Scholarly article on topic 'Local endometrial scratching under ultrasound-guidance after failed intrauterine insemination and cycle outcome: A randomized controlled trial'

Local endometrial scratching under ultrasound-guidance after failed intrauterine insemination and cycle outcome: A randomized controlled trial Academic research paper on "Veterinary science"

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{"Intrauterine insemination" / "Endometrial scratch" / "Pregnancy rate"}

Abstract of research paper on Veterinary science, author of scientific article — Badeea S. Soliman, Mervat Harira

Abstract Background: Interaction between the embryo and endometrium plus endometrial receptivity is considered as two strong issues affecting the implantation outcome. Purpose: To investigate the effect of local endometrial scratching on pregnancy rate after failed previous intra uterine insemination. Study design: A prospective, randomized, control trial. Setting: At Cytogenetic and Endoscopy Unit, Zagazig University Hospital. Patients and methods: A total of 226 women either with unexplained or with mild male factor infertility were divided randomly into approximately two groups: in study group, 114 women and in control group, 112 women. For both groups, folliculometry was started at cycle day 7 additionally and at the same setting; endometrial scratching was done only for the study group. Outcome results: Biochemical and clinical pregnancy rates. Results: The biochemical and clinical pregnancy rates were significantly higher in the endometrial scratching group compared to the control group [27/106 (25.5%) vs. 15/106 (14.1%) p =0.03 and 24/106 (22.6%) vs. 12/106 (11.3%); p =0.02] respectively. Also, ongoing pregnancy rate was statistically significantly different between both groups [22/106 (20.7%) vs. 11/106 (10.4%); p =0.03]. Conclusion: Endometrial scratching is useful in increasing pregnancy rates after failed previous intra uterine insemination trials when it is performed in the mid proliferative phase.

Academic research paper on topic "Local endometrial scratching under ultrasound-guidance after failed intrauterine insemination and cycle outcome: A randomized controlled trial"

Middle East Fertility Society Journal (2016) xxx, xxx-xxx

Middle East Fertility Society Middle East Fertility Society Journal

www.mefsjournal.org www.sciencedirect.com

Middle East Fertility Society Journal

ORIGINAL ARTICLE

Local endometrial scratching under ultrasoundguidance after failed intrauterine insemination and cycle outcome: A randomized controlled trial

Badeea S. Soliman *, Mervat Harira

Department of Obstetrics and Gynecology, Faculty of Medicine, Zagazig University, Egypt Received 24 April 2016; revised 10 June 2016; accepted 20 June 2016

KEYWORDS

Intrauterine insemination; Endometrial scratch; Pregnancy rate

Abstract Background: Interaction between the embryo and endometrium plus endometrial receptivity is considered as two strong issues affecting the implantation outcome. Purpose: To investigate the effect of local endometrial scratching on pregnancy rate after failed previous intra uterine insemination. Study design: A prospective, randomized, control trial. Setting: At Cytogenetic and Endoscopy Unit, Zagazig University Hospital. Patients and methods: A total of 226 women either with unexplained or with mild male factor infertility were divided randomly into approximately two groups: in study group, 114 women and in control group, 112 women. For both groups, folliculom-etry was started at cycle day 7 additionally and at the same setting; endometrial scratching was done only for the study group. Outcome results: Biochemical and clinical pregnancy rates. Results: The biochemical and clinical pregnancy rates were significantly higher in the endometrial scratching group compared to the control group [27/106 (25.5%) vs. 15/106 (14.1%) p = 0.03 and 24/106 (22.6%) vs. 12/106 (11.3%); p = 0.02] respectively. Also, ongoing pregnancy rate was statistically significantly different between both groups [22/106 (20.7%) vs. 11/106 (10.4%); p = 0.03]. Conclusion: Endometrial scratching is useful in increasing pregnancy rates after failed previous intra uterine insemination trials when it is performed in the mid proliferative phase. © 2016 Middle East Fertility Society. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

1. Introduction

Unexplained infertility is supposed when there are no detectable particular causes of infertility on a routine

evaluation (1). Evidence demonstrating that about 75% of human pregnancies not succeed almost immediately after conception incriminates that implantation failure may be a possible cause of unexplained infertility (2). Implantation process still remains a limiting step in ART outcome. Implantation is defined as the adhesion or fixation of good blastocyst to receptive endometrium throughout a specific period which is called the window of implantation (3). During this window, there is a perfect dialog between the embryo and the endometrium.

