Reply of the Authors:

Abstract

We thank Dr. Check for his interest in our article. Dr. Check suggested that an alternative to retrieving immature oocytes in women not responding well to exogenous gonadotropins is to use minimal or no gonadotropins. We agree with this statement. It has been demonstrated that in vitro matured oocytes after in vitro fertilization (IVF) can be transferred in the same cycle without the chance of pregnancy being negated (1Chian R.C. Gulekli B. Buckett W.M. Tan S.L. Priming with human chorionic gonadotropin before retrieval of immature oocytes in women with infertility due to the polycystic ovary syndrome.N Eng J Med. 1999; 341: 1624-1626Crossref PubMed Scopus (150) Google Scholar). From our experiences, we found that if the poor responders were pushed to try to obtain mature oocytes by taking high doses of gonadotropins and then hCG to trigger oocyte maturation in vivo, most oocytes retrieved were still at an immature stage (either germinal vesicle or metaphase I). The outcome was very poor, though we occasionally retrieved mature oocytes. In our case report, we did not measure the level of LH; therefore, we do not know whether the level of LH was beginning to rise when we were collecting the immature oocytes. This might be an important point, because it has been indicated that hCG priming before immature oocyte retrieval might improve the quality of oocytes and outcome of in vitro maturation (2Chian R.C. Ao A. Clarke H.J. Tan S.L. Prospective randomized study of human chorionic gonadotrophin priming before immature oocyte retrieval from unstimulated women with polycystic ovarian syndrome.Hum Reprod. 2000; 15: 165-170Crossref PubMed Scopus (295) Google Scholar). Although Dr. Check indicated that the miscarriage rate per sac is significantly higher in those transferring embryos produced from in vitro matured oocytes, we think the final conclusion should be based on more data, especially for poor responders with a proper control group. In addition, recent life-table analysis of data suggests that per natural cycle, the rate of pregnancy does not decline during successive cycles, and thus a decrease in per natural cycle success rate might be offset when more cycles are performed (3Nargund G. Waterstone J. Bland J.M. Philips Z. Parsons J. Campbell S. Cumulative conception and live birth rates in natural (unstimulated) IVF cycles.Hum Reprod. 2001; 16: 259-262Crossref PubMed Scopus (165) Google Scholar, 4Lukassen H.G.M. Kremer J.A.M. Lindeman E.J.M. Braat D.D. Wetzels A.M.M. A pilot study of the efficacy of intracytoplasmic sperm injection in a natural cycle.Fertil Steril. 2003; 79: 231-232Abstract Full Text Full Text PDF PubMed Scopus (19) Google Scholar). Therefore, the efficiency and clinical implication of natural cycle of IVF treatment should be re-evaluated, especially for these poor responders.