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Your Fertility Team

Compassionate Assistance for Growing Families

At our clinic, our caring staff is genuinely dedicated to helping couples achieve their goals of becoming parents. Our commitment to our patients and their families shows in almost everything we do. Our staff takes the time to understand your situation, and we create fertility plans based on what is best for you.

Michelle Bigelman PA-C; MMS

Dr. David Kreiner, MD

Dr. David Kreiner, MD, graduated with Cum Laude honors and AOA distinction from Downstate Medical School in 1981, marking the beginning of a distinguished career in reproductive endocrinology and infertility (REI). His passion for helping individuals and couples build their families through in vitro fertilization (IVF) was ignited in 1977, the year the first IVF baby was born. This groundbreaking moment occurred during his first year of medical school, inspiring Dr. Kreiner to dedicate his life to the field of IVF.
In November 1980, while still a fourth-year medical student, Dr. Kreiner undertook a rotation in REI under the mentorship of a recent Johns Hopkins REI fellowship graduate, Dr. Zev Rosenwaks. It was then that Dr. Kreiner proposed the idea of establishing the first IVF center on Long Island to Dr. Rosenwaks. Despite the initial skepticism, citing the unique success of the only IVF center in the U.S. at the time in Norfolk, Virginia, Dr. Kreiner was undeterred. He chose to pursue his residency in Stony Brook, NY, under Dr. Rosenwaks, who later became the Medical Director of the Jones Institute, the American pioneer program in IVF, in 1983.
Dr. Kreiner's dedication to the field was further demonstrated during his fellowship in Norfolk in 1985, where he earned several awards for his research on endometriosis, PCOS, and IVF. After completing his fellowship and spending a year as an Assistant Professor, Dr. Kreiner realized his vision by founding the first successful IVF program on Long Island in 1988, Long Island IVF.
Following the establishment of Long Island IVF, Dr. Kreiner continued to enhance his expertise and contribute to the field of fertility. Over the years, he has gained invaluable experience, keeping abreast of the latest technological and methodological advancements in reproductive medicine. His commitment to excellence and patient-centered care has helped countless individuals and couples navigate the complex journey of fertility, offering them hope and support every step of the way.
Dr. Kreiner is thrilled to join the Palm Beach Fertility Center, viewing it as an exciting new chapter in his career where he can continue to make significant contributions to the field of reproductive medicine. His decision to join the center is fueled by a desire to leverage his extensive experience and passion for helping more individuals and couples achieve their dream of parenthood in a new community. Dr. Kreiner looks forward to bringing his expertise, innovative approaches, and compassionate care to the Palm Beach Fertility Center, furthering their mission to provide exceptional fertility services.

Michelle Bigelman PA-C; MMS

Michelle Bigelman PA-C; MMS - Physician Assistant

Michelle Bigelman brings over 20 years of experience as a Board-Certified Physician Assistant specializing in Women’s Health, Fertility, Obstetrics, and Gynecology. She is passionate about optimizing patient’s lifestyles to help their fertility. She enjoys integrating elements of mind-body connection, nutrition, and stress management into her practice and always focusing on the individual patient and their health and wellbeing goals. Michelle earned her Bachelor of Science degree in Nutrition at University of Georgia, and her Master of Medical Science and Physician Assistant degrees from Midwestern University in Chicago with highest distinction. She is certified by the National Commission on Certification of Physician Assistants.

In addition to practicing medicine, Michelle is a certified yoga instructor. Outside of work, Michelle loves spending time with her three children and husband, wearing out her energetic dog with long walks, practicing yoga, and sipping that first cup of hot coffee in the morning.

Blanca I. Duque

Blanca I. Duque, TS/ALT/MT (ABB) - Laboratory Supervisor, Embryologist, Andrologist

Blanca has been working as an embryologist/andrologist since 1996, and she joined Palm Beach Fertility Center in 2005. Passionate about learning, Blanca completed a Masters in Endocrinology and Techniques of Assisted Reproduction IVI in Valencia, Spain.

She is proficient in all aspects of embryology, including:

  • Embryo biopsy for PGT (Preimplantation Genetic Testing)
  • Embryo and oocyte freezing and thawing
  • Intracytoplasmic sperm injection (ICSI)
  • Culture Semen analysis and freezing
  • Preparation of sperm for IUI, TESA and MESA

Certified as a medical technologist with the American Association of Bioanalysts (MT AAB), Blanca is also a technologist supervisor with the American Board of Bioanalysts (TS ABB). She is licensed in Florida as a laboratory supervisor and holds membership in the American Society for Reproductive Medicine (ASRM). Blanca has contributed to medical publications in Colombia, Spain, and Germany. Fluent in English and Spanish, Blanca enjoys reading, swimming, and walking. She is also a Reiki Master and Energy Healer since 2000.

Estrella Rosemberg, MSc, ELD, TS (ABB)

Estrella Rosemberg, MSc, ELD, TS (ABB) - Laboratory Supervisor, Embryologist, Andrologist

Estrella joined Palm Beach Fertility Center Embryologist team in 2015. She received her Master’s Degree in Physiology of Reproduction at Cornell University, New York City in 1984. She also did a fellowship in the Valencian Infertility Institute (IVI). Since that time, Estrella has been working as an Embryologist, Lab Director, IVF lab Consultant in all basic and advanced IVF techniques including micromanipulation, embryo grading and vitrification of oocytes, ovarian tissue, and embryos. She has extensive experience with andrology lab work, sperm preparation for IUI, sperm DNA fragmentation, and sperm bank management.

