Natalie’s grandmother is in no doubt about how it could have turned out. At 15 years old, Natalie was drinking heavily - a crate of beer plus a bottle of vodka was her typical daily intake - on top of speed, cocaine, ecstasy and cannabis. Her behaviour was alarming her family.

“She asked me the other day what I thought would have happened to me,” says Natalie. “I said I didn’t know, but she said she knew. She said I would have been dead by now.”

What saved Natalie was getting pregnant. When she found out, she stopped drinking alcohol and taking drugs. Now 17 and the mother of a 15-month-old girl, she says her daughter’s arrival transformed her.

“I was feeling quite down before. I didn’t really enjoy my life, I just did it. Now I love my life. I’m not a little chav any more,” Natalie says.

It’s not quite the conventional view of early motherhood. According to the Government, teenage pregnancy is a serious social problem, a pernicious con-tagion spelling disaster for everyone involved: the girl, the child and society as a whole.

The government’s Teenage Pregnancy Strategy, introduced in 1999, aims to halve the under-18 conception rate by 2010. After nine years and pound;150 million, progress seems to have stalled with a fall of just 13 per cent and there seems little prospect of reaching the target.

But does having a baby always ruin teenagers’ lives? Could it in fact be a reasonable option for some girls, for whom the alternatives are unappealing at best? Natalie could be an exception, but the positive effects could also be more widespread, providing meaning and focus for otherwise directionless lives.

Like many of the other two dozen girls at Hull’s Schoolgirl Mums’ Unit, Natalie rarely went to school. When she fell pregnant at 15, having suffered a miscarriage only a month earlier, her reaction was far from despondent. “I was really excited, I couldn’t wait,” Natalie says. “It wasn’t planned, but I did want my baby.”

Having had no ambition in her pre-motherhood days, she confesses, Natalie now wants to train as a teaching assistant. She has taken her GCSEs and her relationships with her family have improved dramatically.

This kind of response is common in many at the unit, says Julie Stamper, its headteacher. She says it is only when they become pregnant that many realise they have a reason to have aspirations.

“They want to have a career, they want to do right by their children,” she says. “A lot of them would never have had that drive if they had never had their babies.”

Hull has one of the highest teenage pregnancy rates in the country, with 69.8 conceptions per 1,000 girls aged 15 to 17, compared with 40.9 in England and Wales as a whole. As such, Hull is at the sharp end of the government’s attempt to reduce teenage pregnancy. The picture varies across the country, with some areas, such as York, Stockton and Norfolk, showing an increase.

One of the largest falls, of 37 per cent, has been recorded in South Tyneside. David Messenger, a sexual health trainer at the local primary care trust, acknowledges that raising aspirations is crucial in persuading young girls to delay motherhood.

“When you look at the alternatives and the background of some of these girls, pregnancy can be seen as a rational choice,” Mr Messenger says.

“Sometimes if school is not for you, to be a parent is not an unhealthy aspiration.”

South Tyneside’s approach has combined sex education, making contraception available, and support for younger mums. The trust also works with young mums to develop post-birth contraceptive plans. One in five teenage pregnancies in South Tyneside is the mother’s second. “We support them through the pregnancy and give them a choice of whether they want another child,” says Mr Messenger.

Figures on teenage con-ceptions lend support to the theory that aspiration is the key factor. Areas with the highest numbers of under-18 conceptions tend to be those with the greatest levels of deprivation. Just as clear is the correlation between de-privation and abortion rates: as a rule of thumb, the more deprived an area, the lower its abortion rate.

Ann Furedi, chief executive of the British Pregnancy Advisory Service (BPAS), the UK’s largest independent abortion provider, says that girls who have expectations of going on to university and forging a career are more likely to view pregnancy as a disaster.

“We know that young girls from middle-class backgrounds are less likely to have a teenage pregnancy, and if they do, they are far more likely to opt for abortion,” she says.

