Difficult embryo transfer

Middle East Fertility Society Journal (2015) xxx, xxx–xxx

Middle East Fertility Society

Middle East Fertility Society Journal www.mefsjournal.org www.sciencedirect.com

ORIGINAL ARTICLE

Difficult embryo transfer (ET) components and cycle outcome. Which is more harmful? Mohammad E. Ghanem a, Ahmed E. Ragab b,*, Laila A. Alboghdady a, Adel S. Helal a, Mohammad H. Bedairy b, Ibrahiem A. Bahlol a, Abeer Abdelaziz c a

Mansoura Integrated Fertility Center, Mansoura, Egypt Department of Obstetrics and Gynecology, Mansoura Faculty of Medicine, Mansoura, Egypt c Dermatology and Andrology Department, Mansoura Faculty of Medicine, Mansoura, Egypt b

Received 29 September 2015; revised 10 October 2015; accepted 15 October 2015

KEYWORDS Embryo transfer; Infertility; Difficult; Cycle outcome

Abstract Objective: To compare the impact of individual elements of difficult embryo transfer (D-ET): cervical traction (Cx-Tr), blood on outer sheath (Bl-OS), blood on transfer catheter (Bl-TC) and sounding (Snd) individually and in combination on clinical pregnancy rate (CPR) and implantation rates (IR) of ICSI cycles. Methods: A retrospective cohort study included 744 ICSI cycles. Easy embryo transfer (E-ET) was diagnosed if no resistance on passing the preloaded TC and the sheath through the cervix. Difficult transfer was defined if Cx-Tr and/or Snd was needed, and Bl-OS or Bl-TC was present. Cycle outcome was compared for E-ET and D-ET as a whole and individually with subgroups using Odds Ratio and 95% CI. Results: CPR for E-ET (45.6%) and D-ET (39.8%) is not statistically significantly different. Comparing E-ET with CxTr, Bl-OS or Bl-TC, Snd showed significantly lower CPR with Bl-TC and Snd subgroups only. Although IR showed no significant difference between E-ET and over all components of D-ET it tended to be lower for Bl-TC and Snd subgroups. Conclusion: Cx-Tr and/or Bl-OS do not compromise CPR or IR. Only when Bl-TC and/or Snd the uterus at the time of ET is the CPR significantly undermined and IR tends to be impaired. Ó 2015 The Authors. Production and hosting by Elsevier B.V. on behalf of Middle East Fertility Society. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-ncnd/4.0/).

1. Introduction * Corresponding author at: Mansoura University, Faculty of Medicine, 35516 Mansoura, Egypt. Tel.: +20 1064686814, +20 502370607; fax: +20 502255473. E-mail address: [email protected] (A.E. Ragab). Peer review under responsibility of Middle East Fertility Society.

Production and hosting by Elsevier

The cycle outcome in IVF/ICSI depends on many variables: female age, stimulation protocol and number of good quality embryos transferred as well as the ease of embryo transfer (1,2). Embryo transfer is one of the most critical steps among all those involved in assisted fertilization procedures (3–5). The majority of transfers are easy but in about a quarter of the transfers some degree of difficulty is encountered. Most authors define difficult transfer as that which entails at least

http://dx.doi.org/10.1016/j.mefs.2015.10.004 1110-5690 Ó 2015 The Authors. Production and hosting by Elsevier B.V. on behalf of Middle East Fertility Society. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Please cite this article in press as: Ghanem ME et al. Difficult embryo transfer (ET) components and cycle outcome. Which is more harmful? Middle East Fertil Soc J (2015), http://dx.doi.org/10.1016/j.mefs.2015.10.004

