On developing a thesis for Reproductive Endocrinology and Infertility fellowship: a case study of ultra-low (2%) oxygen tension for extended culture of human embryos

J Assist Reprod Genet. 2017 Mar;34(3):303-308. doi: 10.1007/s10815-017-0887-5. Epub 2017 Feb 4.


Fellows in Reproductive Endocrinology and Infertility training are expected to complete 18 months of clinical, basic, or epidemiological research. The goal of this research is not only to provide the basis for the thesis section of the oral board exam but also to spark interest in reproductive medicine research and to provide the next generation of physician-scientists with a foundational experience in research design and implementation. Incoming fellows often have varying degrees of training in research methodology and, likewise, different career goals. Ideally, selection of a thesis topic and mentor should be geared toward defining an "answerable" question and building a practical skill set for future investigation. This contribution to the JARG Young Investigator's Forum revisits the steps of the scientific method through the lens of one recently graduated fellow and his project aimed to test the hypothesis that "sequential oxygen exposure (5% from days 1 to 3, then 2% from days 3 to 5) improves blastocyst yield and quality compared to continuous exposure to 5% oxygen among human preimplantation embryos."

Keywords: Blastocyst; Embryo development; Fellowship training; In vitro fertilization; Medical education; Oxygen tension.

Publication types

  • Review

MeSH terms

  • Blastocyst / metabolism
  • Blastocyst / physiology
  • Embryo Transfer / methods
  • Endocrinology*
  • Fellowships and Scholarships
  • Humans
  • Infertility / physiopathology*
  • Mentors
  • Oxygen / metabolism
  • Physicians
  • Reproductive Medicine / education*
  • Reproductive Medicine / trends
  • Reproductive Techniques, Assisted*


  • Oxygen