I have had several (male) friends say that women think a guy carrying a baby is sexy. Plus they reckon it is a really easy way to break the ice and start a conversation.
Being a single dad I think this is an urban myth.
My experience is that strangers will ask if you need help, and when you say you are ok they some times persist. Some even ask if the mother will be away for long. When I have replied that she is not coming back.... ever! They appear shocked. Sometimes its just better to walk away.
But it does not help to meet a date. Mind you I am not in that mindset when I am at the shops.
The greatest sex organ we have is not between our legs; it is between our ears. If a man knows what to SAY to a woman, and knows how to seduce her then that is sexy - right!
The same goes for a woman. A normal woman with a wild mind is much sexier than a size 6 ice queen.