Jenny is seconded to a short-staffed hospital in London, but grows increasingly reluctant to carry out her duties when she finds out she is working under intimidating surgeon Mr Tracey. Back in Poplar, the midwives are introduced to newcomer Jane and outspoken twins Meg and Mave Carter. The sisters are identical in every way, except one of them is now pregnant - forcing them to come to terms with the impact a baby will have on them.

Nonnatus House prepares for the annual summer fête, but when a baby show is announced, the girls must find a host for the proceedings. Meanwhile, a patient of Jenny's puts her life at risk, and Sister Bernadette remains troubled.

Sister Julienne and Dr Turner clash over whether to provide a private care service, and a distressing birth raises fears of another Thalidomide case.

Sister Frances finds herself in a tricky situation when a pregnant woman confides in her. Sister Julienne’s new venture hits a stumbling block.

Sister Hilda and Dr Turner are involved with a young woman whose health presents a series of challenges. A complicated pregnancy leads the Nonnatus team on a path of discovery.

It’s July 1966, and Britain is in the grip of World Cup fever. New pupil midwife Nancy makes quite an impact.

With sister Hilda away on a refresher course, sister Julienne steps in to carry out home visits. The new pupil midwives are settling in well, and there is a sense of hope in the air.  While examining expectant mother Vera Sands during a routine visit, sister Julienne is concerned by her toddler daughter who is displaying troubling symptoms. Determined to find out what’s wrong, sister Julienne and doctor Turner are on the case.  Meanwhile, an overly protective mother struggles to cope with her daughter’s teenage pregnancy and is insistent on keeping it low key, much to the frustration of new pupil midwife Nancy Corrigan. 

It’s September 1966, and at clinic Trixie is tasked with examining a desperate woman who is pregnant with her fifth child. Trixie learns that her patient’s personal life is far from stable, compelling her to speak out publicly. However, the results garner mixed reactions from Nonnatus House and the community. Dr Turner and Sister Frances are entrusted to help a mother-to-be who refuses medical care through her final weeks of pregnancy, and Nancy Corrigan reveals a secret about her background that could threaten her relationship with Sister Julienne and Nonnatus House.

Nonnatus House struggles to come to terms with Nancy’s revelation. With Sister Julienne taking her annual leave at the Mother House, Sister Hilda relishes the chance to cover and impress with her leadership. While attending an expectant mother, Sister Frances and Trixie are appalled to learn that Poplar’s housing crisis is worsening, leaving the Nonnatus team vowing to fight for change. It’s a poignant time for the Turner family as Timothy readies to leave for medical school in Edinburgh and Cyril receives news from home, prompting him and Lucille to consider their own future. Meanwhile, a very special baby is born, who causes a rift in a close-knit family and leads many people to count their blessings.

A friend of Chummy's, Reverend Applebee-Thornton, comes to stay at Nonnatus House and soon gets on everyone's nerves. Meanwhile, Jenny and Sister Evangelina deliver a baby with spina bifida, and Sister Bernadette plays matchmaker.

Chummy makes an important decision, Jenny reconnects with Jimmy, and Cynthia's conduct is called into question after the death of a baby she delivered.

Cynthia has to administer daily insulin injections to diabetic John Lacey, a bully who consistently belittles his wife Annie. When Annie’s beloved son Bob pays a visit, Annie gains the confidence to start to turn her life around. Jenny looks after a black mother to be, Monique, who is subjected to racial prejudice from her neighbours.

The convent comes under threat of demolition. Fred's pregnant daughter and her young son come and stay with him. Jenny is wooed by a new love interest. Chummy and PC Noakes prepare for the arrival of their baby.

Barbara treats a pregnant woman whose dockworker husband is struggling to support her as opportunities for work dry up. She is forced into a difficult decision that leaves Barbara facing the biggest test of her career. Nurse Crane meets a kindred spirit when she learns to speak Spanish, and Sister Evangelina helps a woman with breastfeeding, leading to unforeseen consequences.

A outbreak of typhoid erupts, and suspicion over who the carrier could be threatens to break apart a closely knit family. Sister Winfred faces a personal dilemma when a local teacher is revealed to be pregnant by a married man. When the woman takes matters into her own hands, Sister Winifred is forced to consider the role her own prejudices may have played. Meanwhile, Barbara inadvertently agrees to go to dinner with Tom, but is wracked with worry about how Trixie will react.

Sister Julienne is seconded to a maternity ward, and is impressed by how modern technology is being used to help the mothers - but is left with a moral dilemma after assisting on a traumatic birth. A young man from Poplar is delighted to be accepted into university, but his mother is less than happy. His dreams are jeopardised when his girlfriend gets pregnant, a development that puts pressure on the whole family.

Doctor Turner is concerned by the spread of tuberculosis in the community, Jenny tries to repair a father and daughter's fractured relationship, and Sister Bernadette receives devastating news.

Jenny celebrates her birthday with Chummy and the girls, but soon after finds herself taking care of a patient in an abusive marriage.

Poplar is rocked by a series of violent attacks on women, and a prostitute is too ashamed to report what she knows - but her actions lead to a dangerous man roaming the streets, with devastating consequences for the residents of Nonnatus House. A mother tries to keep her daughter's pregnancy a secret to avoid gossip, putting her life in danger. The Turners go on a long overdue holiday, but the weather ruins their plans.

Sister Julienne is drawn into the heart of a different culture when she is called upon to help a Pakistani family. Having come to terms with her own childlessness, Mumtaz Gani is heartbroken when her husband Saddiq brings home a second wife who is eight months pregnant. Sister Julienne must help Mumtaz come to terms with this new addition to her family.

A fun day at the seaside proves traumatic for the Turners and puts May’s future with them in jeopardy. Nurse Crane helps a young couple cope with a rare cancer diagnosis.

Jenny Lee start her midwife career at Nonnatus House in London. She is surprised to find that it is a nursing convent and not a hospital. Her first case is a woman pregnant for the 25th time!

Turner and Shelagh are at the forefront of the advances in medical technology, and begin a campaign to ensure better respiratory health for their patients. However, Timothy fears their own lifestyle is not good for them and tries to encourage his parents to give up smoking. Violet injures her back and is forced to leave the shop in Fred's hands, a decision that strengthens their relationship but which proves to have other, unforeseen consequences. A new mother's past comes to light, with devastating repercussions for her family. Nurse Crane draws on her own experiences to help her.

Dr Turner is horrified to realise he may be partly to blame as the cause of the recent rise in birth deformities comes to light, and tries to prevent further cases. Sister Evangelina returns to work, but has clearly been affected badly by her stroke, and her health continues to deteriorate. A pregnant bride goes into labour during her wedding reception, while her mother is forced to come to terms with her grandchild being conceived out of wedlock.

Sister Monica Joan seeks advice from a clairvoyant. Matthew is shocked to discover squatters in one of his warehouses, and Shelagh faces the most challenging delivery of her career.