Gabriella Morreale was born on 7 April 1930 in Milan, the daughter of the Sicilian biologist and diplomat Eugenio Morreale and the Milanese Emilia de Castro, also a biologist. She lived in Vienna and Baltimore before moving to Malaga at the age of 11. In 1953 she married the Spanish doctor and surgeon Francisco Escobar del Rey, becoming a Spanish citizen.
Morreale dedicated his life to the study of the role of iodine and thyroid hormones in foetal and infant brain development. In the 1970s he initiated the routine measurement of TSH and thyroid hormones in heel blood of newborns to prevent mental deficiency due to untreated congenital hypothyroidism. Simultaneously, she demonstrated the importance of maternal thyroid hormones and the mother's access to iodine in foetal brain development, helping to define the nutritional iodine requirements of pregnant women. Together with her husband, Francisco Escobar del Rey, she led numerous epidemiological studies in all regions of Spain that have provided in-depth knowledge of the problem of iodine deficiency and its psychosocial consequences, and its correction through the introduction of iodised salt in the 1980s. According to Juan Bernal and M.ª Jesús Obregón of the Instituto de Investigaciones Biomédicas Sols-Morreale in Madrid, "His work has had a great impact on public health actions that have prevented thousands of cases of mental retardation".
Morreale spent time at the Department of Endocrinology of the University of Leiden (Holland) at the invitation of Professor Andreas Querido. In 1957 she joined the CSIC as a scientific collaborator at the Centro de Investigaciones Biológicas and, as a scientific researcher, she founded the Thyroid Studies Section of the Instituto Gregorio Marañón (1963-1975). In 1975, as a research professor, she moved with her group to the Faculty of Medicine of the UAM, where she remained active until she was 80 years old, the last years of her life as a doctor associated ad honorem.
She conducted her research in endocrinology together with the physician and surgeon Francisco Escobar del Rey, who was also her husband. In 1976, she initiated with him a nationwide prevention programme for mental deficiency due to congenital hypothyroidism based on the heel prick test, which allowed early diagnosis and treatment with thyroid hormone of children who, had they not been treated, would have inevitably developed profound mental deficiency. A few years later, Unicef adopted the test and began to apply it worldwide, and since 1990 the WHO has included iodine consumption during pregnancy and early childhood in its table of entitlements.
Morreale has trained numerous scientists in the field of thyroid hormone endocrinology, both from a basic and applied point of view. According to his biography, it can be said that experimental and molecular endocrinology was born in Spain by his hand, together with his excellent collaborators.