2 one of the following: resistance to advancement of loaded embryo transfer catheter requiring cervical traction and may be sounding the cervical canal or even cervical dilation, blood on outer sheath or transfer catheter (6,7). On the other hand, transfer is considered easy when the procedure is done smoothly without need to manipulate the cervix by traction or sounding or dilatation and without blood on the sheath or transfer catheter (7). Although the definition of easy versus difficult transfers is generally agreed upon in the literature, the effect of difficult transfer according to this definition on cycle outcome is debated. While some studies reported no harmful effect of difficult transfer on cycle outcome (6,8) most of the authors reported detrimental effect on cycle outcome (3–5). The reason for this debate is that the difficulties in embryo transfer in most reports (cervical traction, blood on catheter, sounding, etc.) have been traditionally given the same importance which equates cervical traction with cervical and uterine sounding and blood staining of outer sheath with blood on embryo transfer catheter. Although attempts at grading the degree of difficult transfer into intermediate and difficult transfers have been made (2,7) the importance of individual components of difficulty (cervical traction, blood on catheters, sounding) has not been considered adequately. In this cohort study we aimed to compare the impact of individual elements of difficult ET, mainly resistance to advancement of ET catheter needing cervical traction (Cx-Tr), blood on outer sheath (Bl-OS), blood on transfer catheter (Bl-TC) and sounding (Snd) in combination and individually on clinical pregnancy rate (CPR) and implantation rates (IR) of ICSI/IVF cycles. 2. Material and methods This retrospective cohort study was carried out at the fertility care unit at Mansoura University Hospitals, Egypt, and a private infertility center, Mansoura Integrated Fertility Center, Mansoura, Egypt, during the period June 2013–May 2015. The study was authorized and approved by local Institutional Research Ethical Committee at Mansoura University Hospitals and therefore has been performed in accordance with the ethical standards laid down in the Helsinki Declaration of 1975 as revised in 1983 and its later amendments. The whole cohort enrolled was 1145 ICSI cycles from women coming for infertility treatment of different causes. A total of 744 cycles were eligible for inclusion in the study as they fulfilled the following criteria: age 6 38 years, fresh first ICSI cycle, number of transferred embryos P 2 high qualities (grades A and B). Cycle protocol: The details of our cycle protocol for ICSI have been previously published by Ghanem et al. (9) and (10). In long agonist protocol, patients received mid-luteal down-regulation using daily SC 0.1 mg injection of the GnRH agonist (GnRha), Triptorelin (Decapeptyl, Ferring) until complete pituitary suppression was achieved as indicated by serum E2 < 50 pg/ml and endometrium thickness 14 mm. Ovum pickup was scheduled 34–36 h after hCG ovulation trigger. Throughout our study, we selected the best quality embryos [grades A and B only] according to Hill et al. (11) morphologic classification. Surplus good quality embryos were cryopreserved. Transfer was performed on day 3 or 5 (cleavage or blastocyst transfer) according to the number and quality of embryos obtained by fertilization. We routinely employed semirigid catheters. In our program, different experienced operators undertook the clinical management including embryo transfer. The technique of ET used was the tactile method and the same type of catheter (Labottect Gmbh, Labor-TechnicGo¨ttingen, Germany) for all patients. We used the ordinary vaginal Cusco speculum of appropriate size to the vagina and adjusted to expose the vaginal cervix. After cleaning the vagina and vaginal cervix with saline, the cervical mucus was aspirated and the cervical os flushed by a jet of culture media. The preloaded embryo transfer catheter within its sheath was then advanced through the cervical canal and the embryo deposited in the upper uterine cavity 1–2 cm below the fundus as measured during mock transfer done before ovarian stimulation without analgesia or anesthesia and with empty bladder in the lithotomy position. The embryo transfer catheter was then rechecked by the embryologist to exclude embryo retention. If resistance is encountered to the passage of the preloaded embryo catheter within its sheath, the catheter and sheath are withdrawn and handled to the embryologist. The gynecologist then pulls on the anterior lip of the cervix using a cervical tenaculum and repeats the procedure of passing the embryo catheter within its sheath. If resistance still persists, uterine sound is used to probe the cervical canal and pass through the internal os of the cervix. Re-transfer of the retained embryos was not considered difficult transfer so long as it does not fulfill the criteria of difficult embryo transfer. Included cases are all that where embryo transfer was successfully done in fresh cycle using any of the above methods. Cases needing cervical dilatation were not included nor cases in which all embryos were frozen and fresh transfer was canceled. Embryo transfer was considered easy if no resistance was encountered during passing the preloaded transfer catheter within its outer sheath through the cervical canal into uterine cavity without cervical traction (Cx-Tr), and without blood on outer sheath (Bl-OS) or embryo transfer catheter (Bl-TC) and without cervico-uterine sounding (Snd). On the other hand, it was considered difficult ET if Cx-Tr was needed or Bl-OS and Bl-TC were present or sounding the cervix was done. The difficult transfer cases were dealt stepwise. If

