The scientist Richard Dawkins has become embroiled in another Twitter row, claiming it would be “immoral” to carry on with a pregnancy if the mother knew the foetus had Down’s syndrome.

The British author made the comment in response to another user who said she would be faced with “a real ethical dilemma” if she became pregnant and learned that the baby would be born with the disorder.

Dawkins tweeted: “Abort it and try again. It would be immoral to bring it into the world if you have the choice.”

@InYourFaceNYer Abort it and try again. It would be immoral to bring it into the world if you have the choice. — Richard Dawkins (@RichardDawkins) August 20, 2014

He faced a backlash for his comment, with one mother, who has a child with the genetic condition, saying: “I would fight till my last breath for the life of my son. No dilemma.”

Dawkins later defended his view, saying he would not apologise “for approaching moral philosophic questions in a logical way”. He went on to point out that Down’s syndrome foetuses are aborted in many cases, and that abortion was a woman’s choice.

Apparently I'm a horrid monster for recommending WHAT ACTUALLY HAPPENS to the great majority of Down Syndrome fetuses. They are aborted. — Richard Dawkins (@RichardDawkins) August 20, 2014

Some users supported the God Delusion author, agreeing with his assertion that there is a difference in deciding on a termination before a child is born, and suggesting after the child is born that it should have been aborted.

The Down’s Syndrome Association (DSA) issued a response to Dawkins’s initial comment. “People with Down’s syndrome can and do live full and rewarding lives, they also make a valuable contribution to our society.

“At the Down’s Syndrome Association we do not believe Down’s syndrome in itself should be a reason for termination, however we realise that families must make their own choice.

“The DSA strives to ensure that all prospective parents are given accurate and up to date information about the condition and what life might be like today for someone with Down’s syndrome.”

Previously Dawkins has caused controversy on Twitter by saying the world’s Muslims had won fewer Nobel prizes than Trinity College Cambridge; and by arguing some types of rape or paedophilia are worse than others, then telling people who couldn’t understand his logic to “go away and learn how to think”.