When i was pregnant with my 1st son, he was 9lb 4oz born and was a horrible birth leading to forceps and blood transfusion. will be second be as big?

Possible: Big babies may be due to pregnancy diabetes or genetics. If you had a very delivery you may want to consider a csection.

Hard to predict: Large babies tend to recur. You are at higher risk for having a larger baby given your history. With that said, there is no guarantee that you will have another 9 lb baby. In addition, there are many other factors that decide a baby's size (i.e. Maternal weight, diabetes, gestational age at time of delivery, etc).