPS-12.

RESULTS

Thirty patients were diagnosed to have fibroids during pregnancy out of 3468 deliveries, thus prevalence was 0.865% in our hospital. The age of 50% cases was from 20 to 30 years, and 30 to 35 Year (27%). Twenty-one (70%) belonged to low socioeconomic status. Ninety percent patients reached up to term pregnancy between 37 to 40 weeks. Fibroids were found less common in patients in their first pregnancy (8, 23.66%). Twenty-one (70%) patients were delivered by caesarean section, and in 1 (3.33%) patient hysterotomy was performed. Failure to progress and foetal distress was the commonest indication for caesarean section (8, 38.09%) followed by breech presentation (4, 19.04%), cord prolapse (3, 14.28%) and fibroids in the lower segment (2, 9.52%). Anaemia was the commonest complication (20, 66.66%) followed by postpartum haemorrhage (PPH) (10, 33.33%). Breech presentation was the commonest malpresentation (4, 13.33%) associated with fibroids during pregnancy. Premature rupture of membranes and cord prolapse was seen in 3 (10%) patients each. Four (13.33%) patients underwent abdominal hysterectomy. Intra uterine growth restriction IUGR was seen in 2 patients (6.66%), 2 patients ended up with abortions, 1 patient had a spontaneous pregnancy loss and the other underwent hysterotomy due to low lying placenta and heavy bleeding per vaginum. Compound presentation, neglected transverse lie, stuck head of breech, placenta increta, retained placenta, low lying placenta, were the other complications occurring in one patient each. One patient died during anaesthesia. Neonatal outcome was encouraging as 20 (67%) babies were of average birth weight and only 4 (13.33%) babies had low APGAR score and needed NICU admission. Perinatal mortality was 37/1000 live births.

CONCLUSION

Pregnancy with fibroids leads to increase in caesarean section rate due to dysfunctional labour and malpresentation. There is also increased incidence of post partum haemorrhage along with associated complication of anaemia, anaesthesia and surgery.

Total laparoscopic hysterectomy of an uterus of 1840 grams: a case report

This case report describes a total laparoscopic hysterectomy of a large uterus of a woman who recently underwent neurosurgery for a grade IV glioblastoma. Because of a severe anaemia due to chronic vaginal haemorrhage for a fibromatosis uterus, she was not able to start a chemotherapic oncological protocol. We thus decided to perform a total hysterectomy through a laparoscopic approach in order to reduce the hospital stay and to ensure a quick recovery. We studied a surgical but also anaesthesiological strategy in order to obtain a good result with no or as few as possible complications.

Myomectomy at the Federal Medical Centre Gombe

BACKGROUND

The need to conserve the uterus, against all odds even when child bearing is complete makes conservative management of uterine fibroids quite appealing in our environment. Our objective is to document the prevalence, demographic characteristics and the outcome of patients who had myomectomy

METHODOLOGY

All cases of myomectomy performed at the Federal Medical Centre Gombe between 1st January 2002 and 31st December 2004 were retrospectively reviewed. Only cases of histologically confirmed fibromyomata were included in the study. Fourty three (43) out of the 45 retrieved cases met the criteria for inclusion in the study. The age, parity Marital status, clinical presentation, and outcome were analysed using the EPI-INFO Version 6.0 statistical package.

RESULTS

There were 51 cases of myomectomy out of 581 major gynaecological surgeries giving an incidence of myomectomy of 8.8% for the period under study. The majority of the patients, 30 (69.8%) were aged between 30 and 39 years and 40 (93.0%) were of low parity. The commonest indication for myomectomy was infertility 18, (41.9%), followed by menorrhagia 12, (27.9%). The uterine size at presentation was greater than twelve weeks gestation size in 33, (76.7%) of the cases. Wound infection 6, (14%) was the commonest morbidity followed bypyrexia 3, (7%). About 10(23.3%) were single while 33 (76.7%) were married. Forty (93%) of the fibroids were located in the body of the uterus while 3 (7%) were cervical in location. Most 28 (65.1%) of the skin incisions were Pfannenstiel while 15 (34.9%) had midline subumbilical skin incision. Only 7 (16.3%) of the patients had blood transfusion. Of the 18 patients who complained of infertility, 6 (33%) had conceived.