A receptive uterus includes the endometrial cellular changes and modulated appearance of different cytokines, prostaglan-

* Corresponding author.

Peer review under responsibility of Middle East Fertility Society.

http://dx.doi.org/10.1016/j.mefs.2016.06.006

1110-5690 © 2016 Middle East Fertility Society. Production and hosting by Elsevier B.V.

This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

dins, growth and transcription factors (4). Currently, implantation failure is the most important barrier in human fertility and mostly is attributed to the failure of the uterus to gain receptivity. Uterine fibroid, hydrosalpinx, endometriosis, endometrial polyp and polycystic ovary syndrome are possible causes of repeated implantation failure (RIF) (5).

Recently to improve implantation, endometrial scratching has attracted many attentions and has rapidly become included into clinical practice. It has been revealed that mechanical manipulation of the endometrium can improve receptivity by modulating gene expression of factors needed for implantation like laminin alpha 4, integrin alpha 6, matrix metalloproteinase 1 (6) and glycodelin A (7). Acute regenerative process after endometrial scratching could slow down the disproportionate endometrial development which is often associated with ovarian stimulation cycles therefore, restoring embryonic-endometrial synchrony and helping implantation (8). Another promising mechanism by which endometrial scratching may increase uterine receptivity is through local increase production of growth factors and pro inflammatory cytokines (9,10).

Animal studies have demonstrated that scratching of the endometrium provoke the decidualization and so, enhance the endometrial receptivity (11). In human there are conflicting results in this regard; Barash et al. (12) demonstrated that performing multiple endometrial biopsies at different times of the IVF cycle is associated with higher pregnancy rate. Additionally, Zhou et al. (8) demonstrated that inducing local endometrium injury in Controlled Ovarian Stimulation (COS) cycles is associated with a higher pregnancy rate. However, Karimzade et al. (13) have shown that local endometrial injury on the day of ova pickup disturbs the receptive endometrium and has a negative effect on implantation rate in IVF cycles. A Cochrane Library systematic review was published in 2015 in which moderate-quality evidence shows that endometrial injury done between day 7 of the previous cycle and day 7 of the embryo transfer (ET) cycle is associated with an improvement in clinical pregnancy and live birth rates in women with more than two previous embryo transfers cycles (14).

The aim of the study was to assess the effect of local endometrial scratching on incidence of clinical pregnancy rate after failed one IUI trial.

2. Patients and methods

This was a prospective, randomized, control trial designed to assess the effect of endometrial scratching on improving the reproductive outcome in stimulated IUI cycles. Patients who were selected to share in this work gave their written informed consent before starting. After approval of the local ethics committee, the study was performed between March 2013 and May 2015 at the Cytogenetic and Endoscopy Unit, Zagazig University Hospital, Egypt.

2.1. Patient recruitment and treatment

This study was conducted on referred women either those with unexplained or those with mild male factor infertility and after failed previous one IUI trial. Sample size was calculated based on the primary outcome of improving pregnancy rate after endometrial scratching. Two sided significant level is 95% with a power of 80% and the ratio of study to control group was

