You’ll need to prepare for endless nappy changes, sleepless nights, and all the anxieties that go with the territory of being a new mum or dad.

However, your finances also feel the effect and, while most new parents have a good idea about the obvious costs to expect, it’s the unexpected ones that can really dent your bank balance.

New research from Mothercare for example, has found that parents drive an astounding 1,322 miles each year in a bid to get their newborns to sleep (the equivalent of one and a half times the distance between Land’s End and John O’Groats) at a cost of £547 in petrol – something our first case study, Helen Robinson, knows about all too well.

We talk to her and two other new mums about the unexpected costs of parenthood and ask for their first-hand tips on how to manage them.

Mum-of-two, Helen Robinson, knows only too well the unexpected costs a baby can bring. She spent a small fortune on petrol when driving her first baby, Theo, now 2, around the local streets of Newcastle in a bid to send him to sleep and now often takes newly-arrived Effie too…

“I often used to drive around to get Theo to sleep as he was colicky and sometimes nothing else worked,” says Helen, 31. “The motion of a car is a great way to get babies to sleep when they are very young, especially if they are fretful and you've tried everything else.”

She continues: “I’d drive around 20 miles most evenings to get Theo to sleep until he was about three months old, and now I sometimes drive them both around during the day, so I have probably spent quite a lot on petrol.”

Another kind of fuel – heating the home – has also proved an unexpected cost of Helen’s. “Obviously I’m in the house a lot more than when I was working, so the heating is on throughout the day.

"And, when it's really cold, I have to have the heating on at night too as I have to get up to feed Effie. I ran up heating bills of almost £300 in just five weeks! In addition to this, the tumble dryer and washing machine are now on all the time and the children have baths every night which also increases bills.”

It’s natural for new mothers to want to join in local classes but Helen found they worked out more expensive than she thought. She says: “I did three terms of water babies with Theo costing £375, plus new swim shorts for each term as baby clothes don’t last long. That was my most expensive class but it was one of many.”

Helen’s tip: “Make sure you are not sucked into buying things you don’t need. It’s easy to throw money at any product that promises to solve your problems, for example teething gels/granules/medicine/teething rings. But remember it’s also very easy to sell 'miracle solutions' to sleep deprived mums!”  

Self-employed business advisor, Kirsty McKenzie gave birth to daughter Isla four months ago. But her and partner Jake, from Hoylake on the Wirral, Merseyside, started to get organised as soon as Kirsty discovered that she was pregnant…

“In the months before Isla’s birth, I cleared out our house and sold EVERYTHING we didn't use on eBay. The money I made was then reinvested into essential baby equipment,” says Kirsty, 38.

“Jake and I joke that we have a second-hand baby as we bought nearly everything second-hand too including clothing, the cot and furniture for her nursery.  The clothes still had tags on though, I wouldn't have anything fabric that had been worn.”

Kirsty also took advantage of online baby clubs run by the manufacturers of baby products which offered some useful giveaways. She also looked out for sales and purchased cheap items ahead of when they would need them.

However, the fact she got some wrong translated into unexpected expense.

“I bought clothes that Isla never wore as I didn't expect friends to be so generous,” she says. “I had bought her a ‘capsule wardrobe’ when she was born but she weighed 10lbs 6oz so couldn't wear any of her newborn dresses anyway.

"In fact I soon came to realise that dresses for newborns are totally impractical and it's much easier for them to live in babygrows that are cheap and can be washed and changed a thousand times a day!”

Thankfully, Isla’s swing seat was borrowed by Kirsty and Jake and not bought for the £90 price tag as she simply will not sit in it.

Once on maternity leave, Kirsty took Isla to all the free events run by the library and children's centres. “I limited my own treats to lunch out a maximum of twice a month and coffee out once a week.

"I also walked everywhere to save on costs as well as to try to work off the baby weight and help get Isla to sleep.”

While breastfeeding for the first four months saved money on food, when Kirsty decided to move over to bottles Isla wouldn’t take them. “I then spent a fortune trying to find ones she would tolerate and, of course, she chose the imported bottles which are very expensive! I could never have accounted for that.”

Kirsty’s tip: “Preparing for Isla’s arrival would have cost us hundreds or thousands more if I’d been too proud to take second-hand items, didn’t have such lovely friends and hadn’t sold on eBay like a mad woman!”

New mum, Becca Campbell had Oscar just five weeks ago but she and her partner, Colin have already run into a number of unexpected costs...

The first cost was the most basic need of all, as 28-year old Becca explains: “Before Oscar was born I had planned to breastfeed but when that didn’t work out we had to put him on formula.

"We were on a tight budget and this meant suddenly finding money for new bottles, teats, steriliser and bottle warmers.” The formula is costing the new parents an extra £40-£50 a month, which could easily double as Oscar increases his feeds.

Becca and Colin, who live in Claughton on the Wirral, Mersyside, also discovered that their current car may no longer be adequate. Becca explains: “We bought a £260 car seat but discovered it can only be fixed into cars that have Isofix points – and this is only standard issue in cars manufactured from 2006 onwards which ours wasn’t.

For now it’s not an issue as we have a seat that can be attached with a seat belt but when Oscar gets slightly bigger, the £260 seat is going to be useless unless we get a new car – it’s annoying!”

There were smaller but equally frustrating extra costs too. For example Oscar’s microwavable steriliser doesn’t fit their current microwave so the couple will need to fork out for another one.

Becca and Colin also found they had too much baby kit for the future rather than for the here and now: “Surprisingly, we didn't have enough newborn clothes,” says Becca.

“Most things we had bought and been given are much too big for him so we had to buy newborn clothes that will fit him now.”

Other small things the couple hadn’t budgeted for included a rain cover for the car seat and a sling to carry Oscar in while Becca heals from her caesarean. “It’s another small thing but, at £35, it all adds up when you’re on maternity pay,” she says.

Becca’s tip: “It’s easy to assume that everything is going to be just as you planned but, as we found with Oscar, it doesn’t always happen this way. Therefore you should save as much as you can before the baby is born and build up a pot you can dip into for unforeseen costs.”