Please cite this article in press as: Ghanem ME et al. Difficult embryo transfer (ET) components and cycle outcome. Which is more harmful? Middle East Fertil Soc J (2015), http://dx.doi.org/10.1016/j.mefs.2015.10.004

Difficult embryo transfer (ET) components and cycle outcome resistance was encountered to passing the catheter within its outer sheath, and cervical traction was done. If this fails to pass the catheter, cervical sounding was done. Cases requiring cervical traction only were grouped in Cx-Tr group, and those requiring cervical sounding which was done under cervical traction were grouped in sounding group only. Cases with blood staining of outer sheath or embryo transfer catheter were included in the corresponding group. Cases with combined difficulties other than sounding and cervical traction were excluded from analysis to avoid summation of effects. If blood staining of the catheter tip or blood on outer sheath occurred with sounding, the case was excluded. Because few cases had multiple difficulties, we did not make separate group for multiple difficulties. Cycle outcome (CPR, IR) was compared for cycles with easy ET and those with difficult ET as a whole and individually with subgroups of Cx-Tr, Bl-OS, Bl-TC and use of sounding. 2.1. Statistical analysis Statistical analysis was performed by using SPSS for windows version 17.0 (SPSS, Chicago, IL). Continuous data were expressed as mean ± standard deviation (SD). Data were checked for normality and equality of distribution prior to any analysis being performed. Skewed continuous variables were logarithmically transformed to accomplish a normal distribution. For variables that would not reach a normal distribution by logarithmic transformation, nonparametric tests would be used via x2 test and odds ratio with 95% confidence interval (OR, 95% CI) for comparing proportions. Pvalues < 0.05 were considered to be of statistical significance. The outcome measures were CPR and IR and all comparisons were expressed as OR (95% CI). Sample size the sample size was estimated by statistic program Epinfo 7. Assuming difference in CPR of 10 between

Table 1

3 easy and difficult transfers and a ratio of easy to difficult transfers of 3:1 at a = 0.05, b = 0.80 we need a total sample of at least 684 transfers (513 easy and 171 difficult arms). 3. Results This retrospective cohort comprised a total of 744 women who were treated for infertility and subjected for IVF/ICSI as a final step. Patients’ demographic data were presented in Table 1. There were no significant differences between the two groups, easy and difficult ET as regards the baseline or cycle characteristics. Comparing easy versus difficult ET groups, the mean age (SD) was (28.5 ± 4. vs. 28.6 ± 4.5, p = 0.88), BMI (SD) (32.6 ± 6.3 vs. 31.8 ± 5.6, p = 0.08), basal FSH (SD) (6.2 ± 2.9, 5.8 ± 2.3, p = 0.24). Primary infertility was encountered in the majority of cases (71.2%) of the whole cohort. The main indication for infertility treatment was male causes in both groups being encountered in 41.6% (n 226) of easy ET vs. 42.7% (n 86) of difficult ET group with the use of long acting agonist and antagonist protocols in comparable proportions of both groups. The mean estradiol level on day 8 showed no significant difference (1267.12 ± 1125.6 in E-ET vs. 1288 ± 951.8 in D-ET, P = 0.84). Also the mean number of total egg retrieved or embryos transferred showed no significant differences in both groups (11.92 ± 6.55 vs. 11.99 ± 7.07, p = 0.89 and 2.8 ± 0.63 vs. 2.8 ± 0.59, p = 0.82 respectively). In Table 2, CPR for E-ET was found comparable with the overall CPR of D-ET (45.6% vs. 39.8%, OR 1.23, 95% CI: 0.9–1.8; P > 0.05). Comparison of E-ET with individual components of difficult ET (Cx-Tr, Bl-OS or Bl-TC, Snd) showed significantly lower CPR with Bl-TC and Snd transfer subgroups only (OR 2.6, 95% CI: 1.3–5.2 and 2.7, 95% CI: 1.2–6.1 respectively, p values 0.05