1:1. According to 36% pregnancy rate in the study group and 18% pregnancy rate in the control group as reported by Abdelhamid (15), a minimum of 106 patients were needed in each group. As there is an expecting proportion of subjects who may be dropped out before the end of the study, 10% of subjects were added; therefore, a total of 233 patients were screened regarding eligibility for the study. They fulfilled the following inclusion criteria: female age 19-37 years with normal basal hormonal profile [FSH, LH] 3-10 mIU/ml and 1.8-8.5 mIU/ml respectively, normal uterine cavity as assessed by HSG, patents both tubes and normal semen analysis. However, mild male factor infertility was defined when there was 2 or more semen analysis with 1 or more items below the 5th centile as defined by the WHO, 2010 (16). Exclusion criteria were patients with unilateral tubal patency, a history of ovarian hyper stimulation syndrome (OHSS), diminished ovarian response, endometriosis or multiple female factor. Unexplained infertility was diagnosed when there is a confirmed tubal patency, normal semen analysis according to WHO criteria, and ovulatory cycles based on ultrasonic follicle tracking and mid-luteal progesterone levels (17).

2.2. Ovarian stimulation and scratching

Before starting 7 patients were excluded from the study because they reject to participate in the study. Thus, the remaining 226 women were subjected to complete history taking and clinical examination. To exclude residual ovarian cyst, basal transvaginal pelvic ultrasonography (TVS) is mandatory for all patients. Controlled ovarian stimulation was done by combined sequential protocol CC/hMG; Clomiphene Citrate 100 mg daily starting from day 2 of the menstrual cycle and continued for 5 days. On the day following the fifth day of CC therapy, Human Menopausal Gonadotropin (hMG) (Menogon, Ferring) was starting in the form of 75 IU/day IM injection. At the same sitting of starting the COS, patients were divided randomly by using random table (computer), software Open Epi version 3.21 into two approximately groups: in study group (scratching group) 114 women in whom ovarian stimulation, scratching, folliculometry and insemination were done while in the control (non- scratching group) 112 women were subjected to ovarian stimulation, folliculom-etry and insemination. Patients were allocated to either group by the randomization stated while allocation concealment concentrated on preventing selection and confusing biases. In the study group, endometrial scratching was planned on day 7 of the same cycle, while in the control group, classic IUI was planned without endometrial scratching.

2.3. Endometrial scratching

Scratching was done by using the embryo mucus aspiration catheter (Rocket medical) which is a small, flexible catheter that can be used to scratch the lining endometrium gently after cutting the tip of the catheter sheath obliquely.

The procedure of the endometrial scratch was performed as follows:

1. Prepare the patient in the Lithotomy position.

2. Speculum is gently inserted into the vagina to expose the cervix which is cleaned with sterile gauze.

3. The sheath is inserted into the uterus through the cervical

opening after cutting its edge obliquely.

4. Once the sheath is in place, the plugger is withdrawn.

5. The lining of the posterior and anterior wall of the uterus is

gently scratched by inserting and moving the sheath catheter up and down under guidance of vaginal ultrasound.

Prophylactic antibiotics in the form of Doxycycline and Metronidazole were given for both groups and at the same time: in the scratching one to avoid pelvic infection and in the other one to avoid study bias.

2.3.1. Folliculometry and insemination

For both groups, TVS folliculometry was started at cycle day 7 and was repeated every 2-3 days with changing the dose of hMG according to the ovarian response. Stimulation continued until the leading follicles reached a mean diameter of p 17 mm and the endometrial thickness p 8 mm with a triple-line endometrial pattern. Ovulation was triggered by hCG, 10,000 IU, IM (Choriomon, IBSA, Switzerland) administration. Single IUI was done 36 h after ovulation triggering by using fresh processed semen obtained from the husband. Sperm preparation was done by double wash swim up technique using Ham's F10 culture media and sperm preparation media. After insertion of Cusco speculum, the external os was cleaned with a sterile saline. The prepared semen was loaded into a IUI catheter, after that the catheter was passed through the cervical canal into the uterine cavity. Used IUI catheter was Sperm TRANS IUI CATHETER (Garkheda Aurangabad 431005, India). The sperm suspension was gradually released without touching the fundus. Luteal phase support was done by vaginal progesterone suppositories 400 mg (Prontogest, GMP Marcyrl) once daily started at day of IUI and continued for 2 weeks later when a pregnancy test was planned. Sonographic evidence of ovulation was confirmed by disappearance of the follicle from the ultrasound view completely or change in the ultrasound measurement of the follicle size.

