Once the baby is born, you'll get access to all the benefits. Go to the forums on moneysavingexpert.com or entitledto.co.uk and watch the $$$ roll in once the sprog arrives.
This is also not true
I have multiple employees who have new borns, both low to middle earners and they can hardly afford to live with both working, as you have to pay nursery fees then.
If the mum doesn't work then they have to live on one wage, which if you are earning say, £18 - £20k means you aren't eligible for much and isn't enough to support a family easily
(Edit : Actually I dont think this tapers, it's either on or off and the threshold is £50k income whereas previously it was universal)