Abstract
Background & objectives:
Women with endometriosis often need in vitro fertilization (IVF) to concieve. There are conflicting data on the results of IVF in patients with endometriosis. This study was undertaken to elucidate the influence of endometriosis on IVF outcome to give the best counselling for infertile patient with this problem.
Methods:
The outcome measures in 78 patients with surgically confirmed endometriosis were compared with 157 patients with tubal factor infertility, all of whom have undergone IVF. The groups were matched for age and follicle stimulating hormone (FSH) levels. Outcome measures included number of follicles, number of ocytes, peak oestradiol (E2) concentrations and mean number of ampoules of gonadotropins. Cumulative pregnancy, miscarriage and live birth rates were calculated in both the groups.
Results:
Higher cancelation rates, higher total gonadotropin requirements, lower peak E2 levels and lower oocyte yield were found in women with endometriosis and previous surgery compared with those with tubal factor infertility. However, no differences were found in fertilization, implantation, pregnancy, miscarriage, multiple births and delivery rates between the endometriosis and tubal factor infertility groups.
Interpretation & conclusions:
The present findings showed that women with endometriosis and previous surgery responded less well to gonadotropins during ovarian stimulation and hence the cost of treatment to achieve pregnancy was higher in this group compared with those with tubal factor infertility. However, the outcome of IVF treatment in patients with endometriosis was as good as in women with tubal factor infertility.
Keywords: Endometriosis, gonadotropins, infertility, in vitro fertlization, pregnancy
Endometriosis affects 2-10 per cent of women in general population and 20-50 per cent of women who are investigated for infertility1. Despite extensive studies, the exact mechanism by which endometriosis cause infertility is not clearly understood. In vitro fertilization and embryo transfer (IVF-ET) has become a common method to help women with endometriosis-associated infertility. Using IVF-ET it is possible to bypass the suspected disturbed functions which affect the natural cycles by endometriosis such as altered folliculogenesis, ovulatory disfunction, oocyte maturation, cleavage of embryo and implantation2,3.
The results of different studies on whether the outcome of IVF-ET is as good in women with endometriosis as in patients with other causes of infertility, are controversal. Some investigators have reported poor IVF outcome in women with endometriosis related infertility4,5, while others reported high sucess rates comparable to those in women with tubal factor infertility6,7. The present study was undertaken to analyze the results of IVF-ET and to elucidate the influence of endometriosis on IVF outcome in women with endometrosis who have undergone laparoscopy compared with those women with tubal factor infertility to give the best counselling for infertile patients with endometriosis.
Material & Methods
A total of 235 first-attempt IVF cycles performed in two IVF units outcome (IVF unit in clinic for Gynaecology and Obstetrics Clinical Center of Nis, Serbia and IVF unit in clinic for gynecology and obstetrics, Clinical Center of Vojvodina Novisad, Serbia) were prospectively analyzed in three years period (December 2009-December 2012). The study protocol was approved by the Ethics Commitee of both IVF units and the study was conducted after obtaining informed written consent of all patients. A total of 78 women were enrolled consecutively and diagnosed with endometriosis. All patients with endometriosis have previosly undergone laparoscopy; 40 patients were diagnosed with minimal and mild endometriosis (American Society for Reproductive Medicine stage I/II) and 38 with moderate and severe endometriosis (American Society for Reproductive Medicine stage III/IV)8. Of these 78 women, 68 had undergone only one and 12 more than one surgical procedures. In all patients with ovarian endometriosis the “stripping” technique was used to excide endometriomas and the diagnosis was histologically confirmed. All patients with endometriosis were treated with 3-6 cycles of gonadotropin releasing hormone (GnRH) analogues after laparoscopy and prior to IVF. The control group consisted of 157 women who underwent IVF treatment during the same time period, with laparoscopically diagnosed tubal factor infertility and without any evidence of endometriosis.
Sample size estimation was performed to determine the number of women per group sufficient to detect a true odds ratio (OR) of 2.5. With a power of 80 per cent, type 1 error of 5 per cent, and 0.20 probability of exposure in controls, it was calculated that at least 69 subjects (ORs = 2.5) were required in the study group and at least 138 subject in the control group.