In both groups, during folliculometry, insemination and the follow-up, 14 women were excluded, in the study group, 8 women were excluded as follows; (2) non responsive, (2) spontaneous ovulation, (3) excessive number of follicles, and (1) lost to follow-up. While in the control group 6 women also were excluded as follows; (2) non responsive, (1) spontaneous

ovulation, (2) excessive number of follicles and (1) lost to follow-up. After exclusion, the remaining patients were 106 for each group. The main outcome measurements were biochemical pregnancy, a clinical pregnancy, miscarriage rate and ongoing pregnancy rate. A biochemical pregnancy was defined by a finding of plasma b-hCG concentration >10mU/ml two weeks after IUI. A clinical pregnancy was defined as presence of an intrauterine gestational sac with a heartbeat 3 weeks after a positive pregnancy test. A miscarriage is the spontaneous loss of a fetus before the 20th week of pregnancy. Ongoing pregnancy rate was calculated by subtracting miscarriage from clinical pregnancy rate.

2.4. Statistically analysis

Data were checked, entered and analyzed by using SPSS (Statistical Product and Service Solutions) version 19. Data were expressed as number and percentage for qualitative variables such as causes of infertility, pregnancy and miscarriage rate. Chi-square (X2) and Fisher's exact tests were used to compare the proportions and Mean ± SD for quantitative variables for example age, BMI, semen parameters and stimulation characteristic. Comparison of quantitative variables between the both groups was done using Student's t-test. P < 0.05 was considered statistically significant (see Fig. 1).

2.5. Results

Among the 233 eligible patients with unexplained infertility and mild male factor infertility, 7 women were excluded because they reject to participate in the study. Thus, the remaining 226 women were divided into two approximately groups: in study group (scratching group) 114 women and in control (non-scratching group) 112 women. After second exclusion during study for different causes, the remaining patients for analysis were 106 women for each group (Fig. 2).

The epidemiological data were compared between the study and control groups and we found that there was no statistically significant difference as regards mean age, BMI, duration and causes of infertility, basal hormonal profile as well as pre processing semen parameters (Table 1). Regarding stimulation characteristics, total dose of hMG, days of stimulation, total follicles number, mean follicles diameters, endometrial thickness and also, post processing semen parameter were similar

Figure 1 Mucous aspiration catheter with cut in its end obliquely.

Figure 2 Flowchart of the study.

Table 1 Demographic data of women of both studied groups.

Scratching group [n = 106] Control group [n = 106] t Test P value

Age/year 26.1 ± 2.8 25.5 ± 2.4 1.67 0.09

BMI/kgm2 23.1 ± 1.9 22.8 ± 1.5 1.27 0.20

Duration of infertility/year 4.31 ± 1.4 4.6 ± 1.7 1.36 0.17

FSH level/IU 5.9 ± 0.9 6.1 ± 0.8 1.71 0.09

LH/IU 4.8 ± 0.6 4.9 ± 0.3 1.53 0.13

Cause of infertility

- Male Factor 67 (69.1%) 68 (68%) 0.02 0.88

- Unexplained 30 (30.9%) 32 (32%)

Basal sperm count (x106/mL) 23.1 ± 2.1 22.7 ± 1.7 1.52 0.13

Basal sperm motility (%) 48.0 ± 5.2 46.5 ± 6.1 1.92 0.055

in both groups (Table 2). Regarding cycle outcome, and biochemical, clinical and ongoing pregnancy rates, there were statistically significant differences between both groups. However, there was no statistically significant difference observed between the both groups as regards the miscarriage rate (Table 3).

