Reply of the Authors

Abstract

It is correct that, as we already discussed in our article (1Oktay K. Türkçüoğlu I. Rodriguez-Wallberg K.A. Four spontaneous pregnancies and three live births following subcutaneous transplantation of frozen banked ovarian tissue: what is the explanation?.Fertil Steril. 2011; 95: 804.e7-804.e10Abstract Full Text Full Text PDF Scopus (64) Google Scholar), pregnancies do happen after hematologic stem cell transplantation, but they are rare. Although it is still possible that the pregnancies reported in our article could have happened with or without the ovarian transplantation, it is highly unlikely.First, the patient was menopausal for 2.5 years, as confirmed by her high follicle-stimulating hormone levels. Second, the patient was sexually active during the period leading to the ovarian transplant, but she did not conceive. Third, the patient conceived shortly after the ovarian transplantation; she had four consecutive pregnancies that resulted in three livebirths in a span of 5 years and 8 months. Finally, there has been accumulating evidence on the ovarian niche and its impact on regeneration of putative germ stem cells (2Oktay K. Goswami S. Darzynkiewicz Z. Manipulating ovarian aging: a new frontier in fertility preservation.Aging (Albany NY). 2011; 3: 19-21PubMed Google Scholar, 3Niikura Y. Niikura T. Tilly J.L. Aged mouse ovaries possess rare premeiotic germ cells that can generate oocytes following transplantation into a young host environment.Aging (Albany NY). 2009; 1: 971-978PubMed Google Scholar).Furthermore, previous studies have shown no benefit of hormone replacement therapy on spontaneous pregnancy rates in women with premature ovarian failure or primary ovarian insufficiency (4Van Kasteren Y.M. Schoemaker J. Premature ovarian failure: a systematic review on therapeutic interventions to restore ovarian function and achieve pregnancy.Human Reprod Update. 1999; 5: 483-492Crossref PubMed Scopus (265) Google Scholar). For that reason, we do not think that the resuming ovarian function, albeit intermittent, had a role in the establishment of our patient’s pregnancies. The work ongoing in our research laboratory and studies by others will soon shed light on the mechanism of the clinical observations we reported in the article. It is correct that, as we already discussed in our article (1Oktay K. Türkçüoğlu I. Rodriguez-Wallberg K.A. Four spontaneous pregnancies and three live births following subcutaneous transplantation of frozen banked ovarian tissue: what is the explanation?.Fertil Steril. 2011; 95: 804.e7-804.e10Abstract Full Text Full Text PDF Scopus (64) Google Scholar), pregnancies do happen after hematologic stem cell transplantation, but they are rare. Although it is still possible that the pregnancies reported in our article could have happened with or without the ovarian transplantation, it is highly unlikely. First, the patient was menopausal for 2.5 years, as confirmed by her high follicle-stimulating hormone levels. Second, the patient was sexually active during the period leading to the ovarian transplant, but she did not conceive. Third, the patient conceived shortly after the ovarian transplantation; she had four consecutive pregnancies that resulted in three livebirths in a span of 5 years and 8 months. Finally, there has been accumulating evidence on the ovarian niche and its impact on regeneration of putative germ stem cells (2Oktay K. Goswami S. Darzynkiewicz Z. Manipulating ovarian aging: a new frontier in fertility preservation.Aging (Albany NY). 2011; 3: 19-21PubMed Google Scholar, 3Niikura Y. Niikura T. Tilly J.L. Aged mouse ovaries possess rare premeiotic germ cells that can generate oocytes following transplantation into a young host environment.Aging (Albany NY). 2009; 1: 971-978PubMed Google Scholar). Furthermore, previous studies have shown no benefit of hormone replacement therapy on spontaneous pregnancy rates in women with premature ovarian failure or primary ovarian insufficiency (4Van Kasteren Y.M. Schoemaker J. Premature ovarian failure: a systematic review on therapeutic interventions to restore ovarian function and achieve pregnancy.Human Reprod Update. 1999; 5: 483-492Crossref PubMed Scopus (265) Google Scholar). For that reason, we do not think that the resuming ovarian function, albeit intermittent, had a role in the establishment of our patient’s pregnancies. The work ongoing in our research laboratory and studies by others will soon shed light on the mechanism of the clinical observations we reported in the article. An explanation for the true origin of spontaneous pregnancies after subcutaneous ovarian transplantationFertility and SterilityVol. 95Issue 7PreviewTo the Editor: Full-Text PDF