Depending on the women's age, the antral folicle count and the basal (day 3) follicle stimulating hormone (FSH), the long GnRH-agonist downregulation protocol (Dipherelin 0,1 mg, Ipsen Pharma Biotech, France), the short GnRH-agonist or GnRH antagonist protocol (Cetrotide, Serono Pharma, Switzerland) were used. Ovulation stimulations were conducted with daily subcutaneous injections of individual starting doses of rFSH (Folitropin alpha- Gonal F, Serono Pharma, Switzerland or Folitropin beta- Puregon, Organon, or human menopausal gonadotropin (hMG) (Menopur, Feriing, Germany) at appropriate doses (50-450IU). Ovarian response to gonadotropins was monitored by transvaginal ultrasound and serum estradiol (E2) measurement (Abcam, USA) every second day from day 7. Ovulation was triggered by injecting 10000IU hCG when the leading follicle reached 18 mm with appropriate serum E2 levels. Thirty six hours after administration of human chorionic gonadotropin (hCG), transvaginal ultrasound-guided oocyte aspiration was performed under local anaesthesia. After cultivation, embryo transfer was performed 3 to 5 days after oocytes aspiration. All patients received luteal phase support for two weeks. Clinical pregnancy was defined as the visualization of gestational sac at ultrasound examination and biochemical pregnancy was defined as detection of β-hCG levels in serum but no signs of pregnancy by ultrasound.
Data are expressed as the mean ± standard deviation or as percentages. Statistical comparisons among groups were performed using the Fisher exact test, χ2 test, Wilcoxon's test or Student's t test as appropriate.
Results
Patients characteristics and ovarian stimulation parameters are shown in Table I. Women with endometriosis required more ampoules of gonadotropins and attained lower serum E2 levels on day 7. The number of follicles ≥16mm on the day of hCG administration was significally (P<0.05) lower compared to tubal factor patients group. Primary infertility and OHSS rates were significally (P<0.05) lower in women in the endometriosis group.
Table I.
Patient characteristics and controlled ovarian hyperstimulation parameters
IVF laboratory parameters are presented in Table II. Cycle cancellation rate was significally (P<0.01) higher for women in the endometriosis group compared with contro group. Also, the total number of oocytes retrieved and total numer of embryos were significally lower in these endometriosis group. No significant differences were found between the groups with regard to the fertilization rate or percentage of blastocysts. A similar number of embryos were transfered in both the groups.
Table II.
IVF laboratory parameters in women with endometriosis compared with women with tubal factor infertility
Implantation rates, clinical pregnancy rates and live birth rates were comparable between the two groups. No significant differences were found in the miscarriage rate and multifoetal pregnancy rate between the endometriosis and tubal factors infertility groups of patients (Table III).
Table III.
IVF outcomes (%) in women with endometriosis and tubal factor infertility
Discussion
There is a lack of consensus among studies as to whether ovarian response is adequate or suboptimal in patients with ovarian endometriosis. Some studies have reported impaired ovarian responsiveness to ovarian stimulation in patients with endometriosis8,9 and others reported lack of adverse effect10,11. We found a detrimental relationship between endometriosis and ovarian response during controlled ovarian hyperstimulation in IVF. Despite having similar FSH levels on day 3 in women with endometriosis with previous ovarian surgery compared with those with tubal factor infertility, women with endometriosis required significantly higher dosages of gonadotropins, achieved lower peak E2 levels and yielded fewer oocytes. Women with endometriosis had also higher cycle cancellation rates. These findings suggested that the ovarian responsiveness was damaged after the presence and excision of ovarian endometriomas. There are currently insufficient data to clarify whether this endometrioma-related damage to ovarian responsiveness precedes or follows surgery. Elucidation of this point is important as it would impact on the decision of whether to operate on women with endometriosis who are selected for IVF. At present, there appears to be evidence supporting both an endometrioma-related injury12,13 and surgery-mediated damage14,15.
There is also a lack of consensus in the reported literature on IVF success in patients with endometriosis. In a meta-analysis of 22 studies, Barnhart et al16 reported that the odds of pregnancy in patients with endometriosis undergoing IVF/ET was 50 per cent compared to women with tubal factor infertility. The findings of Witsenburg et al17 are in contrast to the previous one. Based on the Centers for Disease Control (CDC) data, similar pregnancy and live birth rates have been reported when comparing couples with diagnosis of tubal factor infertility, ovulatory disfunction, endometriosis, male factor and unexplained infertility17. We found no adverse outcome of endometriosis (after ovarian surgery) on fertilization and implantation rate in the present study. Although fewer embryos were available for tranfer, as a consequence of fewer yielded oocytes, the same number of embryos were transfered. Moreover, in contrast to other groups of women with diminshed ovarian reserve, implantation rate, pregnancy rates and misccariage rates were similar in the two groups. There were no significant differences in the live birth rates between women with endometriosis and those with tubal factor infertility.
