The provision of IVF to women on the NHS is subject to significant regional variations in how many cycles of treatment are available, and to which age group.
A study by Conservative MP Grant Shapps discovered that eight out of 10 primary care trusts (PCTs) admit failing to follow NHS guidelines introduced in 2004, which suggest women should be given three free cycles.
The study is based on an 80% response rate from PCTs and underlines some significant regional variations.
For instance, in the East Midlands, every trust offers one full cycle of treatment but in the South East 41% do not offer IVF to any woman aged 23 to 39.
Also in the East Midlands, no PCT would offer treatment to couples in which one partner already has a child but 70% would in the North East.
Two of the trusts refused any woman IVF in the previous two years while one in eight are failing to comply with guidelines on a woman's age.
In its 2004 guidance, the National Institute for Health and Clinical Excellence (NICE) said the NHS should fund three cycles of IVF for women under 40. But the latest evidence shows most PCTs are still failing to offer three cycles.