Dr. Fritz Friedrich Fuchs, a New York obstetrician and gynecologist who advanced the knowledge and treatment of the female reproductive system, died on Feb. 17 at a hospital in Hamburg, Germany. He was 76 and lived in Manhattan.

A spokeswoman for Cornell University Medical College, where he performed much of his research, said the cause was a stroke. He was in Germany accompanying his wife, Dr. Anna-Riitta Olsson Fuchs, a chemist who frequently collaborated with her husband, on her sabbatical from Cornell at the University of Hamburg's Institute for Hormone and Fertility Research.

Dr. Fuchs was noted for his research on the endocrinology and physiology of human reproduction. Endocrinology is the study of the form, function and treatment of the endocrine system, the network of glands that secrete hormones that affect the workings of organs.

He was best known for developing an effective intravenous agent to prevent premature labor and for his pioneering work with amniocentesis to detect fetal genetic disorders. He also helped introduce the laparoscope for routine use in gynecological practice in this country. The laparoscope is a tube that can be inserted through a small incision to view the internal organs or do surgery.