The Teenage Pregnancy Strategy sets much store by making contraception widely available and improving sex and relationship education, but Ms Furedi questions whether these will have much impact. She says most young people know that penetrative sex can lead to pregnancy. The problem is not that contraception is not available, it is that teenagers don’t always use it, particularly if they are ambivalent about the consequences. The over- riding factor is poverty. “The best form of birth control is ambition,” she says. “If people believe having a baby is going to be a disaster in their life, they are motivated to use contraception.”

But Simon Blake, chief executive of Brook, a charity that offers advice on sexual health, believes there is still an alarming knowledge gap. Mr Blake, a member of an independent group advising the Government on its teenage pregnancy strategy, says he recognises the role played by aspirations, but sex education and contraception are crucial in breaking the cycle whereby children of teenage parents are more likely to become teenage parents themselves.

“It’s not all about knowledge, but it’s not all about choice either,” he says. “Lots of young people are not particularly fussed about getting pregnant. It’s not a choice, it just happens. We need to break the cycle of poverty and exclusion, and contraception and sex and relationship education is incredibly important in that.”

The conventional justification for trying to reduce teenage conceptions rests on evidence suggesting that the prospects for teenage parents are worse than for older mothers. A UNICEF report in 2003 claimed that teenage mothers were more likely to drop out of school, have low or no qualifications, to be unemployed or low paid, to become involved in crime and to use drugs and alcohol, among other social ills.

But recent research casts doubt on these findings. While teenage mothers may fare worse than girls who delay motherhood, the differences almost disappear when comparing girls of similar backgrounds. Studies in the US and the UK have found that by the age of 30, teenage birth had little effect on qualifications, employment or earnings.

In fact, a study carried out for the Teenage Pregnancy Unit in 2004 found that, “the negative consequences of having a teen-birth for the mother are not as wide-ranging as earlier research suggested”. The poorer outcomes are more the result of her social and economic starting point. The principal disadvantage for teenage mothers, researchers found, was that they struggled to find suitable partners, being more likely to enter a relationship with a man who is poorly qualified and unemployed.

T he study did find, however, that outcomes for the children of teenage mothers were worse: lower educational attainment, greater risk of unemployment, lower income and a higher risk of becoming a teenage parent themselves, although this was also the case for mothers who gave birth in their early 20s.

Far from the consequences not being disastrous, there is evidence that early motherhood can be beneficial. Simon Duncan, professor of comparative social policy at Bradford University, cites research showing that motherhood could spur some girls into education and employment, and that for some young women, motherhood “increased their self-esteem and enhanced their lives”.

Professor Duncan contrasts the approved “slow lane” to adulthood, of a career then parenthood, with the stigmatised “fast lane” of young motherhood. But while the fast lane may be frowned upon by middle-class policymakers, it can be a rational choice for people in particular economic, social and family circumstances. “When you go through all the evidence, you begin to wonder what all the fuss is about. If it is a social issue it is a minor one,” he says.

“From an economic point of view, you could even say `let’s encourage teenage pregnancy’, as it is a positive turning point for many young women in otherwise disadvantaged andor alienated circumstances.”

Lisa Arai takes this further and suggests that for some young women, early childbearing represents an alternative vocation. Dr Arai, a lecturer in children and young people at the Open University, conducted a series of interviews with women who had their first child before 20 to research the attitudes and expectations of young mothers. She found that they fell into two groups: those who had experienced severe adversity in early life, and those who came from less fraught and usually loving backgrounds.

For the first group, childbearing was often a way to be loved. For the second, motherhood was a more appealing option than low academic achievement and poorly paid jobs.

Dr Arai blames middle-class myopia for the failure to understand the full implications of motherhood. “It has benefits that policymakers don’t see, but young women are aware of them,” she says. “In many geographic and social settings, teenage pregnancy is in some senses a desirable outcome, and even when it isn’t desired, it isn’t a terrible thing.”

These findings are supported by a study carried out by Lester Coleman at the Trust for the Study of Adolescence into “planned” teenage pregnancy. He found that young people saw parenthood as an opportunity to change their lives for the better.

“There were some quite rational appraisals of why they became pregnant and how it had improved their lives, giving them confidence and self-esteem. It also helped re-integrate them into their families,” he says.

