Pretty much anything involving the workhouses that used to be in the East End. They're never seen, but the effects on those who lived and worked in them are clearly visible. "The workhouse howl" stands out as a Nightmare Fuel.
When Shelagh and Dr. Turner adopt their daughter, the social worker comments that the placement was last minute because the teenage birthmother's parents changed their mind about letting her bring the baby home after the baby was born.
Dr. Turner prescribes thalidomide to a patient, since the side effects weren't known at the time, and she says she'll recommend it to all her friends. So the baby might be born with severe or even fatal birth defects ("Of the approximately 2,000 babies born with defects [in the UK], around half died within a few months"), or the mother's friends' babies if they end up taking it. Also, a few episodes earlier, we saw Dr Turner get really distraught after making a (reasonably fixable) medical mistake. If several babies are born with birth defects because of something he prescribed, he'd feel really guilty. And imagine all the hundreds of real-world doctors who were in that situation. The impact of thalidomide ends up being one of the ongoing plot points of series five and extends into the sixth as well.
In the third episode of season 11, an alcoholic vagrant's gangrenous foot actually falls off while Nurse Corrigan is trying to examine it. Needless to say, the man later dies from blood poisoning.
A few episodes later, a woman in a hippie commune gives birth to a child with gastroschisis - which essentially means being born with one's guts hanging out. Doubles as Nausea Fuel, especially in-universe for Shelagh, who despite her years and years of experience and skill is still left rattled by the incident.
In the season 12 finale, a woman is killed in a car accident while in the early stage of labour. Dr Turner and Shelagh give her a c-section in the middle of the road to save her baby. Made extra upsetting by Shelagh holding the dead woman's hand and tearfully talking to her the way she would to any other patient.
"), or the mother's friends' babies if they end up taking it. Also, a few episodes earlier, we saw Dr Turner get really distraught after making a (reasonably fixable) medical mistake. If several babies are born with birth defects because of something he prescribed, he'd feel really guilty. And imagine all the hundreds of real-world doctors who were in that situation. The impact of thalidomide ends up being one of the ongoing plot points of series five and extends into the sixth as well.