These contrasting results can be explain by several hypotheses. First of all, it seems that reduced ovarian responsiveness is related to quantitative rather than quantitative damage after surgery for ovarian endometriosis. Secondly, ovarian endometriomas are monolateral in 72-81 per cent of cases18. Bilateral disease was present in 13 per cent of patients in our study. The contralateral intact ovary may adequately compensate for the reduced function of the affected one. Third, all patients in our study were treated with GnRH agonists for 3 to 6 month after the surgery and prior to IVF. Data from Cohrane collaboration reports that long-term administration of GnRH agonists prior to IVF in women with endometriosis increases the odds of clinical pregnancies by at least four-fold and live-birth rate by tree-fold19. The improvement in the live birth and clinical pregnancy rate in patients receiving GnRH analogues may be due to an improvement in the quality of oocytes (and hence the embryos) or due to an improvement in the uterine receptivity leading to better implantation and diminshed loss of very early pregnancies. Many studies have tried to give an answer by using oocyte donation (OD) programme20,21,22. The overall conclusion, using the fact that women receiving oocytes from donors with endometriosis had reduced implantation rate and on the other hand, the women patients with and without endometriosis receiving oocyte from non endometriotic donor had the same implanatation rate, was that endometrial priming protocol with GnRH agonists used in OD cycles reestablished an adequate uterine cavity environment. One of the prosposed mechanisms is that GnRH agonists restore the normal apoptotic rate (usually low in eutopic and ectopic endometrial cells from women with endometriosis)23. There is a need for further research into the exact mechanism by which GnRH agonist improves pregnancy rates.
Inspite the fact that women with endometriosis require higher doses of gonadotropins for ovarian stimulation and hence the cost of treatment to achieve pregnancy is higher, the outcome of IVF treatment in women with endometriosis is as good as in women with tubal factor infertility.
References
- 1.Batt RE. USA: University of Buffalo, State University of New York; 2008. Emergence of endometriosis in North America: a study in the history of ideas, Ph.D. dissertation; pp. 109–13. [Google Scholar]
- 2.Milingos S, Protopapas A, Kallipolitis G, Drakakis P, Makrigiannakis A, Liapi A, et al. Laparoscopic evaluation of infertile patients with chronic pelvic pain. Reprod Biomed Online. 2006;12:347–53. doi: 10.1016/s1472-6483(10)61008-5. [DOI] [PubMed] [Google Scholar]
- 3.Milingos S, Mavrommatis C, Elsheikh A, Kallipolitis G, Loutradis D, Diakomanolis E, et al. Fecundity of infertile women with minimal or mild endometriosis. A clinical study. Arch Gynecol Obstet. 2002;267:37–40. doi: 10.1007/s00404-001-0262-7. [DOI] [PubMed] [Google Scholar]
- 4.Bulletti C, Coccia ME, Battistoni S, Borini A. Endometriosis and infertility. J Assist Reprod Genet. 2010;27:441–7. doi: 10.1007/s10815-010-9436-1. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Geber S, Ferreira DP, Spyer Prates LF, Sales L, Sampaio M. Effects of previous ovarian surgery for endometriosis on the outcome of assisted reproduction treatment. Reprod Biomed Online. 2002;5:162–6. doi: 10.1016/s1472-6483(10)61619-7. [DOI] [PubMed] [Google Scholar]
- 6.Suganuma N, Wakahara Y, Ishida D, Asano M, Kitagawa T, Katsumata Y, et al. Pretreatment for ovarian endometrial cyst before in vitro fertilization. Gynecol Obstet Invest. 2002;54(Suppl 1):36–40. doi: 10.1159/000066293. [DOI] [PubMed] [Google Scholar]
- 7.Tinkanen H, Kujansuu E. In vitro fertilization in patients with ovarian endometriomas. Acta Obstet Gynecol Scand. 2000;79:119–22. doi: 10.1034/j.1600-0412.2000.079002119.x. [DOI] [PubMed] [Google Scholar]