CONCLUSION

Two thirds of the patients in this study presented with uterine masses greater than twelve week size, suggesting some delay in presentation. Liberal pelvic examination for women at risk of uterine fibroids may lead to early detection with consequent reduction in morbidity.

[Uterine fibroids]

Uterine fibroids (leiomyoma) are the most common benign tumors in women. Better understanding of the pathophysiology, as well as recent technical advancements opened the gates for new options for women who suffer from symptomatic uterine fibroids. Treatments are categorized in four groups: surgical removal, minimally invasive or noninvasive approach causing damage to cellular viability, medical treatments to reduce volume and relieve symptoms, and complementary medicine. This review may assist in tailoring the type of treatment according to age, desire for future fertility, size and location of the fibroids.

[Operative treatment of benign ovarian tumours in adolescent patients: laparotomy or laparoscopy?]

THE AIM

The aim of the study was a retrospective analysis of operative procedures, laparoscopy or laparotomy, carried out in cases of benign adolescent ovarian tumours.

MATERIAL AND METHODS

A retrospective review of 709 patient charts with ovarian tumours, who had undergone surgical interventions at The Department of Surgical Gynaecology and Endoscopy of The Polish Mother's Memorial Hospital--Research Institute in Łódź--has been conducted. Among groups of girls treated either with laparoscopy or laparotomy, the following parameters were analysed: age of the patients, character of the tumour (based on the pathological result), size of the lesion, type of the surgical procedure, duration of the hospitalisation and postoperative complications.

RESULTS

109 girls had ovarian tumours operated--54 times laparoscopy and 55 laparotomy times were performed. An average age of patients who underwent laparoscopy was 16.2 years, in case of laparotomy: 15.3 years (p > 0.05). An average size of tumours excised in laparotomy was 82 mm (60-190 mm), whereas in laparoscopy 64 mm (30-80 mm) (p > 0.05). The most common laparotomic procedure was the ovarian cystectomy (63%) and cystovariectomy (32%), while during laparoscopy the cystectomy was performed in 92% (p > 0.05). Duration of the laparoscopy was shorter, average was 46.7 min, whereas mean time of laparotomy was 49.2 min (p > 0.05). Also duration of postoperative hospitalisation was longer in case of laparotomy, its average time was 5.4 days in comparison with laparoscopy--2.8 days (p < 0.05).

CONCLUSIONS

Laparoscopy performed in adolescents due to benign ovarian tumours seems to be a very safe way of the surgical treatment. Moreover, laparoscopy reduces duration of hospitalisation and convalescence, also giving a nice cosmetic effect.

The impact of race as a risk factor for symptom severity and age at diagnosis of uterine leiomyomata among affected sisters

OBJECTIVE

The objective of the study was to identify risk factors for uterine leiomyomata (UL) in a racially diverse population of women with a family history of UL, and to evaluate their contribution to disease severity and age at diagnosis.

STUDY DESIGN

We collected and analyzed epidemiologic data from 285 sister pairs diagnosed with UL. Risk factors for UL-related outcomes were compared among black (n = 73) and white (n = 212) sister pairs using univariate and multivariate regression models.

RESULTS

Black women reported an average age at diagnosis of 5.3 years younger (SE, 1.1; P < .001) and were more likely to report severe disease (odds ratio, 5.22; 95% confidence interval, 1.99-13.7, P < .001) than white women of similar socioeconomic status.

CONCLUSION

Self-reported race is a significant factor in the severity of UL among women with a family history of UL. Differences in disease presentation between races likely reflect underlying genetic heterogeneity. The affected sister-pair study design can address both epidemiological and genetic hypotheses about UL.

