'That baby's poor neck, hold your child properly... more important than a selfie!' Model famed for her incredible six-pack during pregnancy sparks backlash after posting a photo of her 13-day-old son

Fitness guru and model Chontel Duncan has defended herself on social media after she posted a photo of her 13-day-old son lifting his head.

The Brisbane resident took the photo in the mirror, holding her phone with one hand and her son, Jeremiah Thomas, with the other. 

Jeremiah, who was swaddled in a soft blue wrap, had his head lifted off Chontel's chest, prompting a mixed reaction from her 477,000 Instagram followers.

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Mixed reaction: Chontel Duncan posted this photo with her son Jeremiah Thomas - prompting an online debate over the way 13-day-old Jeremiah held his head

'Hold ur child properly': Some people expressed concern over the photo, saying Jeremiah was not being held properly and worried about the support for his neck

'I'm concerned on how you're holding the baby,' one person wrote.

'Omg that babys poor neck. Hold ur child properly! More important than a selfie [sic],' wrote another.

The response prompted Chontel to re-post the photo alongside a similar shot of Jeremiah, this time resting his head on her chest.

Defending herself: Chontel defended the photo, which she said captures the moment her son lifted his head off her chest for a 'second'

'More important than a selfie': The photo prompted some social media users to express their concerns over how the baby was being held

Fit mum: Chontel continued to train throughout her pregnancy, and at 37-weeks-pregnant, shared videos of herself kickboxing and doing strength sessions

'I'm not going to be nice about what I think about your belittling attempts to educate me on the safety or better yet my intentions as a new mum,' Chontel wrote.

'As explained earlier Miah lifted his head up an for that second that he did so, I just happened to have caught it on camera, before he then laid his head back down on my chest. 

'New borns can lift their own heads up its not me standing there with his head flicked back shooting away... So have faith people and if you honestly don't like my page just click unfollow. [sic]' 

In a previous post Chontel spoke of her son's strength, writing: 'he is extremely alert and very strong shocking the staff here with his arms and neck strength'. 

Baby love: 'Newborns can lift their own heads up its not me standing there with his head flicked back shooting away,' she said

'My son did exactly the same thing when he was a baby': Chontel also had her fair share of supporters, who said there was no cause for concern and their babies had done something similar

Despite the negative comments, Chontel also had the support of many of her followers.

'Wow people really need to get over this and have some faith,' one person wrote.

'As if a mother is going to put their newborn in danger just for a photo.'

Another agreed, saying their child had done something similar as a baby.

'You shouldn't have to explain yourself to anyone,' they wrote, 'but my son did exactly the same thing when he was a baby.'

A mother's love: Chontel welcomed her son, Jeremiah Thomas, on Good Friday 

Baby bumps: She rose to fame after sharing this photo, that shows 'two ladies 4-5 weeks apart in their pregnancies'

'She's doing absolutely nothing wrong': Chontel had the support of many of her followers who shared similar experiences and defended her photo

Chontel is not alone in being criticised for the way she holds her baby.

Gold Coast mother and fitness guru Sophie Guidolin, who continued to workout until she was 34 weeks pregnant, appeared on The Today Show after she gave birth to twin girls: Evie and Aria. 

Some viewers took to the program's Facebook page to express concern about the way Mrs Guidolin held them. 

Cause for controversy: Gold Coast fitness guru Sophie Guidolin appeared on The Today Show after she welcomed her twin girls - but viewers expressed concern over how she held her daughters

Online debate: 'Might do well to support bub's head better, just a tip from the unfit,' one social media user wrote

No reason for concern: Despite the negative comments, a leading obstetrician said there was 'no problem' with how she was holding her babies

'Might do well to support bub's head better, just a tip from the unfit,' one social media user wrote, before adding 'I just wanted to reach into the tv and grab em off her [sic].'

'I was thinking the same thing!! I know that babies are pretty resilient but she just seemed to care more about her fame than her tiny babies!' another said.

On Instagram, Ms Guidolin received a flood of support from fans. 

Leading obstetrician and former president of the Australian Medical Association, Dr Andrew Pesce, says he has 'no problem' with the way Ms Guidolin held the twins.