***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: Background : Implantation is considered as the rate-limiting step in success of assisted reproduction techniques , and intrauterine insemination cycles . It might be affected by ovarian superovulation and endometrial local scratching . Objective : This study aims to investigate the effect of local endometrial injury on the outcome of IUI cycles . Material s and Methods : In this r and omized clinical trial 144 women with unexplained infertility , mild male factor , and mild endometriosis r and omly divided into two study groups through block r and omization . The patients were r and omly assigned to undergo endometrial biopsy between days 6 - 8 of the previous menstrual cycle before IUI ( n=72 , IUI cycles = 126 ) or receive no interventions ( n=72 , IUI cycles=105 ) . Results : The pregnancy rate per patient was 17 ( 23.6 % ) and 14 ( 19.4 % ) in endometrial biopsy and control groups , respectively ( p=0.686 ) . The pregnancy rate per cycle was 17/126 ( 13.5 % ) and 14/105 ( 13.3 % ) in endometrial biopsy and control groups , respectively ( p=0.389 ) . The abortion rate was comparable between the two groups ( 6.9 % vs. 9.7 % ; p=0.764 ) . The ongoing pregnancy rate was found to be comparable between the two study groups , as well ( 16.7 % vs. 9.7 % ; p=0.325 ) . Endometrial thickness ( p=0.609 ) was comparable between the groups ; however E2 was significantly lower in the endometrial biopsy group ( p<0.001 ) . Conclusion : Application of local endometrial injury in the cycle before the IUI cycles is not associated with increased pregnancy rate per patient and per cycle , decreased abortion , and increased endometrial thickness 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 Background : Unexplained infertility is still a challenging issue as to its causes , appropriate management and treatment . Evidence implicates early embryopathy or implantation failure as likely causes . Objective : This study aims to investigate the effect of local endometrial injury on pregnancy rate in selected unexplained infertile patients . Material s and Methods : This was a r and omized clinical trial conducted in Shiraz University Infertility Clinic of Ghadir Hospital . A total of 217 women with unexplained infertility aged 23 - 35 years old were r and omly divided into two study groups through block r and omization . After superovulation by clomiphene-citrate and gonadotropins and when the dominant follicles reached 18 - 20 mm , patients were r and omly assigned to undergo endometrial local injury at posterior uterine wall by piplle endometrial sampling ( n=114 ) or mock pipette biopsy ( n=103 ) during pre-ovulatory days ( when spontaneous urinary LH surge was detected ) . Then all the patients were instructed to follow a regularly timed intercourse . Results : The pregnancy rate was significantly higher in the endometrial injury group compared to the control group [ 17/114 ( 14.9 % ) vs. 6/103 ( 5.8 % ) ( OR : 2.83 95 % CI : 1.07 - 7.49 , p=0.03 ] . The abortion rate was comparable between two groups ( 17.64 % vs. 14.28 % ; p=0.701 ) . Conclusion : Local mechanical injury of the endometrium can enhance the uterine receptivity and facilitates the embryo implantation . This simple , easy , and cost effective procedure is worth considering in selective unexplained infertility patients who implantation failure is the likely causes of infertility before complex treatments . This procedure may help reduce psychological tensions and high expenses imposed through such interventions . Registration ID in I RCT : I RCT STUDY QUESTION What is the prevalence of chronic endometritis ( CE ) in women with repeated unexplained implantation failure ( RIF ) at IVF , and how does antibiotic treatment affect the reproductive outcome ? SUMMARY ANSWER Chronic endometritis , associated with infection with common bacteria or mycoplasma , is common in women complaining of RIF and antibiotic treatment significantly improves the reproductive outcome at a subsequent IVF cycle . WHAT IS KNOWN ALREADY We have reported that CE is a frequent finding in women with repeated pregnancy loss and a significantly higher rate of successful pregnancies was achieved after adequate antibiotic treatment . Moreover , CE was identified in 30.3 % of patients with repeated implantation failure at IVF and women diagnosed with CE had lower implantation rates ( 11.5 % ) after IVF cycles . In contrast , other authors reported that the clinical implication of CE should be considered minimal and that the reproductive outcome at IVF/ICSI cycles was not negatively affected by CE . STUDY DESIGN , SIZE , DURATION A retrospective study was performed from January 2009 through June 2012 on 106 women with unexplained infertility and a history of RIF . PARTICIPANTS / MATERIAL S , SETTING , METHODS All patients underwent hysteroscopy and endometrial sampling for histology and microbiological investigations . Women diagnosed with CE underwent antibiotic treatment and the effect of treatment was confirmed by hysteroscopy with biopsy . Within 6 months after treatment all women had a further IVF attempt . The IVF outcomes were compared in women without signs of CE ( Group 1 ) and persistent CE ( Group 2 ) after antibiotic treatment .  