I have been trying to find a less emotionally charged way of explaining the issue to your daughter and others. This may or may not serve.
There are various treatments, medications and screening techniques that pose significant danger to fetal development. As a result, females of childbearing age are asked to take pregnancy tests before healthcare staff proceed with treatment.
It sometimes comes up on mumsnet that a woman is very frustrated that she had to take a pregnancy test, because she couldn't possibly be pregnant; perhaps she's had a hysterectomy, gave birth the previous day or is 73 years old. The poster says that surely healthcare staff could use personal discretion.
The problem is, this is a nation of over 60 million, half of those female, and most of whom will reach adulthood, have the capacity to become pregnant, and need medical treatment between menarche and menopause. The NHS employs thousands of HCPs. The moment you remove this blanket policy, and place it in the hands of individual employees to get it right with every patient they see, you guarantee that a woman who could be pregnant won't be asked to test her urine.
The easy cases will remain easy: the women who have had complete hysterectomies, gave birth the previous day or are 73 years old.
But what about the edge cases?
Like 12 year old girls who haven't even had their first period yet? However, you ovulate before you menstruate. You can get pregnant without having ever menstruated, if you get pregnant during your first cycle. Approximately 1 in 10 girls is sexually abused before her 18th birthday. So unfortunately the possibility exists that one of the 12 year old patients you'll be treating during your career is being sexually abused, and is in the early stages of pregnancy. You can't know which one.
Women experiencing regular periods, on their period right now, can't be pregnant, right? Wrong. Some women continue to experience break-through bleeding on a regular cycle during pregnancy. You cannot know which one isn't actually having a genuine period.
Your next patient is Sandy. Sandy has had three failed IVF cycles and thinks it's an insult to be asked to wee on a pregnancy stick. However, a teeny, tiny number of women will get pregnant naturally after IVF treatment. If 1 in 10,000 women get pregnant naturally after IVF treatment, that's like winning the lottery. No point hoping for it as an individual. But the people at the National Lottery meet lottery winners every week. So do healthcare staff, because thousands of people visit the hospital every week, too. The woman unknowingly pregnant with a miracle pregnancy, will walk through the doors along with 9,999 women who were right when they said they couldn't be pregnant.
Next you see Diane. Due to a clerical error, it says on her records that she's had a hysterectomy to deal with unexplained bleeding, so you don't ask her to test her urine. Actually, her records are supposed to say she's had a hysteroscopy which is when someone has a look inside a uterus to identify the cause of unexplained bleeding. Her uterus is most definitely still there!
Emma comes in. She assures you she hasn't had sex in the last year. What she doesn't know, or is unwilling to accept, is that she had her drink spiked at a house party last month and she was raped while unconscious.
Liz comes in. She's 51 and thinks she's moved out of perimenopause and into menopause. She tells you she's not had a period for seven months, and before that they were extremely irregular. This is true. But she ovulated four weeks ago and she is now in the early stages of pregnancy.
And so on.
These seemingly unlikely edge cases are why we have blanket policies. If it is left up to personal discretion, someone, somewhere will make the wrong decision, with lifechanging consequences.