- 8.Al-Azemi M, Bernal AL, Steele J, Gramsbergen I, Barlow D, Kennedy S. Ovarian response to repeated controlled stimulation in in-vitro fertilization cycles in patients with ovarian endometriosis. Hum Reprod. 2000;15:72–5. doi: 10.1093/humrep/15.1.72. [DOI] [PubMed] [Google Scholar]
- 9.Ho HY, Lee RK, Hwu YM, Lin MH, Su JT, Tsai YC. Poor response of ovaries with endometrioma previously treated with cystectomy to controlled ovarian hyperstimulation. J Assist Reprod Genet. 2002;19:507–11. doi: 10.1023/A:1020970417778. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 10.Marconi G, Vilela M, Quintana R, Suelde G. Laparoscopic ovarian cystectomy of endometriomas does not affect the ovarian response to gonadotropin stimulation. Fertil Steril. 2002;78:876–8. doi: 10.1016/s0015-0282(02)03326-5. [DOI] [PubMed] [Google Scholar]
- 11.Canis M, Pouly JL, Tamburro S, Mage G, Wattiez A, Bruhat MA. Ovarian response during IVF-embryo transfer cycles after laparoscopic ovarian cystectomy for endometriotic cysts of >3 cm in diameter. Hum Reprod. 2001;16:2583–6. doi: 10.1093/humrep/16.12.2583. [DOI] [PubMed] [Google Scholar]
- 12.Somigliana E, Infantino M, Benedetti F, Arnoldi M, Calanna G, Ragni G. The presence of ovarian endometriomas is associated with a reduced responsiveness to gonadotropins. Fertil Steril. 2006;86:192–6. doi: 10.1016/j.fertnstert.2005.12.034. [DOI] [PubMed] [Google Scholar]
- 13.Maneschi F, Marasa L, Incandela S, Mazzarese M, Zupi E. Ovarian cortex surrounding benign neoplasms: a hystologic study. Am J Obstet Gynecol. 1993;169:388–93. doi: 10.1016/0002-9378(93)90093-x. [DOI] [PubMed] [Google Scholar]
- 14.Muzii L, Bianchi A, Croce C, Manci N, Panici PB. Laparoscopic excision of ovarian cysts: is the stripping technique a tissue-sparing procedure? Fertil Steril. 2002;77:609–14. doi: 10.1016/s0015-0282(01)03203-4. [DOI] [PubMed] [Google Scholar]
- 15.Hachisuga T, Kawarabayashi T. Histopathological analysis of laparoscopically treated ovarian endometriotic cysts with special reference to loss of follicles. Hum Reprod. 2002;17:432–5. doi: 10.1093/humrep/17.2.432. [DOI] [PubMed] [Google Scholar]
- 16.Barnhart K, Dunsmoor-Su R, Coutifaris C. Effect of endometriosis on in vitro fertilization. Fertil Steril. 2002;77:1148–55. doi: 10.1016/s0015-0282(02)03112-6. [DOI] [PubMed] [Google Scholar]
- 17.Witsenburg C, Dieben S, Van der Westerlaken L, Verburg H, Naaktgeboren W. Cumulative live birth rates in cohorts of patients treated with in vitro fertilization or intracytoplasmic sperm injection. Fertil Steril. 2005;84:99–107. doi: 10.1016/j.fertnstert.2005.02.013. [DOI] [PubMed] [Google Scholar]
- 18.Somigliana E, Arnoldi M, Benaglia L, Iemmello R, Nicolosi AE, Ragni G. IVF-ICSI outcome in women operated on for bilateral endometriomas. Hum Reprod. 2008;23:1526–30. doi: 10.1093/humrep/den133. [DOI] [PubMed] [Google Scholar]
- 19.Sallam HN, Garcia-Velasco JA, Dias S, Arici A, Abou-Setta AM. Long-term pituitary down-regulation before in vitro fertilization (IVF) for women with endometriosis. Art no.: CD004635 Database Syst Rev Issue. 2006;(Issue 1) doi: 10.1002/14651858.CD004635.pub2. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 20.Hauzman EE, Garcia-Velasco JA, Pellicer A. Oocyte donation and endometriosis: what are the lessons? Semin Reprod Med. 2013;31:173–7. doi: 10.1055/s-0032-1333483. [DOI] [PubMed] [Google Scholar]
- 21.Soares SR, Velasco JA, Fernandez M, Bosch E, Remohí J, Pellicer A, et al. Clinical factors affecting endometrial receptiveness in oocyte donation cycles. Fertil Steril. 2008;89:491–501. doi: 10.1016/j.fertnstert.2008.01.080. [DOI] [PubMed] [Google Scholar]
- 22.Diaz I, Navarro J, Blasco L, Simon C, Pellicer A, Remohi J. Impact of stage III-IV endometriosis on recipients of sibling oocytes: matched case-control study. Fertil Steril. 2000;74:31–4. doi: 10.1016/s0015-0282(00)00570-7. [DOI] [PubMed] [Google Scholar]
- 23.Imai A, Takagi A, Tamaya T. Gonadotropin-releasing hormone analog repairs reduced endometrial cell apoptosis in endometriosis in vitro. Am J Obstet Gynecol. 2000;182:1142–6. doi: 10.1067/mob.2000.104804. [DOI] [PubMed] [Google Scholar]