I read all about it but as I was having enough worries about whether everything would be ok, mainly because I chose to carry on feeding raw throughout her pregnancy I decided against using any medication in Penny's pregnancy. We were lucky because she whelped 11 pups without the injection all of which ranged weight wise between 7-10oz. we did loose 2 pups during whelping, but the remaining 9 were very healthy.
I would not rule it out however in the future.