Clinical pregnancy rate ( PR ) , and live birth rate ( LBR ) were compared at post-treatment IVF attempt . MAIN RESULTS AND THE ROLE OF CHANCE Seventy ( 66.0 % ) women were diagnosed with CE at hysteroscopy . In 61 ( 57.5 % ) CE was confirmed by histology and 48 ( 45.0 % ) by cultures . Common bacteria and mycoplasma were the most prevalent agents . In 46 ( 75.4 % ) out of 61 women , with diagnosis of CE at hysteroscopy and histology , examinations were normal after appropriate antibiotic treatment control ( Group 1 ) while in 15 ( 24.6 % ) cases signs of CE were still present ( Group 2 ) . At IVF attempt after treatment , a significantly higher PR and LBR was reported in women from Group 1 compared with women from Group 2 ( 65.2 versus 33.0 % P = 0.039 ; 60.8 versus 13.3 % , P = 0.02 , respectively ) . LIMITATIONS , REASONS FOR CAUTION Possible biases related to retrospective studies and to preferential referral of patients with CE , and limited number of cases . WIDER IMPLICATION S OF THE FINDINGS A prospect i ve r and omized clinical trial is needed to confirm our findings but in women with RIF a hysteroscopic evaluation of the uterine cavity to exclude CE should be considered and appropriate antibiotic treatment should be given before su bmi tting the patient to a further IVF attempt Objective : This study aim ed to investigate the effect of endometrial injury using Pipelle catheter in the follicular phase ( cycle day 5 , 6 , or 7 ) of the stimulation cycle on pregnancy rates in patients undergoing intrauterine insemination .  Methods : This prospect i ve r and omized controlled study was carried out in the Assisted Reproductive Technology Unit of Ain Shams University Maternity Hospital , Cairo , Egypt , from July 1 , 2013 to August 31 , 2015 . Three hundred sixty women , 20 to 35 years of age , with patent fallopian tubes , mild male factor infertility , or unexplained infertility were recruited . Participants were allocated r and omly into 2 groups : experimental arm and control arm . Women in the experimental arm underwent endometrial biopsy using a Pipelle catheter on day 5 , 6 , or 7 of the stimulation cycle combined with intrauterine insemination . Women in the control group underwent  intrauterine insemination with no endometrial biopsy done . The primary outcomes were the clinical and chemical pregnancy rates . Results : Data of 344 participants were statistically analyzed . The chemical pregnancy rate was 23.66 % in the experimental arm and 10.85 % in the control arm ( P = .002 ) . The clinical pregnancy rate was 18.93 % in the experimental arm and 7.42 % in the control arm ( P = .003 ) . Conclusion : Endometrial injury using a Pipelle catheter in the stimulation cycle may improve pregnancy rates in women undergoing intrauterine insemination STUDY QUESTION Can controlled ovarian stimulation with low-dose human menopausal gonadotrophin ( hMG ) improve the clinical pregnancy rate when compared with ovarian stimulation with clomiphene citrate ( CC ) in an intrauterine insemination ( IUI ) programme for subfertile couples ? SUMMARY ANSWER Ovarian stimulation with low-dose hMG is superior to CC in IUI cycles with respect to clinical pregnancy rate . WHAT IS KNOWN ALREADY IUI after ovarian stimulation is an effective treatment for mild male subfertility , unexplained subfertility and minimal-mild endometriosis , but it is unclear which medication for ovarian stimulation is more effective . STUDY DESIGN , SIZE , DURATION A total of 330 women scheduled for IUI during 657 cycles ( September 2004-December 2011 ) were enrolled in an open-label r and omized clinical trial to ovarian stimulation with low-dose hMG subcutaneous ( n = 334 , 37.5 - 75 IU per day ) or CC per oral ( n = 323 , 50 mg/day from Day 3 - 7 ) . Assuming a difference of 10 % in ' clinical pregnancy with positive fetal heart beat ' , we needed 219 cycles per group ( alpha-error 0.05 , power 0.80 ) . PARTICIPANTS / MATERIAL S , SETTING , METHODS We studied subfertile couples with mild male subfertility , unexplained subfertility or minimal-mild endometriosis . Further inclusion criteria were failure to conceive for ≥12 months , female age ≤42 years , at least one patent Fallopian tube and a total motility count ( TMC ) ≥5.0 million spermatozoa after capacitation . The primary end-point was clinical pregnancy . Analysis was by intention to treat and controlled for the presence of multiple measures , as one couple could have more r and omizations in multiple cycles . Linear mixed models were used for continuous measures . For binary outcomes we estimated the relative risk using a Poisson model with log link and using generalized estimating equations . MAIN RESULTS AND THE ROLE OF CHANCE When compared with ovarian stimulation with CC , hMG stimulation was characterized by a higher clinical pregnancy rate  ( hMG 48/334 ( 14.4 % ) versus CC 29/323 ( 9.0 % ) , relative risk ( RR ) 1.6 ( 95 % confidence interval ( CI ) 1.1 - 2.4 ) ) , higher live birth rate  ( hMG 46/334 ( 13.8 % ) versus CC 28/323 ( 8.7 % ) , RR 1.6 ( 95 % CI 1.0 - 2.4 ) ) , low and comparable multiple live birth rate ( hMG 3/46 ( 6.5 % ) versus CC 1/28 ( 3.6 % ) , P > 0.99 ) , lower number of preovulatory follicles ( hMG 1.2 versus CC 1.5 , P < 0.001 ) , increased endometrial thickness ( hMG 8.5 mm versus CC 7.5 mm , P < 0.001 ) , and 
    Output:
    
CONCLUSION ( S ) Available data suggest that ESI performed once , preferably during the follicular phase of the same cycle of IUI with flexible aspiration catheters , may improve clinical pregnancy and ongoing pregnancy rates in IUI cycles .
Endometrial scratch injury does not appear to increase the risk of multiple pregnancy , miscarriage , or ectopic pregnancy