2.6. Discussion

Despite the unbelievable advances in ART, embryo implantation remains the rate-limiting step for the success outcome. Although causes of repeated implantation failure could be multifactorial or even originate from embryonic defects, earlier

Table 2 Stimulation characteristics of both studied groups.

Stimulation characteristics Scratching group [n = 106] Control group [n = 106] P value

hMG/IU per cycles 750 ± 37.5 Days of stimulation/day 11.5 ± 0.5 Total number of follicles 2.9 ± 0.8 Mean follicles diameter (mm) 20.1 ± 0.7 Endometrial thickness/mm 11 ± 1.0 737 ± 75 11.4 ± 0.4 2.7 ± 0.7 19.9 ± 0.9 10.9 ± 0.9 1.59 1.60 1.71 1.81 0.76 0.11 0.11 0.09 0.09 0.44

Post processing semen parameter -Count/mil/ml 17.9 ± 1.5 - Motility (%) 64.13 ± 1.6 18.3 ± 1.9 62.8 ± 9.3 1.70 1.45 0.09 0.15

Table 3 Cycles outcome of both studied groups.

Scratching group [n = 106] Control group [n = 106] **RR (95% CI) P value

Biochemical pregnancy 27/106 (25.5%) Clinical pregnancy 24/106 (22.6%) Miscarriage rate 2/24 (8.3%) Ongoing pregnancy rate 22/106 (20.7%) 15/106 (14.1%) 12/106 (11.3%) 1/12 (8.3%) 11/106 (10.4%) 1.8 (1.02-3.19) 2.0 (1.06-3.79) 1.0 (0.1-9.9) 2.0 (1.02-3.9) 0.03 0.02 1.0 0.03

Total 106 (100%) 106 (100%)

**RR is relative risk. P < 0.05 is considered significant.

observations reported that infertile women who had received hysteroscopic biopsies preceding subsequent IVF cycle had a higher pregnancy rate. In human, the possible role of endome-trial injury on implantation was first highlighted by Barash et al. (12) who found that endometrial injury in the cycle prior to IVF significantly improves the outcome. While some studies performed the endometrial scratching in patients booked for IVF/ICSI, other studies focused on assessing its role in increasing the pregnancy rate in IUI cycles.

This prospective randomized controlled study was performed to evaluate the effects of local endometrial scratching on fertility outcomes which was done in the mid proliferative phase of the same cycle after one failed previous IUI trial. The observation showed that there was an increase in the biochemical, clinical and ongoing pregnancy rates in the scratching group as compared to the control group, the difference was seen and it was statistically significant (25.5% vs. 14.1%, p = 0.03): for the biochemical pregnancy rate (22.6% vs. 11.3%, p = 0.02), for the clinical pregnancy rate and (20.7% vs. 10.4%, p = 0.03) for the ongoing pregnancy. These results are in agreement with similar results obtained by Abdelhamid (15) who compared the cycles outcome after endometrial injury in the cycle preceding IUI versus injury in the intervention cycle compared to the classic IUI. He concluded that performing the endometrial injury significantly increases pregnancy rates when it is done in the proliferative phase of the IUI cycle, or the cycle preceding IUI, than pregnancy rates with IUI alone 36% vs. 38% vs. 18%, respectively. Possible explanation of these similarities between their and our results may be attributed to endometrial decasualization induced by either scratching or injury making the endometrium more receptive for implantation.

Another randomized clinical trial conducted by Parsanez-had et al. (18) included a total of 217 women with unexplained infertility. They induced local endometrial injury by pipelle endometrial sampling after COS which was performed during pre-ovulatory days then followed by a regularly timed inter-

course. They concluded that local endometrial injury increased pregnancy rate compared to the control group (17.5% vs. 6.7%, p = 0.027). Further recent study carried out by Maged et al. (19) includes 154 women with unexplained infertility prepared for IUI. They divided the included women into two groups: study group undergone endometrial scratch injury (ESI) before IUI and control group undergone IUI only. They concluded that ESI significantly improves the outcome of IUI in women with unexplained infertility.

