They have been dubbed "sharents" – the mums and dads who blog, tweet and post pictures from their children's lives – often simultaneously. If you're not one yourself, you've probably come across one, perhaps even taken advantage of apps such as Unbaby.me, which helpfully replaces the endless feed of baby pictures with images of cats or, if you prefer, bacon. Because sharents have a tendency to get a little … carried away.

Mostly aged 35 and upwards, they were early adopters of social media who quickly became comfortable sharing their thoughts with strangers. Now, as they enter parenthood, it seems natural to take everyone along with them, every step of the way. On STFU, Parents, a blog that "mocks examples of parental overshare", photographs of a child's vomit ("This is what I had to clear up today!") and a mother showing off her own placenta almost make one nostalgic for the days of annual round-robin newsletters.

But how will this parental sharing affect children as they grow up? That photo of your son playing the angel Gabriel might be cute when he's four but will he be bullied about it a few years later? Do you want his mum's account of him wetting the bed still out there when he becomes prime minister? "The problem with digital footprints," says Tony Anscombe of the internet security firm AVG, "is that it's difficult for an individual to control that information once it's out there. When it comes to our children, we're making the decision to put things out on their behalf, and what seems appropriate now may not be appropriate in ten years' time."

One can't help wondering how the son of the American blogger Nerdy Apple will feel when he's older and still haunted by his mother standing up for his decision to go to a party as Daphne from Scooby-Doo with a post titled "My son is gay". Or how much time the son of Canadian blogger Buzz Bishop will spend on the psychiatrist's couch in the wake of his dad telling the world that his older brother is his favourite child. The psychologist Aric Sigman agrees that we should be concerned: "Part of the way a child forms their identity involves having private information about themselves that remains private. That is being eroded by social media. I think the idea of not differentiating between public and private is a very dangerous one."

The medium too is something of a problem. In person, it may be possible to explain to a grown-up child that their birth was a shock but was not something you regretted – reading a public post written at the time and detailing strong emotions is a rather different proposition. In 2009, Shellie Ross used Twitter to report the death of her young son just hours after the event, prompting as much criticism as sympathy online. "The written word doesn't always lend itself to emotional nuance," says Sigman. "A particularly personal episode may not come across in the way it was intended."

Some parents have already started thinking more carefully about the online presence they have given their children. Anne Bruce grew uncomfortable about what she had posted when a number of work acquaintances befriended her on Facebook. "I was concerned that I could come across as mumsy and unprofessional and also began to worry about compromising the children's safety – that photos could get into the wrong hands." But she was reluctant to give up an effective way of sharing pictures with relatives abroad, so instead set the children up on their own accounts with just a small number of (generally related) "friends". "It's not strictly within the rules of Facebook because they're only one and five and aren't supposed to have accounts but as I see it, the accounts are just my pseudonyms."

But opting out altogether is not that easy, as Natalie Lisbona, who lives in north London, knows. She is one of only two parents she knows who does not share information about their children online. "I wonder where these pictures will end up. I wonder what the information will be used for and how my girls will feel about me handing it over," she says. But she caved in and put up a couple of photos a few months ago. "I suppose I just wanted to prove I'm a good mum," she says. "I worry that by not mentioning my kids, people will think I'm not interested in them and don't do things with them. I put up a photo of them and it got 30 'likes' … I couldn't help feeling proud. But I'm trying to avoid posting anything else. I think the girls will respect me for it when they're older and still have their privacy."

Others feel that the advantages of sharenting far outweigh any negatives. In an increasingly fragmented society, social media allows us to stay connected to friends and family, and get support that for many is not easily accessible. Blogging was a lifesaver for Sophie Walker when her daughter, Grace, now 11, was diagnosed with Asperger's syndrome. Feeling isolated, she started writing at courage-is.blogspot.co.uk "to make sense of what was happening to us, to give my daughter a voice and to find out if anyone else could offer advice or at least a sense of solidarity".

It turned out there were hundreds of other parents in the same situation. Grace has been involved since the beginning and reads every entry her mother writes. "I don't ever write anything she's not comfortable with and I self-censor a lot of our experiences. But I wanted to tell people how fabulous she is and show her too in the process." Dealing with a diagnosis such as autism can be very lonely, says Walker: "You get pushed out of the normal parenting groups and social situations. Blogging kept us in touch with people like us and gave us the support and confidence that helped us cope."

