Although most infertile couples should now be able to get one course of free treatment on the NHS, the chances of conceiving and going on to have a baby vary enormously between clinics around the UK, according to a new guide.

The Human Fertilisation and Embryology Authority, which regulates the clinics, effectively encouraged couples to shop around yesterday. Although it does not give star ratings to indicate which clinics have better live birth rates than others, it offers a detailed breakdown of the success rates and the waiting times for every clinic in the UK.

It reveals that the Assisted Reproduction and Gynaecology Centre in London has the highest success rate among women under 35. Nearly two-thirds (59%) had a baby, using fresh - not frozen - eggs. Not far behind was the Nuffield hospital, Woking, with 49% and the Centre for Assisted Reproduction in Gateshead with 43%. But the London clinic has a higher rate of twin pregnancies in this age group (33%) and 3% of the births were triplets.

Some clinics only treat younger women, which will make them appear more successful. The chances of becoming pregnant drop dramatically with age. National figures for the average success rate are 27.6% for women under 35, 22.3% for those aged 35 to 37, 18.3% for women aged 38 to 39 and 10% for women aged 40 to 42.

Waiting times for infertile couples on the NHS do not seem to have improved, in spite of the recommendation to all primary care trusts that every infertile woman under 39 should have at least one course of treatment paid for.