Another similar study was carried out by Zhou et al. (8) who also investigated the effect of local endometrial injury on COS cycle and incidence of embryo implantation in IVF-ET. They found that local injury to the endometrium improved the embryo implantation, clinical pregnancy, and live birth rates. Furthermore, both a systematic review and meta-analysis were conducted by El Toukhy et al. (20) and Potdar et al. (21) and demonstrated that local endometrial injury prior to starting IVF treatment may improve the chance of embryo implantation and pregnancy rate.

Possible explanation for the effect of scratching was suggested by Gnainsky et al. (22) who found that endometrial biopsy-induced inflammatory response may facilitate the preparation of the endometrium for implantation by increasing interleukin-15 (IL-15), tumor necrosis factor TNF-a and macrophage inflammatory protein 1 B (MIP-1B) expression. However, conflicting results were described by Karimzade and colleagues (13) who demonstrated that local endometrial injury on the day of ova pickup may disrupt the receptive endometrium and had a negative effect on implantation and pregnancy rates in ART cycles. Their conflicting results may be due to the selected day of oocyte retrieval to do the scratching, so there was no adequate time for wound healing, gene expression and cytokine production that may improve chance of implantation. Another conflicting study was a Retrospective cohort analysis carried out by Dian et al. (23) to evaluate the impact of local endometrial injury on clinical outcomes in ovum donation recipients after failed implantation. They did

not find any changes. Additionally, another retrospective cohort study was carried out by Werner et al. (24) to assess the impact of single endometrial biopsy in patient after failed implantation despite transfer of a morphological normal euploid blastocyst. They do a single pass endometrial biopsy in the preceding cycle before their second embryo transfer. They found that endometrial disruption has no effect on endometrial receptivity in this group of patient. A randomized clinical trial was conducted by Zarei et al. (25) in which 144 women with either mild male factor or unexplained infertility were randomly divided into 2 groups: study group undergone endometrial biopsy 6-8 days in the cycle preceding IUI and control group received no biopsy. They concluded that performing endometrial injury in the preceding cycle is not associated with increase in pregnancy rate or decrease in abortion rate.

Endometrial scratching may have a beneficial role in implantation and chance of pregnancy. However, there are still many controversies regarding patient's selection, timing of procedure, technique and number of endometrial biopsies (6). This study focuses on scratching time and select women with failed previous one IUI trial. As regards the selected time, the scratching was performed in the mid proliferative phase of the intervention cycle to confirm having adequate time for gene expression, cytokine production and other possible positive effects on the endometrium. These was supported by a study carried out by Zhou et al. (8) which conclude that local injury of the proliferative endometrium in the stimulated cycles delayed endometrial growth through wound repair process which may inducing synchronicity between the embryo and endometrium stage. On the other hand some previous studies performed trauma to the endometrium in the luteal phase of the preceding stimulating cycle, while it was done in both follicular and luteal phases in some others (12,13).

Regarding catheter type, the embryo mucus aspiration catheter was chosen as it is small, less traumatic and flexible. Scratching was performed once in the mid proliferative phase and involved the lining of the posterior and anterior wall of the uterus under guidance of ultrasound. A different study was carried out by Narvekar et al. (26) where 100 ladies with previous failed IVF, even with the transfer of good quality embryos that were randomly allocated to the study and control groups. In the study group, endometrial sampling was done twice by pipelle: one in the follicular phase and the other in the luteal phase in the cycle preceding the embryo transfer one.

Endometrial scratching is a simple, low-cost and minimally invasive procedure that may enhance biochemical and clinical pregnancy rates. Scratching was done in the same cycle of the intervention with many possible advantages: first scratching is more useful to be done during folliculometry and in the same sitting; second, the theoretical benefit of recent inflammatory response that may increase implantation; and lastly to avoid the possibility of pregnancy when it is done in the luteal phase of the cycle prior to IUI.

