Sleep-deprived parents of newborn babies can only dream of getting a good night's rest.
In those early weeks, red-eyed mums and dads know that their small babies will be waking regularly for feeds. But for some parents, the sleep deprivation doesn't end there. It can continue for months and even well into the pre-school years.
Ultimately, parents tend to have their own methods for getting their baby to sleep. Elton John (63), who recently became a dad to baby Zachary with partner David Furnish (48), is suffering from sleep deprivation.
"We have a rocking chair in his room and the best thing in the world is rocking him to sleep, it's like no other feeling in the world," he said.
Sleep expert Wendy Dean, who is a mum of four, says that when it comes to sleep deprivation: "When you have got a newborn I think you kind of expect it.
"But when you are six months down the line and still getting four or five hours a night, it seems exceptionally debilitating."
It's not just parents who suffer due to erratic sleeping patterns. The baby can be grouchy during the day, too.
Dean, who is the author of a popular book entitled The Baby Sleep System, sees many Irish people looking for advice on her website Baby Sleep Answers.
She says that it is generally a set of circumstances that have come together that gets people "into a bit of a pickle".
For example, some babies are rocked to sleep or fed to sleep at the beginning of the night -- the baby falls asleep on the breast or the bottle. The mum lays them down, and that often works quite effectively in the early weeks, she says.
"So you will find mums have good sleeping babies, and usually around four months old, it becomes more of a problem that they keep waking up. That is because babies sleep in cycles as do adults, and if they wake, if they had a prop at the beginning of the night, for example the feed or rocking, they need the same prop in order to get back to sleep again.
"They have two different types of sleep as well, a light sleep and a deeper sleep. They tend to be in a lighter sleep in the last third of the night. So it is much harder to get them settled again, from around 3am in the morning until getting-up time."
Dean says the problem sometimes doesn't present itself for a few months down the line.
"It comes down to problems with self-settling. If you can work out what the prop is, and then focus on the bedtime to start with, to get them down awake, the rest of the night tends to follow on from that," she says.
She has devised a series of tips.
She says that although a 'soothology' routine is all about establishing a good bedtime routine, daytime naps are important too. Lunchtime naps can help babies feel rested, ready and raring to enjoy the afternoon.
Dean says to try as much as possible to put the baby to sleep, be it naps or at night, in the same place -- ideally the nursery. Keep the nursery at a consistent temperature. Babies can often get quite hot, but it's important they don't get too cold either.
Ensure the nursery is a soothing, happy place, with a mobile above the cot and an age-appropriate comforter. Black-out curtains can also help.
Soothing is also important -- don't do anything with the baby that will stimulate them for an hour or so before bed. This will ensure they are calm and relaxed.
The final tip is to make sure that baby is wearing a super-absorbent nappy, because a baby can wee up to 12 times a night.
People resort to a variety of different measures in a bid to get their children to sleep.
One Australian study found that parents stayed with their children, while others used drives in the car, the television and even the sound of running water.