His twin brother, Manfred Guttmacher, was an advisor to the Baltimore City's Supreme Bench as a psychiatrist.
Their older sister, Dorothy Emma Guttmacher, owned the Tudor Flower Shops at Johns Hopkins Hospital.
Alan married Leonore Gidding in 1926 and together they raised three daughters, Ann (Loeb), Sally (Holtzman), and Susan (Green).
He served as Director of Obstetrics and Gynecology and was appointed Obstetrician and Gynecologist-In-Chief at Mount Sinai Hospital in New York for approximately ten years.
He extended this endeavor by founding the Association of Planned Parenthood Physicians which included scientists and medical practitioners.