While, in this study endometrial scratching was performed once only and in the same cycle of IUI, multiple biopsies were performed in the prospective study carried out by Barash et al. (12) where 134 patients after failed one or more IVF trials were recruited, and 45 of them were randomly selected for repeated endometrial biopsies in luteal phase of preceding cycle. They reported that there were better implantation and clinical

pregnancy rates (27.7% vs. 14.2% and 66.7% vs. 30.3%) respectively.

As a final point, regarding the guided technique, scratching was performed under ultrasound guidance which is a simple, easy and non-invasive tool to locate and scratch the expecting site for embryo implantation. However, in a prospective study carried out by Huang et al. (27), 30 women were included with repeated implantation failure where a single, site specific hys-teroscopic biopsy-induced injury was performed on the posterior uterine wall at midline 10-15 mm from the fundus during the proliferative phase (cycle day 4-7).

3. Conclusion

Endometrial scratching in the mid proliferative phase of the intervention cycle is useful in increasing biochemical and clinical pregnancy rates in women after failed intra uterine insemination.

3.1. Limitation of this study

A first limitation of this study was the frequent hospital visits for folliculometry by transvaginal ultrasound to determine the proper IUI timing. Second, we did not measure the different markers of the endometrium responsible for successful implantation, so that we cannot comment on its roles in implantation. Therefore, further studies are required to clarify the effects of endometrial injury on the outcome of the IUI cycles.

Conflict of interest

The authors declare that there was no actual or potential financial support for this paper.

References

(1) Marc A, Fritz Speroff L. Clinical gynecologic endocrinology and infertility. 8th ed. Lippincott Williams & Wilkins, A Wolters Kluwer Business; 2011.

(2) Macklon NS, Geraedts JP, Fauser BC. Conception to ongoing pregnancy: the 'black box' of early pregnancy loss. Hum Reprod Update 2002;8:333-43.

(3) Achache H, Tsafrir A, Prus D, Reich R, Revel A. Defective endometrial pro staglandin synthesis identified in patients with repeated implantation failure undergoing in vitro fertilization. Fertil Steril 2010;94:1271-8.

(4) Baum M, Yerushalmi GM, Maman E, Kedem A, Machtinger R, Hourvitz A, et al. Does local injury to the endometrium before IVF cycle really affect treatment outcome? results of a randomized placebo controlled trial. Gynecol Endocrinol 2012;28:933-6.

(5) Donaghay M, Lessey BA. Uterine receptivity: alterations associated with benign gynecological disease. In: Seminars in reproductive medicine, vol. 25; 2007. p. 461-75.

(6) Almog B, Shalom-Paz E, Dufort D, Tolandi T. Promoting implantation by local injury to the endometrium. Fertil Steril 2010;94:2026-9.

(7) Mirkin S, Arslan M, Churikov D, Corica A, Diaz J, Williams S, Bocca S, Oehninger S. In search of candidate genes critically expressed in the human endometrium during the window of implantation. Hum Reprod 2005;20:2104-17.

(8) Zhou L, Li R, Wang R, Huang H, Zhong K. Local injury to the endometrium in controlled ovarian hyper stimulation cycles improves implantation rates. Fertil Steril 2008;89:1166-76.

(9) Dekel N, Gnainsky Y, Granot I, Mor G. Inflammation and implantation. Am J Reprod Immunol 2010;63:17-21.

(10) Haider S, Knofler M. Human tumour necrosis factor: physiological and pathological roles in placenta and endometrium. Placenta 2009;30:111-3.

(11) Finn CA, Martin L. Endocrine control of the timing of endometrial sensitivity to a decidual stimulus. Biol Reprod 1972;7:82-6.

