Why such a downer on teenage pregnancy?

By Finlo Rohrer BBC News Magazine
News that the daughter of the vice-presidential candidate Sarah Palin is expecting a child at 17 has again focused the spotlight on teenage pregnancy. But why do we have such a problem with it?
A teenager expecting a baby is a bad thing. Or so you would believe if you ever read the news.
It is proclaimed that the UK's rate of pregnancies in females aged 15-19 makes it the "worst" in Europe.
Teenage pregnancies are rising; so are drunkenness, sexual offences and crimes of sadism
Sir Keith Joseph, 1974
This is certainly the government's view. The stated goal of its Teenage Pregnancy Strategy is to "halve the under-18 conception rate by 2010, and establish a firm downward trend in the under-16 rate".
With under-16s it's easy to see the reasoning - the age of consent is 16, compulsory schooling runs until 16. But for those over the age of 16, but under the age of 18, or even 20, is it still a social ill?
The first curious thing about the issue of teenage pregnancy is that many people do not have a handle on the numbers.
Stats confusion
"People massively overestimate the numbers of people who get pregnant when they are very young. When people believe it is a bigger problem than it is then their response will be more polemical or however you want to describe it," says Simon Blake, chief executive of Brook, a charity which offers young people sexual health advice.

Kizzy, who allowed BBC cameras to follow her pregnancy aged 13
Victoria Gillick, a "pro-life pregnancy counsellor" who found fame in the 1980s while fighting for the right to be told if her teenage daughter was prescribed the Pill, often asks people how many girls under the age of 16 get pregnant every year. She is told figures that are dramatically in excess of the real stats.
"In only one year, 1990, has it ever reached 1%," she tells them.
Many people might be under the impression that teenage pregnancies are rocketing. But over the past 10 years they have been falling in England. In 1998, the figure was 46.6 conceptions per thousand girls aged 15-17. In 2006 it was 40.4.
For 13-15 year olds, numbers are also falling. In 1998, there were 8.8 conceptions per thousand girls. In 2006, there were 7.7.
But it is still a pervasive issue in the media and in popular culture, with representations as varied as the positive spin of the recent movie Juno, to the now notorious Vicky Pollard of Little Britain.

Juno trailer