St Mary's Hospital was founded in 1790 as the Manchester and Salford Lying-in Hospital, being established through the efforts of Charles White, Richard Hall, and Edward Hall. Charles White was already an obstetrician of international repute and was surgeon at Manchester Infirmary. However, the decision to found a new charity was taken without consulting the MRI Board, and the ensuing dispute resulted in the resignation of Charles White from the Infirmary. The hospital was originally named the Lying-in Charity for home deliveries and Lying-in Hospital, although the hospital had no accommodation until 1791. Charles White gave lectures to the midwives of the charity and to pupils. The training of midwives was emphasised, and it has been claimed that it was one of the first hospitals in England to undertake this task. The hospital's first site was a rented house on Salford Bridge (now Victoria Bridge). Inpatient accommodation of approximately 20 beds was intended for married women who had been deserted, recently widowed, or whose homes were unfit for childbirth. Far larger numbers of patients were attended by midwives in their own homes. Later an out-patient service began for women in early stages of pregnancy or suffering from child-birth related disorders, and for children under the age of two.
In 1795 the hospital moved to larger premises at the Bath Inn in Stanley Street, where there were a number of wards, but it is unknown how many beds. Like the Infirmary, the hospital had private baths sourced from a local spring; bathers were charged for use and the profits went to the charity. The hospital performed Caesarean sections, taking part in the ongoing controversial debate about the procedure. The charity was often in financial difficulties, and the rising costs of treating in-patients, led to attempts to reduce the numbers of in-patients. Rules were more stringently applied and in 1813 the in-patient department was abandoned. Female midwifery pupils could now stay with the midwives in the hospital, and accompanied them on rounds. In the early nineteenth century, the hospital also was involved in small-pox vaccination. The charity wanted to move to smaller premises, but had found it difficult to sell the building. In 1819 they managed to rent out the house in Stanley Street and move to 18 King Street, a much smaller building. The hospital remained here for less than three years, before returning to Stanley Street in 1822. In 1820, the charity extended its area to include Hulme, Chorlton Row, Ardwick, Miles Platting, Collyhurst and parts of Salford, and later allowed admission of children up to the age of seven. This change necessitated an increase in the numbers of male and female mid-wives, and Thomas Radford was appointed as a man-midwife for out-districts. In 1828, term man-midwife was replaced with surgeon. The name of the hospital was changed to the Lying-in Hospital and Dispensary for Disease of Women and Children in 1822. The hospital suffered continuing financial difficulties and ever increasing patient numbers. From 1835, pregnant patients were required to pay, if able, two shillings upon admission.
In 1840 the hospital moved again to South Parade, Manchester. Unfortunately a fire at South Parade in 1847 destroyed much of the hospital's property and the hospital had to operate from the Eye Hospital next door. A 'museum' of specimens which had been collected by Charles White and given to the Lying-in Hospital in 1808, was largely destroyed in the fire. Subscriptions were falling rapidly in the 1840s, and a Ladies' Committee was organised in 1849 to raise funds. Thomas Radford wanted the hospital to provide general medical service to women and children of Manchester and be a place of medical education. In 1853, Radford gave his library to the hospital and began lectures for medical students. Radford led a campaign for a new hospital, supported by the Ladies' Committee. He had a national reputation and long record of service, and had some influence over the trustees. A new building with twelve beds for cases of dangerous labour was completed in 1852, but conditions were still cramped and the hospital was seen as insanitary.
In 1854 the name was changed to 'St Mary's Hospital and Dispensary for the Diseases peculiar to Women and also for the diseases of Children under six years of age'. This was a reference to the nearby church, but the name also more accurately reflected the reduced domiciliary midwifery service and expanded outpatients clinics for women's diseases. The hospital still required more space, the new hospital in Quay Street opened the following year, with about thirty beds for children and sixty for women. There was a steady rise in subscriptions; the out-patient service became an important part of hospital work and the midwifery aspect was played down. In the 1850s a satellite service was begun in Pendleton, Salford. Despite evident successes, there were conflicts among the medical and honorary staff, resulting in the resignation of four of the six ordinary surgeons. One of the places was filled by Charles Clay, a surgeon famous for conducting the first ovariotomy. His lectures helped St Mary's gain recognition by the examining boards. Various schemes were proposed to extend the charity, involving mergers with MRI or the Children's Hospital. From 1867, however, the income of the hospital began to increase consistently, as did the number of in and out patients. The 1870s saw the end of the system of recommendations and a domination of St Mary's by non-maternity cases.
Medical education at St Mary's was consolidated in 1883 when Owens college awarded a lectureship to Dr Lloyd Roberts, who had set up a cancer department at the hospital. C.J. Cullingworth was appointed to succeed Thorburn as professor of Clinical Midwifery and Diseases of Women. In another development, midwives who trained at the hospital were awarded a certificate for attending lectures and passing examinations and in 1905, St Mary's became an approved school for the training of midwives. Since the 1880s, St Mary's had been planning to expand, and in 1890 the hospital bought a site on Gloucester Street (now Whitworth Street). A proposal was made that they merge with the Southern Hospital, but this was unsuccessful, partly due to rivalry between the hospitals. In 1899 the building began, but the new premises in Whitworth St only opened in 1904. The hospital amalgamated with the Southern Hospital in 1904 to form the St Mary's Hospitals. A new building of the Southern Hospital was completed in 1910 on the Owens College Estate, and became the gynaecology and children's department. The Whitworth Street site was used for Maternity cases, although most maternity cases were still seen at home. After the 1911 National Insurance Act, St Mary's reduced the size of the district it served and ceased to employ midwives. By 1938, home deliveries only accounted for a quarter of midwifery cases, the rest were at the hospital under the care of doctors and medical students. This period saw an increase in popularity of hospital delivery. In 1919 a clinic for the treatment of venereal disease was commenced at St Mary's and 1923 saw the establishment of ante-natal clinics. The accommodation for these clinics was found by transferring the Radford Library to the University of Manchester. However, there was still demand for more space for maternity beds. Some land was purchased and extensions to the High Street Branch were made in 1936, and the same year a convalescent home was opened in a large house in Victoria Park, but this did not solve the problem. The 1930s also saw a closer relationship between St Mary's and MRI, leading to an efficient use of space and resources.
The Whitworth Street site was closed in 1939 as it was a likely bombing target, although the domiciliary service was still based there. Patients were moved to the High Street Branch and other hospitals. This necessitated the creation of branch hospitals, including Collar House in Prestbury, and later the adjacent Prestbury Hall. Although these branches originated from a war time emergency measure, they remained open until 1952. Adlington Hall was used from 1941 until 1946 as accommodation for the wives of men serving in the forces, patients coming from all over the country. With the advent of the NHS, St Mary's became part of United Manchester Hospitals, a group of teaching hospitals. Whitworth Street was reopened in 1949, but was out-of-date and plans were made for a new maternity hospital. These plans only became possible in the 1960s when a large new building was built next to the old St Mary's building on Hathersage Road. Whitworth St was demolished in the 1970s and the Hospital was concentrated on the Oxford Road/Hathersage Road site. A large number of gynaecological and obstetrical pioneers were based at St Mary's for some point in their careers, including Charles White, John Hull, Thomas Radford, Charles Clay and Charles James Cullingworth. The hospital remains a pioneer in obstetrics and gynaecology, and has more recently earned a widespread reputation in paediatrics.