(12) Barash A, Dekel N, Fieldust S, Segal I, Schechtman E, Granot I. Local injury to the endometrium doubles the incidence of successful pregnancies in patients undergoing in vitro fertilization. Fertil Steril 2003;79:1317-22.

(13) Karimzade MA, Oskouian H, Ahmadi S, Oskouian L. Local injury to the endometrium on the day of oocyte retrieval has a negative impact on implantation in assisted reproductive cycles: a randomized controlled trial. Arch Gynecol Obstet 2010;281:499-503.

(14) Nastri CO, Lensen SF, Gibreel A, Raine-Fenning N, Ferriani RA, Bhattacharya S, Martins WP. Endometrial injury in women undergoing assisted reproductive techniques. Cochrane Database Syst Rev 2015;3(March). http://dx.doi.org/10.1002/14651858., CD009517.pub3 CD009517.

(15) Abdelhamid AM. The success rate of pregnancy in IUI cycles following endometrial sampling. A randomized controlled study: endometrial sampling and pregnancy rates. Arch Gynecol Obstet 2013;2013(288):673-8.

(16) World Health Organization. WHO laboratory manual for the examination of human semen and sperm-cervical mucus interaction. 5th ed. Cambridge: Cambridge University Press; 2010.

(17) The Practice Committee of the American Society for Reproductive Medicine authors. Optimal evaluation of the infertile female. Fertil Steril 2006;86:S264-7.

(18) Parsanezhad ME, Dadras N, Maharlouei N, Neghahban L, Keramati P, Amini M. Pregnancy rate after endometrial injury in couples with unexplained infertility: a randomized clinical trial. Iran J Reprod Med 2013;11:869-74.

(19) Maged AM, Al-Inany H, Salama KM, Souidan II, Abo Ragab HM, Elnassery N. Endometrial scratch injury induces higher pregnancy rate for women with unexplained infertility undergoing IUI with ovarian stimulation: a randomized controlled trial. Reprod Sci 2016;23(2):239-43.

(20) El-Toukhy T, Sunkara S, Khalaf Y. Local endometrial injury and IVF outcome: a systematic review and meta-analysis. Reprod Bio Med 2012;25:345-54 [Online].

(21) Potdar N, Gelbaya T, Nardo LG. Endometrial injury to overcome recurrent embryo implantation failure: a systematic review and meta-analysis. Reprod Bio Med 2012;25:561-71 [Online].

(22) Gnainsky Y, Granot I, Aldo PB, Barash A, Or Y, Schechtman E, et al. Local injury of the endometrium induces an inflammatory response that promotes successful implantation. Fertil Steril 2010;94:2030-6.

(23) Dain L, Ojha K, Bider D, Levron J, Zinchenko V, Walster S, et al. Effect of local endometrial injury on pregnancy outcomes in ovum donation cycles. Fertil Steril 2014;102(4):1048-54.

(24) Werner MD, Forman EJ, Hong KH, Franasiak JM, Bergh PA, Scott RT. Endometrial disruption does not improve implantation in patients who have failed the transfer of euploid blastocysts. J Assist Reprod Genet 2015;32(4):557-62.

(25) Zarei A, Alborzi S, Dadras N, Azadi G. The effects of endometrial injury on intrauterine insemination outcome: a randomized clinical trial. Iran J Reprod Med 2014;12(9):647-52.

(26) Narvekar SA, Gupta N, Shetty N, Kottur A, Srinivas M, Rao KA. Does local endometrial injury in the nontransfer cycle improve the IVF-ET outcome in the subsequent cycle in patients with previous unsuccessful IVF? A randomized controlled pilot study. J Hum Reprod Sci 2010;3(1):15-9.

(27) Huang SY, Wang CJ, Soong YK, Wang HS, Wang ML, Lin CY, Chang CL. Site-specific endometrial injury improves implantation and pregnancy in patients with repeated implantation failures. Reprod Biol Endocrinol 2011;9:140. http://dx.doi.org/10.1186/ 1477- 7827-9-140..