***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: OBJECTIVE To explore the possibility that endometrial injury modulates the expression of specific genes that may increase uterine receptivity . DESIGN Controlled clinical study . SETTING Clinical IVF unit and academic research center . PATIENT(S ) IVF patients with 28- to 30-day menstrual cycles . INTERVENTION(S ) Endometrial biopsies from two groups of patients were collected on days 20 - 21 of their spontaneous menstrual cycle . The experimental , but not the control , group underwent biopsies on days 11 - 13 and 21 - 24 of their preceding cycle . MAIN OUTCOME MEASURE(S ) Global endometrial gene expression and specific analysis of uroplakin Ib ( UPIb ) mRNA level throughout the menstrual cycle . RESULT ( S ) Local injury modulated the expression of a wide variety of genes . One of the prominently up-regulated genes was the bladder transmembranal protein , UPIb , whose expression by the endometrium is shown here for the first time . Endometrial UPIb mRNA increases after biopsy in the same cycle wct 2with an additional elevation in the following cycle . Immunohistochemical analysis localized the UPIb protein to the gl and ular-epithelial cells . Genes encoding other membrane proteins such as adipose differentiation-related protein and mucin 1 , transmembrane , were also up-regulated . CONCLUSION ( S ) The biopsy-induced increase in the expression of UPIb and other genes encoding membrane proteins supports the possible importance of the membrane structure and stability during implantation . The specific role of UPIb in uterine receptivity should be eluci date It has been speculated that controlled ovarian hyperstimulation ( COH ) , as performed during in vitro fertilization therapy , may negatively affect embryo  implantation . The objective of this prospect i ve and r and omized study was to investigate gene expression profiles of the human endometrium during the window of implantation of gonadotropin-stimulated COH cycles compared with temporally matched natural cycles ( d 21 ) . Analysis was performed with high-density oligonucleotide microarrays . In addition , other structural and functional features of the endometrium were investigated . Results corroborated that  COH  cycles depicted advancement of pinopodes appearance , histological features , and steroid receptor down-regulation when compared with natural cycles . These changes were associated with significant , albeit small , variations in gene expression ( 18 genes/expressed sequence tags and -1.55- to + 3.40-fold changes ) . Second , there were significant changes in gene expression when comparing cycles using a GnRH agonist vs. a GnRH antagonist ( 13 genes/expressed sequence tags and + 1.42- to + 2.10-fold changes ) . This is the first attempt to eluci date gene expression profiles of the endometrium during COH cycles . The observed differences in gene expression in  COH cycles using state-of-the-art protocol s may not have a major functional impact on embryo implantation BACKGROUND In this prospect i ve r and omized blinded clinical trial , we examined gene expression profiles of the human endometrium during the early and mid-luteal phases of the natural cycle . METHODS An  endometrial biopsy  was performed on day 16 ( LH + 3 ) or on day 21 ( LH + 8) , followed by RNA extraction and microarray analysis using an Affymetrix HG-U95A microchip . Data analysis was carried out using pairwise multiple group comparison with the significance analysis of microarrays ( SAM ) software . RESULTS With a false discovery rate of 0 , the analysis revealed that 107 genes were significantly and differently expressed ( > or = 2-fold ) during the early versus the mid-luteal phase of the cycle . Forty-five of these genes have not been previously linked to endometrial receptivity . Validation of the microarray data was accomplished using semiquantitative RT-PCR . We demonstrated the presence of estrogen and progesterone response elements ( ERE and PRE ) by analysis of the 5'-flanking regions of a subset of differentially regulated genes . CONCLUSIONS Using a strict bioinformatics approach of microarray data , we demonstrated significant changes in c and i date genes during the transition of the early to the mid-luteal phase of the human endometrium that may have functional significance for the opening and maintenance of the window of implantation OBJECTIVE Our purpose was to evaluate the early luteal phase of assisted reproductive cycles utilizing controlled ovarian hyperstimulation and to compare these results with those obtained in unstimulated cycles . STUDY DESIGN We undertook a descriptive study analyzing luteal phase serum progesterone levels , endometrial histologic features , and endometrial surface ultrastructure by scanning electron microscopy of cycles utilizing controlled ovarian hyperstimulation . Study sample s were obtained from 7 oocyte donors undergoing controlled ovarian hyperstimulation for the purpose of follicle aspiration in oocyte donation .  