She is an expert in embryology staff training, laboratory management, and quality control. She has also participated in numerous international IVF conferences as a panelist and presenter.

She wrote 2 chapters in the book Embryo and Oocyte Cryopreservation. Estrella serves as the Supervisor Representative to The American Association of Bioanalysis Southern Regional Board of Governors. Estrella is licensed in Florida as Laboratory Supervisor in Embryology and Andrology. Licensed Embryology Laboratory Director (ELD) and Technical Supervisor of Andrology and Embryology (TS) by the American Board of Bioanalysis, and a Member of the American Society of Reproductive Medicine. (ASRM)

Lisa K. Perdue

Dr. Lisa K. Perdue - Acupuncturist

Dr. Lisa K. Perdue is a Japanese American Acupuncturist. She holds board certifications from the National Certification Commission for Acupuncture and Oriental Medicine, Kiiko Matsumoto Style Japanese Acupuncture Practitioner, Certified Laser Provider, and Medical Qigong Practitioner. Since 2000, Dr. Lisa has treated a wide range of medical and health concerns with advanced training in fertility, autoimmune disease, PTSD, pain management, sports-specific injuries, women’s health, and laser therapy. She is one of the few practitioners integrating laser technology for fertility, along with reproductive medicine.

Kristine Rose Gruber, BSN, RN - Nurse Manager, IVF Coordinator

Kristine completed her first bachelor’s degree in health science studies at Stony Brook University in Long Island, NY. She then pursued her studies at Hartwick College in Oneonta, New York, where she graduated Magna Cum Laude with a bachelor’s degree in nursing. In the initial phase of her nursing career, Kristine worked in a hospital setting, caring for critical cardiac patients before transitioning into Women’s Health. She began her career as an IVF nurse in New York City, where she served for the past 5 years before relocating to South Florida. In 2022, she joined the Palm Beach Fertility team and currently holds the position of Third-Party Reproduction Coordinator. Kristine understands the intricacies of coordinating treatment cycles that involve a third party, such as an egg donor or gestational surrogate. Owing to her meticulous attention to detail and compassionate nature, she acts as the primary contact for all third-party treatment cycles. She continually aims to deliver the highest level of care. Her enduring goal as a nurse is to always advocate for her patients, ensuring their care needs are consistently met.

Kari Ratty - Patient Care Coordinator

Kari Ratty - IVF Coordinator

Kari graduated from Keiser University of West Palm Beach with an Associate Degree in Medical Assisting. In 2009, Kari was introduced to Dr. Mark Denker and Palm Beach Fertility Center through her externship with Keiser University. Due to Kari’s work ethics and outgoing personality, we were thrilled to take her on as a permanent member of our team at the clinic.

Kari is responsible for assisting Dr. Denker during exams and procedures, as well as medication injection teaching and phlebotomy. She works closely with our patients to help them with the emotional highs and lows of fertility struggles. Kari is a mother of 2, and wants to help others experience the joy of having a family of their own.

Eliza Roberts - Practice Manager, Financial Counselor

Eliza Roberts - Practice Manager, Financial Counselor

As the Practice Manager, Eliza has been contributing to the success of Palm Beach Fertility Center since 2007. In addition to her role as Practice Manager, she is a Certified Medical Assistant and maintains her knowledge by attending fertility conferences throughout the year. She is also the Administrative Liaison on the Florida Society of Reproductive Endocrinology and Infertility Board of Directors. She works closely with Dr. Mark Denker to ensure patients receive the best care.

She is your go-to person who "makes it happen." Eliza recognizes that financial considerations are very important to our patients. Understanding insurance benefits and obtaining the necessary referrals or authorizations can be cumbersome, confusing, and frustrating. This is why Eliza is always furthering her education to bring new and informative information to you and Palm Beach Fertility Center.
Eliza is available to explain the costs of fertility treatment and to make it as stress-free as possible. She strives to find new, affordable, and personalized treatment plans for each patient.

Jessica Villano - Administrative Assistant

Jessica Villano - Assistant Practice Manager, Specimen Transport Coordinator.

Jessica joined Palm Beach Fertility Center in 2016. She coordinates authorizations, referrals, surgery scheduling, financial consults, and transfers for specimens. Jessica loves to be challenged with opportunities to learn and grow.
She anticipates patient needs by understanding how fertility treatments can be difficult and stressful. With her compassionate, professional service and infectious enthusiasm, Jessica strives to exceed patients’ expectations.

Ksenia Korovyakovskaya - Aventura Digital Marketing

Ksenia Korovyakovskaya - Aventura Digital Marketing

Ksenia is our Digital Marketing expert for Aventura Fertility & IVF. She currently specializes in medical marketing. Ksenia has experience in digital marketing strategy, vendor relations, strategic planning, execution and promotions. She develops relationships with the local OB GYN doctors and other professional and business groups. She increases our digital footprint & web visibility in the Miami- Dade & Southern Broward counties.

Fertility Care as
Unique as Your DNA

Anyone trying to conceive without success knows that infertility can consume your life. Dr. Mark Denker, M.D., R.E., and the compassionate team at Palm Beach Fertility Center understand that nothing matters more to you than building a family. We devote ourselves to helping resolve infertility with individualized care that produces optimal results.

About Palm Beach Fertility