The plot follows newly qualified midwife Jenny Lee and the work of midwives and the nuns of Nonnatus House, a nursing convent, coping with the medical problems in the deprived Poplar district of East London 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.

The story is about a group of midwives based in East London in the 1950s.
       Based on the memoir of Jennifer Worth; the story follows twenty-two year old Jenny, who in 1957 leaves her comfortable home to become a midwife in London's East End slums. She expects to find a hospital, and is surprised to find that the clinic is a convent: Nonnatus House. Working alongside her fellow nures and the medically-trained nun, Jenny has her eyes opened to the harh living condition. But she also discover the warm hearts and the bravery of the mother; each one a heroine in Jenny's eyes.