Control ( unstimulated ) serum progesterone sample s were obtained from 19 patients undergoing in vitro fertilization in unstimulated cycles . Prospect i ve recipients of oocyte donation ( n = 20 ) undergoing mock cycles of exogenous estradiol and progesterone  acted as controls for the endometrial biopsies . RESULTS Serum progesterone levels on the day of human chorionic gonadotropin administration were twofold higher in the study group than in the unstimulated group ( 1.1 + /- 0.6 vs 0.5 + /- 0.2 ng/ml , mean + /- SD , p < 0.01 ) . On the day of follicle aspiration , progesterone levels were much higher in the study group ( 8.5 + /- 2.2 vs 0.5 + /- 0.1 ng/ml , p < 0.001 ) . Histologic dating of endometrial biopsies revealed that the study group was advanced by nearly 2 days as compared with the group having artificial cycles . Pinopods , ultrastructural markers of the implantation window , were present in only one of seven study cycles as compared with all of the four artificial cycles . CONCLUSIONS The early luteal phase of cycles undergoing controlled ovarian hyperstimulation is characterized by markedly elevated serum progesterone levels during the periovulatory period , advanced endometrial histologic features , and an absence of endometrial pinopods at the time of embryo implantation . We speculate that these high levels of progesterone in the early luteal phase cause premature endometrial luteinization and a premature appearance of the implantation window , thus providing an explanation for the observed decrease in endometrial receptivity The study was conducted to evaluate if the diagnosis and treatment of intrauterine lesions with office hysteroscopy is of value in improving the pregnancy outcome in patients with recurrent in-vitro fertilization and embryo transfer failure . Four hundred and twenty-one patients who had undergone two or more failed IVF-embryo transfer cycles were prospect ively r and omized into two groups . Group I ( n = 211 ) did not have office hysteroscopic evaluation , Group II ( n = 210 ) had office hysteroscopy . The patients who had normal hysteroscopic findings were included in Group IIa ( n = 154 ) and patients who had abnormal hysteroscopic findings were included in Group IIb ( n = 56 ) . Intrauterine lesions diagnosed were operated during the office procedure . Fifty-six ( 26 % ) patients in Group II had intrauterine pathologies and the treatment was performed at the same time . No difference existed in the mean number of oocyte retrieved , fertilization rate , number of embryos transferred or first trimester abortion rates among the patients in groups . Clinical pregnancy rates in Group I , Group IIa and Group IIb were 21.6 % , 32.5 % and 30.4 % respectively . There was a significant difference in the clinical pregnancy rates between patients in Group I and Group IIa ( 21.6 % and 32.5 % , P = 0.044 , respectively ) and Group I and Group IIb ( 21.6 % and 30.4 % , P = 0.044 , respectively ) . There was no significant difference in the clinical pregnancy rate of patients in Groups IIa and IIb . Patients with normal hysterosalpingography but recurrent IVF-embryo transfer failure should be evaluated prior to commencing IVF-embryo transfer cycle to improve the clinical pregnancy rate Objective : The aim of the study was to evaluate if the diagnosis and treatment of uterine cavity abnormalities by hysteroscopy in patients undergoing IVF programme is of any value in improving clinical pregnancy outcome . Methods : 520 patients participated in this prospect i ve r and omized study and were classified into two groups . Group I ( n = 265 ) without office hysteroscopy . Group II ( n = 255 ) had office hysteroscopy and was sub classified into Group II a and Group II b. Group II a ( n = 160 ) had normal hysteroscopic findings whereas Group II b ( n = 95 ) had abnormal office