Not my words, that's what the docs say (apparently particularly the case if you have never had children when you get into 40s). I think it's a balancing act. I hate it when people try and scare women into having babies when they're not ready becasue they think they won't be able to have them later in life, but equally women do need to know that fertility halves after the age of 35 and then halves again in your 40s. Many women end up dissapointed and/or spending thousands of pounds on fertility treatments. Govt cut backs mean some areas are saying they will withdraw free IVF cycles too.
Obvioulsy you should use contraception as long as you have periods, as you don't know when menopause will hit, but I think it's more dangerous to reassure women they will be able to get pregnant in their 40s when it may not be the case.
Re the whether you can get pregnant as long as you are having periods qiestion, apparently the ability to become pregnant stops 5-10 years before periods stop.