2 – All Difficult-ET- (201) 3 – Cx-Tr (83)

78 42

39.8 50.6

4 – Bl-OS (39)

17

43.6

5 – Bl-TC (45)

11

24.4

6 – Snd (34)

8

23.5

– 1 vs. 2 1.23 (0.9 to 1.8) – 1 vs. 3 0.8 (0.5–1.3) 1 vs. 4 1.1 (0.5–2.1) 1 vs. 5 2.6 (1.3–5.2) 1 vs. 6 2.7 (1.2–6.1)

*

– p > 0.05 P > 0.05 P < 0.05* P < 0.05*

p value is significant.

Table 3

Implantation rates in different groups of ET.

Groups (n)

IR (sacs/Et) (%)

Total cycles (744) 1 – Easy-E T (543)

13.9 (292/2093) 14.7 (236/1604)

2 – Difficult-ET(201) 3 – Cx-Tr (83)

11.4 (56/489) 11.7 (21/178)

4 – Bl-OS (39)

17.2 (16/94)

5 – Bl-TC (45)

9.02 (12/133)

6 – Snd (34)

8.3 (7/84)

OR (95% CI) 1 vs. 2 1.3 (0.9–1.8) – 1 vs. 3 1.3 (0.8–2.1) 1 vs. 4 0.8 (0.5–1.5) 1 vs. 5 0.9 (0.9–3.2) 1 vs. 6 1.9 (0.8–4.2)

p value – p > 0.05 – p > 0.05 p > 0.05 p > 0.05 p > 0.05

showed no significant differences compared with E-ET (45.6%) (OR 0.8, 95% CI: 0.5–1.3 and 1.1, 95% CI: 0.5–2.1, p values =>0.05). Although IR (Table 3), showed no statistically significant difference between E-ET and over all D-ET, the Bl-TC and Snd subgroups tended to have lower IR that did not reach the level of statistical significance (OR, 0.9 95% CI: 0.9–3.2 and 1.9, 95% CI: 0.8–4.2, p values >0.05) due to small number of transfers in these 2 subgroups (type II statistical error). 4. Discussion In this retrospective cohort study, we found that not all components of difficult ET are detrimental to cycle outcome in terms of clinical pregnancy and implantation rates. Whereas cervical traction (Cx-Tr) to overcome resistance and blood staining of the outer guide sheath (Bl-OS) did not affect outcome, blood on transfer catheter (Bl-Tc) and use of sound (Snd) to probe cervico-uterine canal undermined the outcome. The topic of difficult embryo transfer (ET) is plagued with debate which is caused by variation in the definition of ‘‘difficult embryo transfers”. This definition again is subjective and the published studies dealing with the topic varied in sample size, type of patients, and type of transfer: fresh or frozen ET, etc. Attesting to this variation in the definition of ‘‘difficult

