Well I can add to that theory too - When I had my eldest I drank no caffeine what so ever. I had the odd bit of chocolate but that was it. With my eldest I'd just decided to go on a health kick which meant banishing all caffeine. This time I've had loads of caffeine - I mean at the time of conception my caffeine intake was through the roof! I was taking orlistat and they made me exhausted, so I used caffeine to keep awake during the day - dont know gender yet.