Sally Philip’s eldest son, Olly, was 10 days old when he tested positive for Down’s syndrome. Now Sally is concerned that a highly accurate new test to identify the condition will lead to more terminations – and a world without Down’s syndrome.

It has been 12 years since the Miranda actress and her husband, Andrew were told that their baby had Down’s.

“The doctor said to us: ‘I’m sorry, I’m so sorry.’ The nurse on duty cried,” she recalled. “I don’t think anyone said anything at all positive.”

While the condition was dealt with as “bad news,” Sally’s own experience of raising a child with Down’s syndromehas been very different from her initial expectations.

She explained to the Telegraph, “You go home to deal with the “bad news” and you have friends and family who come round and get drunk and talk about the “bad news” and it’s all like something dreadful has happened.”

“And something important has happened and you’re going to have to let go of some of the dreams you had, but it’s really not as bad as everyone makes out.”

“People aren’t fascinated by the things people with Down’s syndrome can do better, which are: relate to people, be funny, be comfortable in their own bodies,” she added.

It is completely natural, then, that Sally is worried about the introduction of a new screening test that has already resulted in the termination of more babies with Down’s syndrome.

The new test – known as non-invasive prenatal testing (NIPT) – works by examining the foetus’s DNA as it circulates in the mother’s blood. The test can detect Down’s syndrome with 99% accuracy, and recent figures show that 9 out of 10 positive diagnosis’ end in a termination.

This week, the BBC will air a one-hour documentary presented and co-written by Sally. In A World Without Down’s Syndrome? Sally asks questions about the ethics of pregnancy screening, talking to expert scientists and people in the Down’s syndrome community.

However, not everyone is happy with Sally’s input into the debate about Down’s and prenatal testing.

Jane Fisher, director of Antenatal Results and Choices, which supports parents affected by foetal screening, told the Observer that the documentary is “not at all helpful” to people who are already facing difficult decisions.

“Sally is a very compelling presenter and – absolutely – it’s great to have the positive images of people [with Down’s] who are already here. But it’s very personal, and it’s an extra layer of difficulty for couples and families who might be making the decision now about whether to end their pregnancy.

“It risks offering the suggestion to those who have [decided to end a pregnancy] that they have made the wrong decision.

“It’s too problematic to have one individual representing that choice – one who is an advocate for not screening, who has a high-functioning, much-loved child. A woman who admits she has the resources for extra help with her absolutely lovely little boy.”

A World Without Down’s Syndrome? will be shownon BBC2 at 9.00pm on Wednesday 5th October 2016.