Figures from the population trends survey published by the Office for National Statistics, show the number of under-16s falling pregnant is at its lowest since 1994.
The figures, from 1999, cover a period before the launch of a controversial £2m government campaign, launched last October, which was aimed at tackling high teenage pregnancy rates.
Through magazine adverts, it advised teenagers to resist peer pressure to have sex.
The Family Planning Association said it hoped the effect of the new measures would be seen in a further drop in figures in coming years.
The UK has one of the highest teenage pregnancy rates in Europe.
Conception rates fell in the early 1990s but rose between 1995 and 1998.
The new figures show they have fallen from 64.9 per 1,000 women in 1998 to 62.8 per 1,000 in 1999.
Brook advisory service said the new figures, were a welcome first step.
Chief executive Jan Barlow, said: "These figures show how important positive steps at a local level can be in tackling the problem."
Fall in young teenage pregnancies
The overall number of pregnancies in England and Wales fell by 3% between 1998 and 1999, the figures show.
More young teenagers seem to have heard the public health messages, with 4% fewer girls under 18, and 7% fewer girls under 16, becoming pregnant.
The figures also reinforce the perception that women are building up a career before having children later in life.
Three per cent fewer women under 30 are conceiving and 2% more women over 40.
Marriage is also being delayed until later in life, with men tying the knot at an average age of 30.1, up from 29.8 in 1998.
Women are marrying at around 28, compared with 27.7 in 1998.
Among girls under 18, 43.1% had abortions.
Jan Barlow added: "Much more still needs to be done to equip young people with the skills they need to protect themselves from sexually transmitted infections and unplanned pregnancy."
A spokeswoman for the Family Planning Association told BBC News Online said the high profile of teenage pregnancies could have had an impact on the figures: "There's been so much dialogue that once it's brought out in the open and teenagers start to hear it, the message starts to get through."
Anne Weyman, chief executive of the FPA said the ONS figures were welcome, but that annual rates had fluctuated over 30 years.
"Most teenage pregnancies are unplanned, yet young people still do not have reliable access to the most effective and appropriate information, skills and services to enable them to access sexual health and contraceptive advice."
But she added: "We are optimistic that the work now under way at both local and national levels will ensure that the downward trend will continue over the coming years."
Yvette Cooper, public health minister, said: "These figures are encouraging and suggest that we may be starting to see a reduction in teenage pregnancies.
"However, teenage pregnancies remain far too high. That is why we have begun a nationwide strategy to tackle teenage pregnancies and why we are introducing further measures this year to bring teenage pregnancy rates down.
"It is vital that the strategy is as much about teenage boys as well as teenage girls - after all, they are half the problem and half the solution too."