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 experiencein the medical and surgical treatment of infertility. The institute's medical director, Eli Reshef, M.D., is a board-certified reproductive endocrinologist, with more than 30 years of experience in the field.

The laboratory director, J.W. Edward Wortham, Jr., Ph.D., HCLD, has more than 40 years of experience in laboratory medicine and serves as an inspector for the reproductive laboratory accreditation program of the American College of Pathology (CAP)

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 medical director of 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

J.W. Edward Wortham Jr., Ph.D., HCLD

Education and Board Certification

  • B.S. Arkansas State University
  • M.S. Arkansas State University
  • Ph.D. Southern Illinois University
  • American Board of Bioanalysis, High Complexity Laboratory Director, 1994
  • American Board of Biola, Embryology Lab Directory

Your Fertility Journey

Dr. Reshef featured on the cover of 405 magazine

In Vitro Fertilization