Depending on the sites you are linking to, having more links in your campaign may not be a factor when delivering your message. If you are linking to a site that has its domain blacklisted, this could increase the likelihood that your campaign is filtered when your message is examined by a spam filter.
It may be more likely that the text used to describe a link could cause the message to be filtered, rather than the link itself. It is recommended that you check your message content using a spam checking tool before you send to help minimize this risk.