‘Cruel’ note angers women across the nation

It can be rare to receive a card in the mail these days, so when you do it's often something important.

But that hasn't been the case for scores of women in the US who have bizarrely received cards from a "Jenny B" congratulating them on their pregnancy - despite the fact that in most cases, they're not even expecting.

The strange correspondence, which has been shared by multiple women on social media from all across America, involves a card with a tagline "holy guacamole! You're going to avo baby!" being sent to them, often to their parents' or family home address.

A message inside written in black texta reads: "Congratulations!!! I'm so excited for you! I hope you like these. (Love) Jenny B."

Inside are gift card and coupons for a range of baby product brands associated with company Mother's Lounge and a receipt for them valued at $US250 ($A365).

It's unclear whether the gift cards can be genuinely used.

The company, which is based in Utah, seems to be targeting women from a mailing list regardless of whether they are pregnant or not.

For many women, it's led to an uncomfortable conversation when their parents have opened the card and mistakenly believed they were pregnant.

Julia Hellman told The Independent receiving the card was "very disturbing", and she "knew it was some sort of scam" so wouldn't even try to use the coupons and gift cards.

Writer A.P. Hawkins' card was sent to her parents' house, and she had asked her mother to open it for her over the phone, resulting in an uncomfortable denial that she was pregnant.

"My mum's first thought was that it was some weird or cute way of me announcing I was pregnant," she told The Washington Post.

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Receiving something so personalised that was actually an elaborate marketing ploy also left Ms Hawkins feeling upset when she got off the phone with her mother as there is "so much emotion tied up in pregnancy".

But she believes women struggling with infertility could be feeling much worse.

"I feel like that would be a really traumatising thing, to have someone write to you and say, 'Oh hey, you're pregnant'," Ms Hawkins said.

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Another Twitter user, Lauren Jones, said she had to "talk my mom down off a ledge" after a card from Jenny B was sent to her home address.

According to The Independent, Mother's Lounge was behind another mass marketing campaign that sent similar letters in February this year. The business is which is purported to be run by a woman named "Jenny Bosco" which is presumably where the "Jenny B" comes from.

After an investigation by the Surry County Sheriff's Office in Virginia, the February campaign "does not appear to be a scam", the office said in a statement issued on Facebook at the time.