Can clinicians improve implantation?

1. Can clinicians improve implantation? Omur Taskin,M.D Dept. Obstet&Gynecol, Div. Reprod. Endocr. Akdeniz University School of Medicine

2. What is meant by “endometrial receptivity”??

3. Is it a transient stage of endometrial function following initiation of implantation??

4. Or a biologically autonomous condition of endometrium that can be recognized in the absence of implanting blastocyst??

5. Primed endometrium may be more receptive and associated with surface receptivity may only induced by suitable embryonic stimulus

6. Under the influence of steroid hormones, endometrium: Powerful paracrine tissue Bidirectional signals between embryo/stroma Initiating embryo/uterine crosstalk Primary of activating implanting blastocystthrough the local action of cytokines or eicosanoids so not just an adhesive surface

7. Three-stage process • Apposition • Adhesion • Invasion Involving synchronized crosstalk between a receptive endometrium and a functional blastocyst

8. Implantation involves • Complex squence of signalling events consisting Acquisition of adhesion ligands With loss of inhibitory components

9. Implantation is a complicated process that requires the orchestration of a series of events involving both the embryo and the endometrium

10. implantation rates remain around 25-35%(European IVF-Monitoring Program,2005).

11. Problems? • High rates of implantation failure • early pregnancy loss in IVF • increase the transfer of multiple embryos.

12. Then what are the important players of the feto-maternal crosstalk in appositıon and adhesion phases?

13. Endometrial morphology Histology pinopods

14. Cellular adhesion molecules Integrins Selectins Cadherins Immunoglobulins mucins

15. cytokines LIF IL-1

16. prostaglandins prostaglandins

18. Ways in which a clinician could try to improve implantation rate.

19. Embryo transfer technique cervical manipulation may result in an increase of contractions of the uterus, which has been observed to severe IVF outcome, possibly by expelling embryos from the uterine cavity Fanchin et al.,1998

20. stiff vs soft embryo transfer catheters • In a recent meta-analysis of seven randomized controlled trails (RCT) comparing stiff and soft embryo transfer catheters, significantly increased pregnancy rates were observed with the latter (odds ratio(OR) 1.34, 95% confidence intervals(CI)1,18-1,54) (Buckett,2006)

21. Traditionally, embryo transfer after IVF has been performed ‘blindly’, with the aim of placing the embryos 1 cm below the fundus of the uterus (Schoolcraft, 2001)

22. Deposition of embryos • In a prospective investigation significantly better results were obtained when the catheter tip was positioned close to the middle of the endometrial cavity (Oliveira et al.,2004) • However, another randomized study revealed significantly higher implantaion rates when embryos were deposited 1,5 or 2 cm from the fundus, compared with 1 cm (Coroleu et al.,2002) • suggesting that for every additional 1 mm that embryos are deposited away from the fundus, the odds of clinical pregnancy increased by 11% (Pope et al.,2004)

23. Role of USG • The blind nature of traditional ‘clinical touch’ embryo transfer had led to the suggestion of a role for ultrasound in improving IVF outcomes. • A meta-analysis of four RCT comparing ultrasound-guided embryo transfer versus clinical touch showed a significant higher pregnancy rate and implantation rate after ultrasound-guided transfer (1,38 , 95% CI 1,20-1,60) (Buckett,2003)

24. BV colonization • During embryo transfer, it is likely that bacteria from the cervix may be introduced into the uterine cavity. Bacterial vaginosis is characterized by an overgrowth of anaerobic organisms; the prevalence among women undergoing IVF is approximately 25% (Liversedge et al.,1999).

25. Careful evaluation of the uterus • Avoiding the initiation of uterine contractility • Removing the cervical mucus • Proper placement of the embryos • Minimizing embryo expulsion

26. Adjuvant pharmaceutical therapies

27. Aspirin

28. Randomized controlled trials investigating the use of aspirin as an empirical therapy in non-selected IVF populations.

29. Low-dose aspirin for in vitro fertilization: a systematic review and meta-analysis T.A.Gelbaya et al., human reproduction, 2007

30. Clinical pregnancy (CP) rate per embryo transfer (ET) was not found to be significantly different between patients who received low-dose aspirin and those who received placebo or no treatment (RR 1.09 95% CI 0.92-1.29). None of the other outcomes, including CP per cycle, spontaneous abortion or ectopic pregnancy per CP and LB rate per cycle or ET was found to differ significantly between the compared groups. On the basis of up-to-date evidence, low-dose aspirin has no substantial positive effect on likelihood of pregnancy and, therefore, it should not be routinely recommended for women undergoing IVF/ICSI.

31. A large body of evidence shows that APL antibodies, occasionally found in low-risk obstetric populations (Lockwood et al.,1989; Stern et al., 1998) , are commonly found in women with reproductive dysfunction such as recurrent pregnancy loss (RPL) (Cowchock et al., 1986 ;Matzner et al., 1994; Yetman and Kutteh, 1996) and idiopathic infertility (Gleicher et al., 19891994; Birdsall et al., 1996)

32. Nevertheless, there is much controversy with regard to the association between APL antibodies and IVF outcome. Unlike the studies showing benefits after the use of heparin and aspirin in women with RPL (Kutteh, 1996; Rai et al., 1997; Tulppala et al., 1997) , there is no consensus regarding its use in IVF patients.