hysteroscopy findings , which were corrected at the same time . Result : There was no difference in the mean number of oocytes retrieved , fertilization rate , and number of embryos transferred among the patients in different groups . Statistically significant difference was observed in terms of clinical pregnancy rates between Group I and Group II a ( 26.2 and 44.44 % , P < 0.05 ) , and Group I and Group II b ( 26.2 and 39.55 % , P < 0.05 ) , respectively . Conclusion : Patients with recurrent IVF embryo transfer failures after normal hysterosalpingography findings should also be reevaluated using hysteroscopy prior to further commencing IVF-embryo transfer cycles in order to enhance the clinical pregnancy rates OBJECTIVE To explore the possibility that local injury to the endometrium in controlled ovarian hyperstimulation cycle improves the incidence of embryo implantation and to analyze the gene expression profile in the endometria of pregnant and nonpregnant patients in in vitro fertilization/embryo transfer ( IVF-ET ) . DESIGN Prospect i ve study . SETTING A clinical assisted reproductive center of a university hospital . PATIENT(S ) Women undergoing fresh IVF-ET cycles ( n = 121 ) , treated with a long protocol for controlled ovarian hyperstimulation , whose endometrium were diagnosed by B-ultrasound showing irregular echo . INTERVENTION(S ) Local injury to the endometrium of 60 patients in controlled ovarian hyperstimulation cycle , who were r and omly selected from a total of 121 patients . Seven endometrial biopsies sample s from day 10 were analyzed by Affymetrix U133 plus 2.0 gene chip . MAIN OUTCOME MEASURE(S ) Outcomes of IVF-ET and gene expression assayed by gene chip technology . RESULT ( S ) Transfer of the same number of embryos ( 135 in the experimental and control patients , respectively ) result ed in rates of implantation ( 33.33 % vs. 17.78 % ) , clinical pregnancy ( 48.33 % vs. 27.86 % ) , and ongoing or live births per ET ( 41.67 % vs. 22.96 % ) that were higher in the experimental group compared with controls . Statistically significant differences of the expression level of 218 genes ( 41 up-regulated and 177 down-regulated ) were detected in the endometrial biopsy sample s from clinical pregnant patients and nonpregnant patients . CONCLUSION ( S ) The results suggested local injury to the endometrium during a COH cycle improved the rates of embryo implantation , clinical pregnancy and live birth in ART . We also demonstrated a statistically significant difference in the messenger RNA ( mRNA ) expression profiles in the endometrium of pregnant and nonpregnant patients . Further studies on the genes identified herein will assist in predicting implantation competence Local injury to the endometrium prior to controlled ovarian stimulation may considerably improve implantation rates and pregnancy outcomes in intracytoplasmic sperm injection patients with high-order implantation failure ( > or = 4 IVF trials and > or = 12 transferred embryos ) OBJECTIVE Exploration of the possibility that local injury of the endometrium increases the incidence of implantation . DESIGN Prospect i ve study . SETTING Clinical IVF unit . PATIENT(S ) A group of 134 patients , defined as good responders to hormonal stimulation , who failed to conceive during one or more cycles of IVF and embryo transfer ( ET ) . INTERVENTION(S ) The IVF treatment and ET were preceded by repeated endometrial biopsies , in a r and omly selected 45 of a total of 134 patients . MAIN OUTCOME MEASURES Outcome of IVF-ET treatments . RESULT ( S ) Transfer of a similar number of embryos ( 3.4 + /- 1.0 and 3.1 + /- 0.9 in the experimental and control patients , respectively ) result ed in rates of implantation ( 27.7 % vs. 14.2 % , P = .00011 ) , clinical pregnancy ( 66.7 % vs. 30.3 % , P = .00009 ) , and live births per ET ( 48.9 % vs. 22.5 % , P = .016 ) that were more than twofold higher in the experimental group as compared to controls . CONCLUSION ( S ) These results suggest that IVF treatment that is preceded by endometrial biopsy doubles the chance for a take-home baby 
    Output:
    
However , current evidence suggests that endometrial injury before IVF among women with previous repeated IVF failure is associated with increased rates of implantation , clinical pregnancy , and live birth .
CONCLUSION ( S ) Endometrial injury may have a beneficial role in implantation and improve the pregnancy rate .