Actually, large families with "stair-step" kids have an advantage. There is more "bonding" and love to go around.
Catholic teaching on this issue is logical. God is the author of life.
"There is another reason why contraception actually leads to more abortions. There is an underlying link, or mentality, between the two. This mentality views human life as something that is not always welcome and, when unwelcome, can be disposed of".
http://nccbuscc.org/prolife/programs/rlp//Schu05.shtml
My exhusband came from a large Catholic family, and, while there were pockets of bonding - depending upon the ages - the older ones did not bond well with the younger ones, and his poor mother was overwhelmed. So, I talk from my own experiences. There is also a lot of jealousy to go around. I saw it all.