If the effects of teenage pregnancy are not that disastrous, why has it been elevated into a key issue, particularly when rates are lower now than at any time in the past 50 years (see graph)? Professor Duncan suggests that it may be connected with a fear of teenage sexuality, sometimes seen as responsible for a supposed breakdown in family values. There may be an inability to understand the ambivalence towards parenthood of some teenagers: when choice becomes so important, failure to choose can be disconcerting.

But turning it into a social problem has attached a stigma to teenage motherhood, making it shorthand for deprivation. Attaching a figure to the cost of under-18 conceptions, estimated at Pounds 63 million a year, makes it also an economic problem, even though no one tots up the cost of becoming a mother at 40-plus, in dealing with the poorer health outcomes for mother and child.

Mel, a student at Hull’s Schoolgirl Mum’s Unit, felt the rough end of this stigma a few days ago, when she was chased down the street by an old man waving a stick. “He was shouting: `Pussy footing young mums, always fucking about’. I was really scared,” says Mel, 17, the mother of a five- month-old boy.

Jan Macvarish, a re-searcher into teenage parenthood based at Kent University’s centre for health service studies, suggests this hostility is a natural consequence of demonising young mums.

“If you assume teenage girls got pregnant because they are inherently incompetent, you assume they cannot look after their babies either,” she says.

Ms Macvarish regards the teenage pregnancy strategy as unnecessary, creating a problem where it does not really exist. “It is up to people when they have their babies, why should the state intervene?” she says. It also ignores the fact that most teenage conceptions are to girls aged 16 to 19, with pregnant 13-year-olds the exception.

J ohn Coleman, an Oxford University psychologist and deputy chairman of the government’s advisory group on teenage pregnancy, argues there is a place for a pregnancy strategy, although he says it is particularly relevant for under-16s, who make up the minority of teenage conceptions.

Dr Coleman acknowledges that pregnancy can be a positive option for some, but suggests this is only when they have good childcare, a supportive family and decent housing.

“There are an awful lot of disadvantages associated with teenage pregnancy,” he says. “That is not to say that in some circumstances it may not be the right option and a positive life choice, but you only have to see young mothers in terrible housing to know how difficult it can be.

“I have never been one to say teenage parenthood is a bad thing, I don’t believe that is right, but taking all the circumstances into account it is better to delay if you possibly can.”

Childcare is one of the areas where units such as the one in Hull can help. The nursery, with places for up to 28 children, is on the ground floor of the former Fisherman’s School that has housed the unit for eight years, giving the mums in the classrooms easy access to their children for feeding.

The unit also runs health, midwife, careers and sexual health clinics, as well as helping the girls to stay in education.

Denise, 15 years old and 29 weeks pregnant, admits to having hardly gone to school at all for the past two years, but now happily turns up at the unit every day. “I have changed in myself,” she says. “I just did what I wanted before, but I want to go somewhere in life now.”

Denise says she is determined not to repeat her mistakes. “I’ve had people shout stuff at me and people stare at me, but I’m proud of having my daughter, I’m proud of who I am today,” she says.

While no one would argue that teenage parenthood is easy, perhaps it’s time to rethink the idea that having children ruins young girls’ lives

Rebecca’s story

Rebecca Whorton became pregnant two months before her 14th birthday. Now the mother of a 12-year-old girl, Rebecca works in the housing department of Rotherham Borough Council.

“When I found out I was pregnant I was terrified. I didn’t know what to do and I didn’t tell anyone until I was seven months.

“I’d always got good school reports, but then I fell in with the wrong crowd and before I got pregnant I was failing at school. The pregnancy is what gee’d me up, it saved me. I had something to work for. I left school and went to the Rowan Centre (a Barnardo’s project in Rotherham). I’d been selfish, but suddenly everything wasn’t about me, it was about us, and I knew if I didn’t get an education and didn’t start succeeding I wasn’t going to have much to offer my baby.

“I don’t know where I would have ended up if I hadn’t got pregnant. I was with a lot of bad people and I think I would probably have been a nothing, a nobody.

“At first it was a shock, but then it was an inspiration to do something with my life.”

*Some names have been changed