embryo transfers” is the great variation in the proportion of difficult ETs in the published studies ranging from as low as 7.7% (2) and 13.1% (6) to as high as 41% (7). In our study, difficult ET was present in 201 out of 744 (27%) as presented in the tables in the results’ section of which cervical traction and blood on outer sheath combined together accounted for 60.6% of all difficult ET cases (122/201). Owing to the multitude of confounders affecting the cycle outcome in IVF/ICSI cycles (12) we selected our cohort to include only first fresh cycles excluding frozen ET, female patient below 39 years and cases which were transferred with P2 good quality embryos grades A and B according to Hill et al.’s criteria (11) using only one method of ET (blind tactile) and one type of catheter (Labotect ET catheter). Also, all ETs are performed by the same group of senior clinicians with comparable clinical experience to avoid inter-operator differences in experience (13). Although the value of prior mock embryo transfers (14) has been recently challenged (15,16) we employed it routinely before ovarian stimulation in the treatment cycle. Few studies (6,8) reported no detrimental effects of difficult embryo transfer (D-ET) compared with easy transfer (E-ET). Tur-kaspa et al. (6) prospectively compared unelected cohort of 854 consecutive embryo transfer procedures and compared outcome for easy versus difficult transfers requiring cervical traction, cervical dilatation or multiple attempts of transfer due to retained embryos. Pregnancy rates for the different categories of embryo transfer (easy, cervical traction, cervical dilation, repeated attempts) were 23.3%, 23.6%, 23.8% and 29.6% respectively with no statistically significant differences between the easy and subtypes of difficult transfer. The reason for the absence of differences in the outcome of this study might be explained by the small proportion of difficult ET (less than 15% of all cohort vs. 27% in our study), failure to control for the other confounders which affect cycle outcome in ICSI as female age, embryo quality and number and the indications for ICSI, etc. In the same way Burke et al. (8) performed a logistic regression for predictors of successful outcome in 205 transfers by a single provider. They reported that one variable was found to significantly affect the outcome; the number of high-grade embryos placed. The presence of a previous failed embryo transfer tended to lower the success rate for future attempts; however, this result did not reach statistical significance. The catheter type and the transfer difficulty did not


Difficult embryo transfer (ET) components and cycle outcome affect outcome. Apparently the small sample size (205 transfers) and failure to compare subgroups of difficult transfer (cervical traction, blood on transfer catheter, cervical and uterine sounding) may have muffled small true differences in outcome between different components. In both studies (6,8) no reference to blood staining of embryo transfer catheter or outer sheath was made. Most of the more recent studies documented that easy embryo transfer is associated with better cycle outcome (1– 3,5,15–18). However, there is still some debate as to what constitutes difficult embryo transfer. Whereas most studies agreed that blood on embryo transfer catheter and cervical sounding or dilatation is considered a difficult transfer and is almost associated with poorer outcome in agreement with our findings, there is controversy regarding the effect of cervical traction and the role of blood on outer sheath. Mansour and Aboulghar (1) in a review study considered cervical traction detrimental to outcome due to oxytocin release associated with cervical traction based on a non-randomized study that suggested a high frequency of uterine contractions on the day of transfer which impairs the outcome of IVF possibly by expelling embryos out of the uterine cavity (19) but this work has not been confirmed. Furthermore; Tremellen et al. (20) in a RCT found that sexual intercourse in the peri-transfer period did not affect cycle outcome despite the supposed increase in myometrial contraction resulting from increased prostaglandin and oxytocin release thus refuting the hypothesis of detrimental effect of cervical traction. Tomas et al. (7) in a multiple logistic regression analysis of cycle outcome predictors in 4807 ETs graded according the degree of difficulty in ET (easy, medium and difficult) found that cervical traction (graded as medium difficulty) had the same cycle outcome as easy ET. Because multiple regression analysis is a strong tool in controlling for confounders we feel that it is more acceptable compared with other studies comparing simply between outcomes for easy and difficult ET. Sallam et al. (15) in a cohort study of 784 consecutive cycles in 655 in vitro fertilization and ICSI patients found that cervical traction is not harmful to outcome. However, Singh et al. (17), Spitzer et al. (16) and Listijono et al. (2) in a retrospective analysis of ET including fresh and frozen and different types of catheters found that cervical traction is harmful to cycle outcome. Our findings agree with those by Tomas et al. (7) and Sallam et al. (15) where we found that mere cervical traction to straighten cervico-uterine angle and overcome resistance to advancement of embryo transfer catheter did not adversely affect cycle outcome provided that no trauma and bleeding on embryo transfer catheter occurred. We therefore recommend that cervical traction per se in absence of blood on embryo transfer catheter tip or sounding be considered variant of easy transfer. Concerning the presence of blood on outer sheath compared with blood on the tip of transfer catheter, there is less controversy. Although most references concur on the deleterious effect of blood on the transfer catheter (5,7,15,16,21,22) a recent systematic review and meta-analysis (23) concluded that low quality evidence suggests that a difficult embryo transfer but not a bloody catheter reduces the chance of achieving a clinical pregnancy. The review however did not specify whether it meant outer or inner sheath blood staining. It is the blood in or on the tip of the embryo transfer catheter not the outer sheath or guide canula which is associated with endometrial injury and impairment of cycle outcome

