Call the Midwife's Shelagh cares for man in iron lung in first look

"Two years after our wedding, he caught polio," Betty tells Shelagh.

"I'm not a churchgoer but I made a bargain with God. I said, 'If you save my Owen, I will never complain about anything again'. He may be paralysed from the neck down, he can't even breathe without this contraption, but he's never once complained. Nor have I."

"Don't listen to her, she complains all the time," Owen joked, before Shelagh notices something odd.

In the following scene, Betty looks in a compact mirror and says that, stood next to Shelagh, she does look "a little bit yellow".

"I could be mistaken, but I do wonder whether you could be jaundice," says Shelagh, before Betty reveals that she once had jaundice when she had gallstones.

As Shelagh looks to arrange a visit from Doctor Turner, Betty looks worried. Will everything be okay?

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In Sunday night's episode (2nd February), there is plenty going on in Poplar as a solo delivery puts Sister Julienne's skills to the test as she must "find the strength to help the mother through a traumatic birth whilst overcoming her own personal crisis".

Elsewhere, the synopsis continues: "The Nonnatus team oversee the care of a man living inside an iron lung, and Violet decides to create the Poplar Commonwealth Games in an official, safe capacity and enlists the help of Cyril, who has returned from Jamaica."

Call the Midwife airs on Sundays at 8pm on BBC One and BBC iPlayer.

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