The singer – who is expecting twins with her husband Nick Cannon – believes all parents should be celebrated, especially those who have had “difficult pregnancies”.

She said: “I have so much respect for mothers everywhere, especially those who’ve had difficult pregnancies or given birth to multiples.

“We need to have Mother’s Day once a week!”

The ‘Dreamlover’ hitmaker was speaking as she posed without a top and exposed her baby bump for Life & Style magazine, and she confessed she was terrified about the photo shoot.

She said: “I was feeling very vulnerable about taking pictures at all right now, but then I didn't want to miss this opportunity to document this once-in-a-lifetime experience.

“My ultimate goal was to share this incredibly personal moment with my true fans."

However, it was not easy as the baby girl was kicking during the modelling session.

She added: “The babies were kicking almost the entire time; it was unbelievable.

“Especially the girl – clearly she’s a diva in training! We didn’t start shooting until 1.30am because I was in the hospital from the night before until the day of the shoot with contractions five minutes apart.”