A man and woman enter a fertility shop. "Yes please how can I help"? We would like to see what we can do about managing our fertility please. Lets see then how much did you want to spend? "Nothing at all if possible but show us the range". Ok, "absolutely no baby and sex galore" is top of the range but pricy and involves hysterectomy. This next option is called " no sex and absolutely no baby" and it does what it says on the tin and counselling may cost a little. Over here we have the pill/potion/injection department and these do cost, and have many unwanted side effects like blood clots and breast cancer but many take the risk. As regards babies yes they do occur at a rate similar to or not quite as good as the next option which is called "natural sex for intelligent self controlled adults". This is free has no side effects and is gaining in popularity. The idea is that you dont have sex when the female is fertile and you can tell this from several signs. It has been used very successfully in poorer countries and studies in several high profile journals published this, but it is ignored by those who want to push pills or implants or IUDs and who think sex is just an impulse and has nothing to do with responsibility and babies. So what will it be then?? We'd like the intelligent one please and so it won't cost anything and has absolutely no side efects and since we just married we would love a large family.

Competing interests: None declared