BABY CARRIER要等到BABY長到兩三個月，脖子有足夠的力氣支撐腦袋的時候才能用。10幾磅的孩子掛在胸前還是很吃力的，容易累得腰疼。孩子再大一些的時候，前置式的基本就很難用了，不僅是因為小孩太重，（記得大多是推薦UP TO ~18LB），還有小孩子的活動和視野受到限製，他自己比較不舒服，也會比較熱。
There are commercial ones available also. The most expensive brand is "Baby Bjorn". The commercial carriers are only recommended for carrying babies up to 20 lbs. It may be uncomfortable for the baby beyond that weight.
We used one until my son was 5 or 6 months and it was very helpful. He even fell asleep in it. We stopped using it not because he was too heavy, but because at that age he became interested in other activities such as learning to crawl.
