In 2004, 434 girls under the age of sexual consent fell pregnant, compared with 537 in 1999. But conception rates among girls aged 13-17 were still higher in five Welsh counties than anywhere over the border that year.
The number of pregnancies among women under 20 is also on the increase, and abortions have gone up in the under-18 age group since 1999.
Torfaen had the highest recorded conception levels at a staggering 66.9 per 1,000 girls. But Merthyr Tydfil, Wrexham, Rhondda Cynon Taf and Caerphilly also had higher conception rates than the North-east of England - the highest recorded English region.
The Welsh average for teenage conceptions in 2004 was 45.1 per 1,000 girls, compared with 41.5 in England. That works out at 2,605 pregnancies in Wales.
Monmouthshire had the lowest number of teenage pregnancies, at a rate of 21.6 girls per 1,000. In England, conception rates ranged from 50.6 per 1000 in the North-east to 33.5 in the South-east.
In 2004, the percentage of under-age pregnancies terminated in Wales was 49 per cent. Swansea has had the most success at reducing teenage pregnancy rates since 1999, athough conceptions among 15-17s were up in 2004.
Mark Campion, Swansea council's personal and social education adviser, said there had been "no single magic wand" in achieving the 25 per cent reduction.
"Over the past few years schools have been constantly improving their PSE provision," he said.
"There have also been a lot of agencies working on the problem, including schools, Swansea NHS Trust, the council, the National Public Health Service for Wales, charitable groups and partnership projects."
Swansea's rates of conception have gone down from 41.5 per 1,000 in 1999 to just below the Welsh average in 2004. But Wales still has one of the highest rates of teenage conceptions in Europe.