5 (15,17,21,24) in agreement with our findings. Only few studies did not link bloody embryo transfer catheter with poor outcome (2,24). However, these studies are either flawed or uncontrolled. Although it has been proved that in patients with cervical stenosis and a previous difficult ET, cervical dilatation during the initial visit leads to an easier subsequent ET and improves the pregnancy rate (25) sounding or dilating the cervix at the time of ET has been found in the majority of studies (2,7,17) to undermine cycle outcome in agreement with our findings. Usually this type of difficult transfer is associated with blood on embryo transfer catheter and implies endometrial injury which undermines cycle outcome. 5. Conclusion This study provided support to the suggestion that definition of difficult embryo transfer should be refined to include only bloody embryo transfer catheter and or use of sound to probe cervico-uterine canal at the time of embryo transfer. Cervical traction per see or cervical trauma staining outer sheath with blood should not be considered components of difficult transfer. Thus our study is hoped to have helped in resolving some of the debate found in this area of IVF research. Conflict of interest There is no conflict of interest to be declared. References (1) Mansour RT, Aboulghar MA. Optimizing the embryo transfer technique. Hum Reprod 2002;17(5):1149–53, ISSN 0268-1161. (2) Listijono DR1, Boylan T, Cooke S, Kilani S, Chapman MG. An analysis of the impact of embryo transfer difficulty on live birth rates, using a standardised grading system. Hum Fertil (Camb) 2013;16(3):211–4. (3) Sallam Hassan N. Embryo transfer: factors involved in optimizing the success. Curr Opin Obstet Gynecol 2005(17):289–98. (4) Neithardt AB, Segars JH, Hennessy S, James AN, Mckeeby JL. Embryo after loading: a refinement in embryo transfer technique that may increase clinical pregnancy. Fertil Steril 2005;83 (3):710–4, ISSN 0015-0282. (5) Mains L, Voorhis BJ. Optimizing the technique of embryo transfer. Fertil Steril 2010;94:785–90. (6) Tur-Kaspa I, Yuval Y, Bider D, Levron J, Shulman A, Dor J. Difficult or repeated sequential embryo transfers do not adversely affect in-vitro fertilization pregnancy rates or outcome. Hum Reprod 1998;13(9):2452–5. (7) Tomas Candido, Tikkinen Kimmo, Tuoivaara Leena, Tapanainen S Joha, Martikainen Hannu. The degree of difficulty of embryo transfer is an independent factor for predicting pregnancy. Hum Reprod 2002(17):2632–5. (8) Burke LM, Davenport AT, Russell GB, Deaton JL. Predictors of success after embryo transfer: experience from a single provider. Am J Obstet Gynecol 2000;82(5):1001–4. (9) Ghanem ME, Bakr NI, Elgayaar MA, El Mongy S, Fathy H, Abdel-Hamid AI. Comparison of the outcome of intracytoplasmic sperm injection in obstructive and non-obstructive azoospermia in the first cycle: a report of case series and meta-analysis. Int J Androl 2005;28:16–21. (10) Ghanem ME, Sadek EA, Elboghdady LA, Helal AS, Gamal A, Eldiasty A, et al. The effect of luteal phase support protocol on cycle outcome and luteal phase hormone profile in long agonist


6

(11)

(12)

(13)

(14)

(15)

(16)

(17)

(18)