33. Characteristics of controlled trials on low-dose aspirin and IVF outcome included in the systematic review

34. Forest plot of the effect of aspirin versus placebo or no treatment on clinical pregnancy rate per embryo transfer. Review: aspirin versus nothing in IVF. Comparison: aspirin versus placebo or no treatment. Outcome: clinical pregnancy/embryo transfer.

35. Forest plot of the effect of aspirin versus placebo or no treatment on miscarriage rate per clinical pregnancy. Review: aspirin versus nothing in IVF. Comparison: aspirin versus placebo or no treatment. Outcome: miscarriage/clinical pregnancy.

36. Forest plot of the effect of aspirin versus placebo or no treatment on cycle cancellation rate. Review: aspirin versus nothing in IVF. Comparison: aspirin versus placebo or no treatment. Outcome: no. of cycles cancelled/cycles.

37. Main results of the two RCTs comparing aspirin versus placebo in poor responders (Lok et al., 2004) or oocytes recipients (Weckstein et al., 1997)

38. Nitric oxide donors

39. Effect of vaginal sildenafil on the outcome of in vitro fertilization(IVF) after multiple IVF failures attributed to poor endometrial development Geoffrey S. et al.,fertility sterility,2002

40. Patients: A cohort of 105 infertile women aged <40 years, with normal ovarian reserve and at least two consecutive prior IVF failures attributed to inadequate endometrial development

41. Interventions: patients underwent IVF using a long GnRH-a protocol with the addition of sildenafil vaginal suppositories (25 mg, 4 times per day) for 3-10 days

43. Although subgroups of women may be identified who benefit from NO donor therapy, at present the available data demand caution in its use, which at present the available data demand caution in its use, which at present should be restricted to well-designed studies.

44. Aromatase inhibitors

45. Ascorbic acid • Ascorbic acid appears to be involved in normal folliculogenesis (Luck et al.,1995), ovulation (Igarashi,1977) and luteal formation and regression (Luck and Zhao,1993). • An imbalance of oxidative stress and antioxidant defence has been implicated in the pathogenesis of several diseases, including recurrent abortion, unexplained infertility and defective embryo development. • However, a RCT investigating the effect of 1,5 or 10 mg of ascorbic acid versus a placebo during the luteal phase in 620 women undergoing IVF showed no difference in implantation rates (Griesinger et al.,2002).

46. Prolonged progesterone

47. An important regulator of endometrium receptivity is the corpus luteum, the primary function of which is the production of progesterone. • The optimal duration of progesterone administration remains to be clarified. Many centers continue with progesterone supplementation throughout the first trimester of pregnancy. However, the rationale for this approach is unclear. Proponents point to the uterine relaxing properties of progesterone, elegantly demonstrated by a reported negative correlation between uterine contractility frequency and progesterone concentrations (Fanchin et al.,1998) • Secondly, progesterone has been shown to have potentially beneficial immunomodulatory properties. Studies in mice demonstrated that progesterone administration abrogated the abortigenic effects of stress exposure by decreasing the frequency of Th1 cytokines (Blois et al., 2004). Previous studies suggested that succesful pregnancy is more likely when Th2 rather than Th1 cytokines are predominant (Wegmann et al., 1993)

48. Although supplementation of progesterone is widely used to improve implantation rates, the application of luteal oestradiol supplementation remains controversial. • A meta-analysis of three RCT (Smitz et al., 1993; Lewin et al.,1994; Farhi et al.,2000) using a long GnRH agonist protocol, reported no difference in pregnancy rates when oestrogen was added to progesterone in the luteal phase (Pritts and Atwood,2002). • In contrast, a recent RCT of 166 women undergoing ICSI reported significantly higher pregnancy and implantation rates after oestradiol supplementation (Lukaszuk et al.,2005).

49. Glucocorticoids • Uterine receptivity is controlled by locally acting growth factors, cytokines and uterine natural killer (uNK) cells (Dey et al.,2004). It has been shown that uNK cells may have an important role in early implantation, since they accumulate around arteries supplying the implantation site (Croy et al.,2002). • A defect in the integrity of the number of uNK cells has also been implicated in implaniation failure. Ledee-Batailie et al. reported higher numbers of NK cells in endomelrial biopsies from women with implantation failure versus fertile controls (Ledee-Bataille et al.,2005). • An RCT of 206 patients, investigating the use of glucocorticoids from oocyte retrieval onwards, reported no differences in embryo implantation or pregnancy rates (Moffitt et al.,1995). These results are in line with another RCT addressing the effect of adjuvant glucocorticoids (Mottia et al.,2005).

50. Peri-implantation glucocorticoid administration for assisted reproductive technology cycles Boomsma C. et al., cochrane dtabase syst rev, 2007