Colour of Cardi B's placenta and umbilical cord leaves fans with questions

After giving birth to her fourth child, Cardi B decided to commemorate the special occasion in a very unique way involving the placenta and umbilical cord... and people naturally have a lot of questions.

The 33-year-old rapper gave birth to a son on 4 November, her fourth baby and the first with partner and New England Patriots wide receiver Stefon Diggs.

She already shares three children - Kulture, Wave and Blossom - with ex-husband Offset.

Last week (19 November), the mum shared the first pictures of the youngster on Instagram, whose name is yet to be revealed.

In one, she can be seen cradling her sleeping son in a nursery, while another shows Cardi and Diggs with their new baby in the hospital room, with the youngster's face blurred in the picture.

"11/4," Cardi wrote in the caption, alongside emojis of a teddy bear, heart and American football.

To celebrate the birth of her latest child, the 'I Like It' rapper had a piece of her placenta encapsulated and her umbilical cord cast into a gold chrome heart.

The process was done by Mommy Made Encapsulation, a company that has encapsulated the placentas and moulded the umbilical cords of many mums and celebrities - including the likes of Megan Fox and Chrissy Teigen.

To create the unique keepsake, the baby's umbilical cord was dehydrated and moulded into the shape of a heart, before being dipped in gold chrome'.

Cardi also opted to get a print made of her placenta.

In a video shared by the company, an expert can be seen forming a heart with the cord.

Speaking to PEOPLE, Mommy Made Encapsulation CEO Juliane Corona said: "Our team was honoured to be trusted with such a meaningful part of her birth experience.

"At Mommy Made Encapsulation, our goal is to help mothers improve their postpartum recovery and to help families preserve a special part of their postpartum journey through safe and professional placenta service."

But the vibrant dyed blue colour of the umbilical cord and placenta has left fans with a lot of questions.

Multiple Instagram users took to the comment section to ask: "Why is it blue?"

Meanwhile, others offered up potential reasons behind the blue shade, with one person suggesting: "I think the food dye to do the imprint before rinsing and cooking."

As another added: "I think she decided on blue because this baby is a boy."

And a third did some research before writing: "I went to their page. Once the blood is washed off, they painted them and make a print that goes into an entire gift package they send the new mommy.

"I saw one that was like rainbow coloured."