Genomic and proteomic profiling II: comparative assessment of gene expression profiles in leiomyomas, keloids, and surgically-induced scars

BACKGROUND

Leiomyoma have often been compared to keloids because of their fibrotic characteristic and higher rate of occurrence among African Americans as compared to other ethnic groups. To evaluate such a correlation at molecular level this study comparatively analyzed leiomyomas with keloids, surgical scars and peritoneal adhesions to identify genes that are either commonly and/or individually distinguish these fibrotic disorders despite differences in the nature of their development and growth.

METHODS

Microarray gene expression profiling and realtime PCR.

RESULTS

The analysis identified 3 to 12% of the genes on the arrays as differentially expressed among these tissues based on P ranking at greater than or equal to 0.005 followed by 2-fold cutoff change selection. Of these genes about 400 genes were identified as differentially expressed in leiomyomas as compared to keloids/incisional scars, and 85 genes as compared to peritoneal adhesions (greater than or equal to 0.01). Functional analysis indicated that the majority of these genes serve as regulators of cell growth (cell cycle/apoptosis), tissue turnover, transcription factors and signal transduction. Of these genes the expression of E2F1, RUNX3, EGR3, TBPIP, ECM-2, ESM1, THBS1, GAS1, ADAM17, CST6, FBLN5, and COL18A was confirmed in these tissues using quantitative realtime PCR based on low-density arrays.

CONCLUSION

the results indicated that the molecular feature of leiomyomas is comparable but may be under different tissue-specific regulatory control to those of keloids and differ at the levels rather than tissue-specific expression of selected number of genes functionally regulating cell growth and apoptosis, inflammation, angiogenesis and tissue turnover.

Regression analysis of a disease onset distribution using diagnosis data

We consider methods for estimating the effect of a covariate on a disease onset distribution when the observed data structure consists of right-censored data on diagnosis times and current status data on onset times amongst individuals who have not yet been diagnosed. Dunson and Baird (2001, Biometrics 57, 306-403) approached this problem using maximum likelihood, under the assumption that the ratio of the diagnosis and onset distributions is monotonic nondecreasing. As an alternative, we propose a two-step estimator, an extension of the approach of van der Laan, Jewell, and Petersen (1997, Biometrika 84, 539-554) in the single sample setting, which is computationally much simpler and requires no assumptions on this ratio. A simulation study is performed comparing estimates obtained from these two approaches, as well as that from a standard current status analysis that ignores diagnosis data. Results indicate that the Dunson and Baird estimator outperforms the two-step estimator when the monotonicity assumption holds, but the reverse is true when the assumption fails. The simple current status estimator loses only a small amount of precision in comparison to the two-step procedure but requires monitoring time information for all individuals. In the data that motivated this work, a study of uterine fibroids and chemical exposure to dioxin, the monotonicity assumption is seen to fail. Here, the two-step and current status estimators both show no significant association between the level of dioxin exposure and the hazard for onset of uterine fibroids; the two-step estimator of the relative hazard associated with increasing levels of exposure has the least estimated variance amongst the three estimators considered.

Management of uterine fibroids: an update of the evidence

OBJECTIVES

The RTI International-University of North Carolina at Chapel Hill Evidence-based Practice Center (RTI-UNC EPC) systematically updated evidence on the management of uterine fibroids, specifically incidence and prevalence of fibroids, treatment outcomes, comparisons of treatment, modifiers of outcomes, and costs.

DATA SOURCES

We searched MEDLINE(R), Cochrane Collaboration resources, and Embase.

REVIEW METHODS

We included studies published in English from February 2000 through August 2006. We excluded studies with low sample size (based on study design, cases series < 100 and cohorts < 40) or lack of relevance to uterine fibroids. Of 107 included studies, 3 were good quality, 56 fair, and 48 poor.