M.E. Ghanem et al. protocol intracytoplasmic sperm injection cycles: a randomized clinical trial. Fertil Steril 2009;92:486–93. Hill GA, Freeman M, Bastias MC, Rogers BJ, Herbert CM, Osteen KG, et al. The influence of oocyte maturity and embryo quality on pregnancy rate in a program for in vitro fertilizationembryo transfer. Fertil Steril 1989;52(5):801–6. Van Loendersloot LL, van Wely M, Limpens J, Bossuyt PM, Repping S, van der Veen F. Predictive factors in in vitro fertilization (IVF): a systematic review and meta-analysis. Hum Reprod Update 2010;16:577–89. Angelini A, Brusco GF, Barnocchi N, El-Danasouri I, Pacchiarotti A, Selman HA. Impact of physician performing embryo transfer on pregnancy rates in an assisted reproductive program. J Assist Reprod Genet 2006;23:329–32. http://dx.doi.org/10.1007/ s10815-006-9032-6. Mansour R, Aboulghar M, Serour G. Dummy embryo transfer: a technique that minimizes the problems of embryo transfer and improves the pregnancy rate in human in vitro fertilization. Fertil Steril 1990;54(4):678–81, ISSN 0015-0282. Sallam HN, Agameya AF, Rahman AF, Ezzeldin F, Sallam AN. Impact of technical difficulties, choice of catheter, and the presence of blood on the success of embryo transfer—experience from a single provider. J Assist Reprod Genet 2003;20:135–42. Spitzer D, Haidbauer R, Corn C, Stadler J, Wirleitner B, Zech NH. Effects of embryo transfer quality on pregnancy and live birth delivery rates. J Assist Reprod Genet 2012;29:131–5. Singh Neeta, Gupta Prerna, Mittal Suneeta, Malhotra Neena. Correlation of technical difficulty during embryo transfer with rate of clinical pregnancy. J Hum Reprod Sci 2012;5(3):258–61. Agameya Abdel-Fattah, Sallam Hassan N. Does a difficult embryo transfer affect the results of IVF and ICSI? A meta-

(19)

(20)

(21)

(22)

(23)

(24)

(25)

analysis of controlled studies. Fertil Steril 2014;101(2). http://dx. doi.org/10.1016/j.fertnstert.2013.11.059 [Supplement, Page e8]. Lesny P, Killick SR, Robinson J, Raven G, Maguiness SD. Junctional zone contractions and embryo transfer: is it safe to use a tenaculum? Hum Reprod 1999;14(9):2367–70. Tremellen KP, Valbuena D, Landeras J, et al. The effect of intercourse on pregnancy rates during assisted human reproduction. Hum Reprod 2000;15(12):2653–8. Visser DS, Fourie F, Kruger HF. Multiple attempts at embryo transfer: effect on pregnancy outcome in an in vitro fertilization and embryo transfer program. J Ass Reprod Genet 1993;10: 37–43. Goudas VT, Hammitt DG, Damario MA, Session DR, Singh AP, Dumesic DA. Blood on the embryo transfer catheter is associate with decreased rates of embryo implantation and clinical pregnancy with the use of invitro fertilization-embryo transfer. Fertil Steril 1998;70(5):878–82. Phillips JA, Martins WP, Nastri CO, Raine-Fenning NJ. Difficult embryo transfers or blood on catheter and assisted reproductive outcomes: a systematic review and meta-analysis. Eur J Obstet Gynecol Reprod Biol 2013;168(2):121–8. http://dx. doi.org/10.1016/j.ejogrb.2012.12.030, Epub 2013 January 22. Marikinti K, Brinsden PR. The presence of blood in the transfer catheter negatively influences outcome at embryo transfer. Hum Reprod 2005;20(7):2030–1. Abusheikha N, Lass A, Akagbosu F, Brinsden P. How useful is cervical dilatation in patients with cervical stenosis who are participating in an in vitro fertilization-embryo transfer program? The Bourn Hall experience. Fertil Steril 1999;72(4): 610–2.
