When pregnant singer P!nk sat down with a decaf coffee recently and posted a witty Instagram caption about using her coffee break as a chance to sit on the floor and rest, she probably didn't expect to be slammed in the comments for apparently putting her baby's health at risk.

"You got to wean yourself off of some things you love for the sake of the baby,” wrote one commenter, and others agreed.

“She shouldn’t be drinking coffee of she wants a healthy baby!” said another.

Other people didn't attempt to hide their disdain at her choice of beverage. “Feeding addictive stimulants to an unborn baby. Well, that’s your choice,” wrote one affronted commenter.

P!nk, 37, real name Alecia Moore, is expecting her second child with her husband, professional motorcross racer Carey Hart.

She pointed out that the coffee was in fact decaffeinated, writing in the caption: "When microwaving your decaf coffee becomes an excuse to sit on the floor and rest for a while.... #help #reststop #illjustbehereifyouneedme."

Lots of other commenters - both mums and non-parents - rushed to her defence.

"Take as many breaks and drink coffee if you want to!" wrote one.

"I have 6 children, drank soda while pregnant with every one of them and they are all perfectly healthy! If you want a little caffeine, drink it and enjoy it," said another (despite the fact that P!nk said her coffee was caffeine-free).

Another pointed out that some people just seem intent on judging mums. "Mom shamers are a whole other breed of a**holes. I still drink regular coffee," she wrote.

"One cup won't harm the baby at all. Some people are just huge sanctimommies [sic]. I mean, hers is even decaf! Internet trolls."

'Sanctimommies' is a term some Internet users have coined to refer to sanctimonious mothers who judge other parents' choices.

Several Facebook groups exist for self-confessed sanctimommies - as well as parody groups.

NHS guidelines don't recommend cutting out caffeine completely for pregnant women - instead, they advise limiting your intake to 200mg, or the equivalent of two small cups of instant coffee a day.

But let's not forget - P!nk's coffee was the decaf variety!

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