Since my daughter Cecily was born nearly a year ago, I had not had a single uninterrupted night's sleep. She howled whenever she was put in her cot and woke at all hours, usually ending up in bed with us, or my husband was relegated to the spare room. This was rapidly taking its toll on all of us, including my four-year-old son Henry, who had never caused problems in the sleep department. The final straw was a stress-related outbreak of acne worse than anything I'd experienced in adolescence.

But in this era of thirty and forty something working parents with more money than energy, help is at hand in the form of a new and booming sleep industry.

Exhaustion finally overcomes any guilt at delegating my motherly duties. I call The Sleep Nanny, a mother of two and a former nanny who has become a specialist sleep consultant, who will stay in your house for two nights, taking over all the wakings, and, ideally, transforming your baby into a model sleeper.

Since she has tended the babies of celebrities and aristocrats I clean and tidy up, scrub the children vigorously and dress them extra nicely. I needn't have worried. The Sleep Nanny exudes calm, kindness and competence. The children instantly take to her and she pitches in as though she's been here all her life.

But why did we ever get to such a state that we needed a sleep nanny? According to Dr Olwen Wilson, a child psychologist, babies are not programmed to sleep like us. While we have roughly one six-hour period of deep sleep and two hours of light sleep, babies naturally dip in and out of sleep twice as fast as we do.

A study in 1994, part of the Avon longitudinal study of pregnancy and childhood, in which researchers surveyed the parents of 640 babies, showed that only 16 per cent of babies slept though the night at six months and, of those, 17 per cent woke more than once a night. By year one, those sleep patterns will be closer to adult ones, but our babies may have learnt bad habits by sleeping with us; being fed four times a night and we may be on our knees with exhaustion.

Over dinner, our sleep nanny goes through her plan. On her advice we are already waking Cecily at 7am and she is consequently going to sleep earlier. The Sleep Nanny suggests waking her for a feed at 10.30pm and tells us that from then until 6.30am is cot time and Cecily will stay there whatever happens. Warning us that there will be some crying, she promises not to leave her to cry on her own. I don't have a magic wand, she warns, but I'll do my best.

That night I skip up the stairs, giddy at the thought of not getting up in the night for the first time in a year. Cecily takes her 10.30pm feed, while barely stirring, and goes back to sleep.

Our Sleep Nanny, I realise, knows her stuff. At 12.30am the crying starts. And continues. I feel sweaty and agitated, but I don't buckle. I'm reluctant to intervene and waste The Nanny's time, not to mention her fee plus agency and travel expenses. So I ignore Cecily's wails, which are losing intensity. An hour-and-a-half later, she is asleep. In her cot. A miracle! In the morning The Sleep Nanny brings our smiling baby in for a morning feed. During the night she actually lay on the floor next to Cecily's cot, patting her while she yelled. She expects Cecily to be sleeping through within a week. My husband and I exchange sceptical raised eyebrows.

The next day is bliss. our sleep nanny plays with the baby and chats to Henry while I drink tea, enjoying the sensation of having had more than five consecutive hours of sleep.

The next night goes even better. This time Cecily bleats for about half an hour, while our sleep nanny sits in a chair beside the cot, not making eye contact but offering the odd pat and squeeze. At 7am Cecily has to be woken. We are astounded. And horrified. Could it really have been this easy all along? Why on earth did we not do this sooner, before things got so bad? The Sleep Nanny urges us not to let her work go to waste. We promise to keep it up and, very sadly, wave her goodbye on Tuesday. We do as she says: patting, no eye contact, Cecily staying in the cot. And it works. By Friday she is sleeping through the night. We are transformed. I have more patience, more confidence, I'm calmer and have better skin.

But if getting a baby to sleep is so simple, why don't we manage to do this without help? This may be because we are the most inexperienced mothers in history. We don't grow up with small siblings to practise on, we don't see babies around us. Often the first baby we ever hold is our own. And we live far from our families so have little support or advice.

Is the rise of sleep coaches another symptom of our increasing dependence on self-styled experts and a loss of confidence in our instincts? Aimee Turner says, "We have lost faith in ourselves as parents and are terrified of giving our children boundaries. She says that having boundaries gives children a deep sense of security." A child that does not have the things in place to allow him to sleep, is ultimately denied the right to refresh himself for the day by sleeping." And as The Sleep Nanny points out: It's easier for me to listen to your baby cry. I'm not her mother. But children do have to learn that night is for sleeping and if it is done properly, with the parent providing regular reassurance, and in the context of a warm and loving family life, there is absolutely no evidence that sleep training causes psychological damage.

And it works. It makes whole families happier, including the children themselves who are often more affectionate, more relaxed and have fewer tantrums.

For me, having someone to do the work of sleep training was like having a fairy godmother. But if you decide to go down this path make sure that you find a sleep coach you like and whose methods you feel comfortable with. Interview her over the phone before you hire her. You do have to be ready to follow through, says our sleep nanny. I need parents to support what I am doing or it really is a waste of everyone's time. I say I am kind but I am firm." As for me, if I have one regret about the whole experience it is only that I didn't do it six months earlier. For the price of a night for two at an overpriced boutique hotel, we have our sleep back. Priceless.