The plot follows newly qualified midwife Jenny Lee and the work of midwives and the nuns of Nonnatus House, a nursing convent, part of an Anglican religious order, coping with the medical problems in the deprived Poplar district of London's desperately poor East End in the 1950s. The Sisters and midwives carry out many nursing duties across the community. However, with between 80 and 100 babies being born each month in Poplar alone, the primary work is to help bring safe childbirth to women in the area and to look after their countless newborns.