Blooming Jools Oliver shows off her bump as Jamie reveals he's hoping for a boy

Jools Oliver showed off her baby bump today as husband Jamie revealed that he is hoping for a boy.

The 34-year-old former model - dressed down in tracksuit bottoms and flip-flops - stepped out in Primrose Hill with a friend.

Jools – who is due in March - had to go through intense fertility treatment to conceive the couple’s first daughters Poppy Honey, six, but Daisy Boo, five, and their latest baby were conceived naturally.

Blooming: A pregnant Jools Oliver displays her bump in a nautical style top

‘It would be great to have a boy, as I am in a totally oestrogen-filled house. But I really don't mind as long as it's healthy,’ Jamie said today.

"I won't be suffering too many sleepless nights when the new baby comes because Jools is brilliant about getting the kids into a routine.

'We are very excited, especially as it's not been easy for us to have them,.

Naked chef Jamie, speaking at the launch of his Jamie's Italian restaurant in Bath, also denied he planned to follow Madonna and Angelina Jolie by adopting from overseas.

Healthy glow: Jools' bump is clearly visible as she takes a walk with a friend in Primrose Hill

But he refused to rule out the possibility of adopting an overseas child in the future.

He said: 'I did say I think it's an incredible thing for people to do. I wouldn't rule it out but I am not in talks or anything.'

The British kitchen guru started the rumour mill running this week by admiring Brad Pitt and Angelina Jolie's brood of adopted children.

Jamie, who has cooked for Jolie and Pitt, said: 'If I can't produce a boy I will have to adopt one. I would consider it.

Thrilled: Jools Oliver, who has announced she is pregnant, shows her baby bump off as she picks up her daughters from school in London

We have two beautiful, healthy girls and we cherish them. But I'd be lying if I said it wouldn't be great to have a boy.

'Adoption is such a selfless act and they have a lovely family environment. It's humbling and beautiful to see.

'Jools would like to have another child but there are so many vulnerable orphans out there. Jools and I need to sit down and have a very serious conversation about it.'

Happy family: Jamie Oliver, wife Jools and children Daisy Boo & Poppy Honey attend The Queen's 80th birthday at Buckingham Palace last year

Jamie told how they longed for a big family, but Jools has difficulty conceiving as she suffers from polycystic ovaries.

Earlier this year Jools, his wife of eight years, said: 'I would love more kids but number three is taking longer than I thought. If I have to go through the fertility drugs again, I will.'

Jamie's new chain of restaurants, Jamie's Italian, promise affordable, authentic Italian food served by teenagers from the local area.

There are now branches in Oxford and Bath, with plans afoot to roll the chain out to Kingston, Brighton and Cambridge.

Jamie latest television series, called Ministry of Food, airs on Channel 4 later this month and aims to teach people how to cook from scratch.

High hopes: Jamie and Jools seen shopping near their North London home a few days ago. The couple are hoping for a boy this time

But despite rumours that his work commitments are destroying their marriage, the couple insist they are happier than ever.

In a recent interview Jools said: 'It sounds old-fashioned but I think, when you're with someone like Jamie, you need a wife like me.

'I'm in the background, making sure the kids are in bed and everyone's happy. There is nothing I would rather do.'

As well as looking after the family, Jools has published a book about her problems conceiving, titled 'Minus Nine to One: The Diary Of An Honest Mum'.

Jamie, rumoured to be worth £40 million, recently admitted he was ordered to spend more time at home after working tirelessly on his food empire.

He founded restaurant 15 to train disadvantaged youths, and hit the headlines when he campaigned to improve school dinners.

Jamie added: 'It has taken me years to get my life into perspective. My gang make sure I have a family holiday every summer and I see them every morning.

'I definitely want another child. Jools wants four. At some point, I'll have to start working on that.'

The couple have been married for eight years, during which Jamie has seen his profile soar.

He made his name on BBC2 as the Naked Chef but was poached by Channel 4 in a six-figure deal.

The star also founded the restaurant chain, 15, to train disadvantaged young people.

In recent years he has campaigned on public health issues, notably Jamie's School Dinners which campaigned for the provision of better quality meals for school children.

This year he also criticised the plight of battery farm chickens, even slamming paymasters Sainsbury's for not taking part in a debate about the issue.

The 32-year-old is paid £1.2million to front the supermarket's advertising campaign.

His latest scheme for Channel 4, called Ministry of Food, sees him try to teach the nation how to cook well from scratch.

Despite repeated rumours that their relationship has suffered because of his work commitments, the couple insist they are happier than ever.

Mrs Oliver has said: 'It sound old-fashioned but I think, when you're with someone like Jamie, you need a wife like me.

'I'm in the background, making sure the kids are in bed and everyone's happy. There is nothing I would rather do.'

'Even if I imagine going out with other men, Jamie has got more of what I want. If they were better looking, taller, hunkier, I would still think that Jamie's better.

'He is calm, he is not a worrier, nothing is a problem. All my friends like him, and he is a man's man. He never gives me any worries.'