If the intent is to maximise reproductive capability, then really its the men who should be left behind. Their... part of the reproductive process can simply be transported along frozen for later use.
Though I'm not sure you want to encourage fast population growth. Children are a strain on scarce resources. You might actually wish to discourage reproduction in the early years of settlement.
As I posited in another thread, if the intent of the expedition is maximum reproductive efficiency, then you either dump the men, or just dump people entirely and send along a bunch of prepackaged genetic material to be incubated in artificial wombs, with either a small support staff or an EDI-style AI with a bunch of robotic avatars to provide care and protection.
Thankfully, it appears that 'maximum reproductive efficiency' is not the overriding goal of the expedition, so we'll probably end up with roughly the same population distribution as each species had in the Milky Way.