Aimee Horton just wanted her blog Pass the gin to provide a realistic counterpoint to all the "perfect parents" she came across online. Keeping up with the Joneses today often means painting a picture of a family life more idyllic than the Waltons, all sun-dappled Instagram scenes and tweets about making cupcakes together. "Perhaps some people truly love all elements of motherhood but there's a less represented group of us who love our children to bits but are very glad when they go to bed," says Horton, who documents her struggles trying to get planking toddlers into car seats and dissuading her son from having the Spiderman logo shaved on to the back of his head.

She is breezy about online footprints – "inevitable" – and plans to keep blogging until "it doesn't feel right any more. But I'd like to think it will stay there as a record when the boys are older. I'd never want to damage my children's confidence, and if it made them feel uncomfortable then of course I'd take things down. But if it's just a little bit embarrassing … well, they're going to have to learn to laugh at themselves at some point."

The desire to document our lives is nothing new. But where does the need to publish it stem from? Why is the approval of strangers so important? Horton believes it's different for every sharent. "Some people do it for money, some people do it for support, to reach out – it's therapy in some ways. Some are showing-off. But every person out there on social media is after recognition of some sort and anyone who claims otherwise is lying.

"People want recognition that they have a perfect life or, if you're me, that you're not the only person who has to clean your children's poo off the floor."

'I record what makes me laugh'

Emma Beddington with her sons. Photograph: Graham Turner for the Guardian

I'd have to be an outrageous hypocrite to rail against other people's children online. I write a personal blog and it often features my sons: their weird enthusiasms, their idiosyncrasies, their repeated requests that I look at a picture of a man selling advertising space on his neck goitre in the Ripley's Believe it or Not! annual.

I like to think that I only write about them when there's something interesting to say. I'm probably wrong, but at least you can choose whether to read a parenting blog. I do: my favourites, The Harridan and Relentless Laundry, are witty and brilliantly frank about the humiliations and tedium of life with small children, while brimming with evident love and affection for their offspring. I love the writing; it reaches across the internet and reassures you you're not alone.

Facebook is different. I've never posted a picture of my child on it and it transpires that was wise, because my best friend would have disowned me.

"I hate it. It's the blight of social media," she hisses when I raise the subject. "A plague of red-faced potato babies. You're allowed one picture. That's all."

"Are baby pictures really worse than Instagram shots of artfully frothed coffee?" I ask her.

"I might think 'ooh, I'd like to try that cafe'. I do not want to try out that baby. I am not 'friends' with the baby".

I like Facebook babies in the same way I like pictures of other baby animals: because they are intrinsically comic and charming, however tuber-like. I also like them because each one reminds me that I no longer have to monitor another human being's bowel movements on an hourly basis.

I get twitchy, though, at status updates vaunting a child's precocious block-stacking or shape-sorting exploits, partly because I know I'm prey to that temptation too. We all think our kids are wonderful, obviously, and the occasional thrill of vainglorious pride we feel at their achievements spills out in a humblebrag or a boastful status update to our bored acquaintances. It's ghastly, yes, but it happens in real life too. The internet isn't to blame – it has just made the phenomenon horribly ubiquitous.

What about the kids themselves? This is uncharted territory: the internet is a world away from the yellowing photograph albums of our own childhoods. I don't use my kids' real names on my blog and I try to avoid writing anything that would have mortified me growing up, but might they resent me later? I'm sure they will. I resented my own parents on far flimsier grounds (unwillingness to buy me purple suede pixie boots, for instance).

I hope, too, that they'll recognise the love behind it: I record what makes me laugh and what makes me proud: the things that make me glad I had them in the first place. Emma Beddington

belgianwaffling.com

Tips for sensible sharenting

Research by AVG, an internet security firm, claims that more than a third of British children have had images of themselves uploaded to social media by their parents and that the average infant now acquires a digital footprint before their first tooth. The popular habit of posting ultrasound images to announce a pregnancy means the adults of tomorrow could potentially be traced all the way back to the womb from which they sprung.

But who would bother doing that? "That's what we don't know yet," says Tony Anscombe, of AVG. In the US, where sharenting is even bigger, there have been reports of teenagers going to apply for driving licences, only to find someone has already got a licence in their name and been banned.

Anscombe predicts that identity theft is likely to increase as we share more about children. Even taking the precaution of using only a child's first name online, it's surprisingly easy to put together the pieces of the jigsaw, he says.

• Check privacy settings – do you still own the content? Who has access? Many of us give away more than we realise. Sites such as mypermissions.org display the third parties to whom you've granted access to your Facebook and Twitter accounts. Adjustyourprivacy.com lets you change settings on all accounts and opt out of online tracking.

• Set up a Google Alert in your child's name; use a search-aggregator such as 123people.co.uk to find out what information can be collated about them. The Social Safe app brings all your social-media timelines together.

• Find help for parents on Quib.ly, a new Q&A website