Display options
Share it on

Facts Views Vis Obgyn. 2015;7(2):119-26.

A comparison of the use of clomiphene citrate and letrozole in patients undergoing IVF with the objective of producing only one or two embryos.

Facts, views & vision in ObGyn

B I Rose, D C Laky, S D Rose

Affiliations

  1. Infertility Solutions, P. C., 1275 South Cedar Crest Boulevard, Allentown, PA 18103. ; Department of Obstetrics and Gynecology, St. Luke's University Health Network, 801 Ostrum Street, Bethlehem, PA 18015.
  2. Infertility Solutions, P. C., 1275 South Cedar Crest Boulevard, Allentown, PA 18103.

PMID: 26175889 PMCID: PMC4498169

Abstract

AIM: The objective of this study was to compare the use of clomiphene citrate and letrozole in an IVF setting in which the objective was to produce only one or two embryos. Either clomiphene citrate or letrozole was used in conjunction with gonadotropins without the use of GnRH antagonists.

METHODS: Sixty-two patients received either clomiphene citrate or letrozole with low dose gonadotropins in 128 non-randomized treatment cycles. HCG was given when one follicle was at least 17 mm. Oocyte retrieval was done 34 hours later and fertilization was performed using ICSI.

RESULTS: There were no statistically significant differences in the number of large follicles produced, oocytes fertilized, endometrial thickness, clinical pregnancy rates, or delivery rates in patients taking letrozole compared to clomiphene citrate. More mature oocytes were retrieved after clomiphene citrate, but a subset analysis of patients undergoing both treatments did not support this difference. The only statistically different finding in both analyses was the peak estradiol levels during treatment, which averaged 516 pg/ml with letrozole and 797 pg/ml with clomiphene citrate (p = 0.005). Overall, the cancellation rate due to a premature LH surge was 5%. An average of 2.8 mature oocytes were recovered, 2.1 oocytes fertilized and 1.6 embryos were transferred. The overall clinical pregnancy rate per transfer was 25% (95% confidence interval 17.7% to 33.3%) and the overall live birth rate per transfer was 19.2% (95% confidence interval of 11.6% to 26.8%).

CONCLUSIONS: Other than peak estradiol levels, there were no clinically significant differences when letrozole or clomiphene citrate was used for mild ovarian stimulation for IVF. There were only rare cancellations because of premature LH surges.

Keywords: IVF; clomiphene citrate; letrozole; mini-IVF; minimal stimulation IVF; natural cycle IVF

References

  1. Hum Reprod. 2006 Nov;21(11):2845-9 - PubMed
  2. Hum Reprod. 1996 May;11(5):917-9 - PubMed
  3. Reprod Biomed Online. 2009 Sep;19(3):343-51 - PubMed
  4. Fertil Steril. 2010 Aug;94(3):888-99 - PubMed
  5. Hum Reprod Update. 2009 Jan-Feb;15(1):5-12 - PubMed
  6. Fertil Steril. 2011 Oct;96(4):1051-6 - PubMed
  7. Facts Views Vis Obgyn. 2014;6(3):150-5 - PubMed
  8. Hum Reprod. 2012 Mar;27(3):881-8 - PubMed
  9. J Clin Invest. 1998 Jun 15;101(12):2622-9 - PubMed
  10. Fertil Steril. 2005 Jan;83(1):110-5 - PubMed
  11. Hum Reprod Update. 2002 Mar-Apr;8(2):129-39 - PubMed
  12. Hum Reprod. 2007 Nov;22(11):2801-4 - PubMed
  13. Hum Reprod. 2007 Apr;22(4):980-8 - PubMed
  14. Int J Fertil. 1992 Nov-Dec;37(6):339-42 - PubMed
  15. Fertil Steril. 2006 Nov;86(5):1428-31 - PubMed
  16. Fertil Steril. 1999 Apr;71(4):639-44 - PubMed
  17. Fertil Steril. 2010 Nov;94(6):2167-71 - PubMed
  18. Fertil Steril. 2011 Jul;96(1):95-101 - PubMed
  19. Fertil Steril. 2009 Jun;91(6):2501-7 - PubMed
  20. Fertil Steril. 2011 Jun 30;95(8):2449-55 - PubMed
  21. Hum Reprod. 1990 Aug;5(6):670-4 - PubMed
  22. Hum Reprod. 1992 Sep;7(8):1154-8 - PubMed
  23. Hum Reprod. 2006 Jul;21(7):1884-93 - PubMed
  24. Reprod Biomed Online. 2014 Mar;28(3):310-20 - PubMed
  25. Hum Reprod. 2010 Nov;25(11):2678-84 - PubMed
  26. Fertil Steril. 2000 Jan;73(1):90-3 - PubMed
  27. Fertil Steril. 2014 Jun;101(6):1574-81.e1-2 - PubMed
  28. Reprod Biomed Online. 2014 Mar;28(3):265-6 - PubMed
  29. Reprod Biomed Online. 2014 Mar;28(3):267-72 - PubMed
  30. Fertil Steril. 2002 Feb;77(2):384-6 - PubMed
  31. Hum Reprod. 2001 Feb;16(2):259-62 - PubMed

Publication Types