INTEGRIS Bennett Fertility

We're here for you – every day of the year!

Established in 1985, Bennett Fertility Institute is associated with one of the most experienced private gynecology and obstetrics practices in the state of Oklahoma. The program director, David Kallenberger, M.D., has more than 40 years of extensive experience in the medical and surgical treatment of infertility. The institute's senior physician, Eli Reshef, M.D., is a board-certified reproductive endocrinologist, with more than 30 years of experience in the field.

Bennett Fertility is CAP-certified, and regularly passes a rigorous clinical laboratory inspection. The clinic is an original member of the Society for Assisted Reproductive Technology (SART).

Our nurses, some of them former infertility patients, have extensive experience in managing the complexities of fertility treatments and offer sensitive and compassionate care.

Our clinic is staffed every day of the year, including weekends and holidays, by a physician, a nurse, and a laboratory technician. 

“Hope is the physician of each misery.”

-Irish Proverb



An Introduction: Dr. Eli Reshef

Meet Dr. Eli Reshef, a reproductive endocrinologist & gynecologist and senior physician at Bennett Fertility Institute at INTEGRIS.
An Introduction: Dr. David Kallenberger

Our Doctors

David Kallenberger, M.D.

Infertility, Obstetrics and Gynecology

David Kallenberger


3433 NW 56th St
INTEGRIS Bennett Fertility
INTEGRIS Canadian Valley Hospital



Eli Reshef, M.D.

Infertility, Reproductive Endocrinology Infertility

David Kallenberger


INTEGRIS Bennett Fertility
INTEGRIS Baptist Medical Center
INTEGRIS Canadian Valley Hospital



Laboratory Director

Kellie J. Williams, PhD, HCLD, ELD, TS (ABB)

Education and Board Certification

  • B.S. Biochemistry and Molecular Biology, Oklahoma State University
  • M.S. Biochemistry and Molecular Biology, University of Oklahoma
  • Ph.D. Reproductive Physiology, Louisiana State University
  • American Board of Bioanalysis, Technical Supervisor
  • American Board of Bioanalysis, Embryology Laboratory Director
  • American Board of Bioanalysis, High Complexity Laboratory Director

Your Fertility Journey

Dr. Reshef featured on the cover of 405 magazine

In Vitro Fertilization