is it true that some food items lead to miscarriages if consumed in early days of pregnancy?

I believe so! Caffeine increases the risk of miscarriage and low birth rate, but this is usually when caffeine is taken in large amounts. 200mg/daily is the standard limit. Some doctors advise steering clear anyway just to be safe, but it's one of those things where you don't have to beat yourself up with guilt if you slip every occasionally. :)