Meet Beth Israel’s Outstanding Team of Fertility Care Specialists

Peter L. Chang, M.D.
F.A.C.O.G., Director

Dr. Chang completed his fellowship in Reproductive Endocrinology at Columbia University, College of Physicians & Surgeons, where he remained as Assistant Professor before joining Beth Israel Medical Center.

His research has centered on infertility, premature ovarian failure and Polycystic Ovary Syndrome. He is board-certified in Obstetrics & Gynecology and in Reproductive Endocrinology & Infertility. He is also an Assistant Professor at Albert Einstein College of Medicine of Yeshiva University.

Dr. Chang is a member of numerous professional organizations, and has written chapters for medical texts and more than sixty published scientific papers and abstracts in the fields of Obstetrics & Gynecology and Reproductive Endocrinology.

He has been recognized by the numerous publications as one of the top physicians in his field, for evaluating and treating women with infertility as well as recurrent miscarriages, including the following:

Consumer’s Research Council of America
Listed in “America’s Top Obstetricians and Gynecologists”

The New York Times
Listed in “Super Doctors”

Castle Connolly Medical, Ltd.
Listed in “New York Metro Area’s Top Doctors”

U.S. News & World Report’s - Top Doctors”

Top Reproductive Endocrinologists on the list of U.S. News & World Report’s Top Doctor”


Doron S. Stember, M.D.

Doron S. Stember, M.D. is a specialist in male fertility and sexual medicine at Beth Israel Medical Center and Assistant Professor of Urology at Albert Einstein College of Medicine. Dr Stember works closely with Dr. Chang in the treatment of couples seeking pregnancy. "Male factor" infertility accounts for, or contributes to, subfertility in nearly half of all cases.

Dr. Stember attended medical school at New York University School of Medicine. He subsequently completed his urology residency at Mount Sinai Medical Center. Following residency, he completed two years of fellowship of fellowship training in male reproductive medicine, microsurgery, and sexual medicine at the Center for Reproductive Medicine & Microsurgery at Cornell and Memorial Sloan-Kettering Cancer Center.

Dr. Stember's clinical practice is focused on the medical and surgical treatment of male subfertility, sexual dysfunction and low testosterone. He has special interest and training in minimally invasive and microsurgical techniques for surgical sperm retrieval in obstructive and nonobstructive azoospermia, microsurgical varicocele repair, vasectomy, vasectomy reversal, erectile dysfunction treatment including penile prosthesis implantation, testis prosthesis insertion, treatment of Peyronie's disease, and testosterone replacement therapy.

Dr. Stember was the recipient of prestigious Scholars in Sexuality Research Grant Award from the Society for Sexual Medicine in 2010. He has authored more than 40 articles, book chapters and abstracts in the field of reproductive and sexual medicine. His research and discoveries have been presented at national and international conferences and published leading journals including The Journal of Urology, Annual Review in Medicine, and the Journal of Sexual Medicine. He is a co-author of the forthcoming textbook, "Clinical Care Pathways in Andrology."

Dr. Stember sees patients at Phillips Ambulatory Center at 10 Union Square East (please call 212-844-8900 to schedule an appointment). He accepts most insurance plans.


Stephan Quentzel, M.D.
Director, Primary Care Psychiatrist

Dr. Quentzel is a psychiatrist and family-care physician at the forefront of the movement to integrate sound mental health care into ambulatory medical services. He currently provides psychiatric care for the Center as well as the large outpatient obstetrics and gynecology department.

He received his medical degree from the University of Illinois after completing his undergraduate work at the Massachusetts Institute of Technology, and completed both his family practice and psychiatry residencies at Beth Israel Medical Center.


Carlo Acosta, B.S.

Mr. Acosta studied at the Jones Institute in Norfolk, VA, and at Cornell University. He has more than 25 years of human embryology experience and expertise in micromanipulation techniques. He also developed embryoplasty™ and performs it with the highest expertise.

His expertise in advanced microscopic processes has led his laboratory to achieve some of the region’s highest success rates.


Yan Zhang, R.N.
Clinical Coordinator

Ms. Zhang received her doctorate of medicine in China, and has extensive experience with all aspects of infertility testing and treatment, including in-vitro fertilization and egg donation.

She is in charge of coordinating all aspects of our fertility care methods. Ms. Zhang is also fluent in Chinese.


Ruth Gabay, M.S.
Certified Social Worker

Ms. Gabay has practiced for eleven years, specializing in women’s health. She has consistently remained active within the community, running several groups for women dealing with infertility, and is involved with numerous organizations for infertility education and advocacy.

She is currently a senior social worker at Beth Israel and consults with patients individually and in groups for issues of infertility, pregnancy, and pregnancy losses.

Ms. Gabay received her master’s degree in social work from the New York University School of Social Work after completing her undergraduate studies in Psychology and Education at Yeshiva University.

To speak with one of our care specialists, contact the Center for Infertility and Reproductive Health today and schedule a consultation.