RESULTS

The cumulative incidence by age 50 is 70 percent to 80 percent; black women are more likely to get fibroids at younger ages. Appearance of new fibroids and growth of existing fibroids after treatment are poorly studied. Trials of preoperative medical management indicate that treatment reduces fibroid volume but do not provide sufficient evidence of improvement in important operative outcomes. When women are treated for reasons other than symptom relief, such as when pregnancy is desired, weak evidence supports treating submucous fibroids via hysteroscopy. No well-conducted trials in U.S. populations directly compared treatment options, including the option of expectant management, or followed women to determine whether the intervention met their treatment objectives. Common procedures such as hysterectomy and myomectomy, including choice among types of myomectomy, still cannot be meaningfully compared. Studies comparing uterine artery embolization (UAE) with other procedures reported procedure time and length of stay favoring UAE, but inconsistency of the direction of effect for complications and absence of key information on longer-term outcomes suggest that this evidence base is inadequate to comment on the relative risks and benefits of UAE versus hysterectomy or myomectomy. Costs of fibroid treatment, despite shorter average lengths of stay, are rising.

CONCLUSIONS

The dearth of high-quality evidence supporting the effectiveness of most interventions for uterine fibroids is remarkable, given how common this problem is. The current state of the literature does not permit definitive conclusions about benefit, harm, or relative costs to help guide women's choices. Significant research gaps include well-conducted trials in U.S. populations that directly compare interventions on short- and, especially, long-term outcomes, studies on therapeutics for medical management, and information on treatment decisions for women who desire a pregnancy.

[Determining the risk factors of uterine myomas by using back propagation neural network]

OBJECTIVE

To evaluate the value of a back propagation (BP) network in determining the risk factors of uterine myomas.

METHODS

Using stratified randomized sampling method, 1260 women were surveyed by questionnaire. 1:2 matched case-control study was conducted in 113 cases of uterine myomas. Neural network tools box of Software MATLAB 6.5 was used to train and simulate BP artificial network. The mean impact value (MIV) for each input variables was analyzed, and was compared with multiple logistic regression analysis and log-linear model for interaction between factors.

RESULTS

BP artificial neural analysis showed that the leading risk factors for uterine myomas were delayed menstruation, family history of uterine myomas, cervicitis, menstrual disorder, induced abortion, pelvic inflammatory, oral contraceptive medication, and elytritis, with mean impact value -0.0405, 0.0361, 0.0162, 0.0143, 0.0135, 0.0117, 0.0094, 0.0087, respectively. Both BP artificial neural and logistic regression analysis showed that the sequence of leading risk factors were similar in the whole, but there were some differences observed, induced abortion was proved to be an important cooperation variable through logline model analysis respectively.

CONCLUSION

Compared to the conventional statistics method, BP artificial neural network could deal with the interaction between covariables preferably, thus provided a powerful method to risk factor analysis.

Uterine fibroid tumors: diagnosis and treatment

The incidence of uterine fibroid tumors increases as women grow older, and they may occur in more than 30 percent of women 40 to 60 years of age. Risk factors include nulliparity, obesity, family history, black race, and hypertension. Many tumors are asymptomatic and may be diagnosed incidentally. Although a causal relationship has not been established, fibroid tumors are associated with menorrhagia, pelvic pain, pelvic or urinary obstructive symptoms, infertility, and pregnancy loss. Transvaginal ultrasonography, magnetic resonance imaging, sonohysterography, and hysteroscopy are available to evaluate the size and position of tumors. Ultrasonography should be used initially because it is the least invasive and most cost-effective investigation. Treatment options include hysterectomy, myomectomy, uterine artery embolization, myolysis, and medical therapy. Treatment must be individualized based on such considerations as the presence and severity of symptoms, the patient's desire for definitive treatment, the desire to preserve childbearing capacity, the importance of uterine preservation, infertility related to uterine cavity distortions, and previous pregnancy complications related to fibroid tumors.