Does being pregnant/having dependants effect how much you can borrow?

Hi,

We are currently hoping to start a family and also hoping to buy within the next year. The mortgage calculators I've look at all want to know whether we have dependants (we don't at present).

I was wondering if anyone knew what effect (if any) this will have on how much we can borrow?

Will being pregnant effect an offer also? (I'm the higher earner and more likely to work full time after the baby comes with DH possibly going part time but we're not sure yet).

Thanks in advance :)