As the title says. I am planning to take a year out after my BSc to have a second child. I would officialy graduate in July 2015 and will start to apply from September 2015 for 2016 start.
Do you think it will a problem? Will supervisors question my year out as I will not be at work?
Will they be less likely to choose me because I will have 2 children?
Thanks:)

I really cannot see how this could have any bearing on your application whatsoever.

The most important things are:

1. The quality of your research proposal.
2. Whether the institution think they have the right supervision available for you or not.
3. The quality of your references.
4. Your grades.

They can't discriminate on the grounds of you having children.

There was a 21-year gap between my BSc and my PhD (not child-related) and I wasn't asked to account for all that time! As Huxley said, it's the quality of your application, your skills, how well your research ideas fit with the department and so on that they will consider.

I don't see any reason why this should be a barrier. The only thing they might enquire about (though I'm not sure if they can) is whether you would need any accommodations in terms of managing childcare.

It does really depend on your choice of project though. Something like cell biology where you need to tend to your experiments very frequently at particularly times might afford you less flexibility than an analysis based project. But that depends on your personal arrangements as to whether or not this would be a problem.

As much as anticipating what they might ask you, I would make sure I asked them plenty of questions too. I have no experience of this myself but I imagine that there is variation between departments/institutions as to how hard/easy it is to balance childcare and PhD work.

Thanks guys:)
I am in science so I supppose I am worried they will look at me like I am out of date.

Regards childcare, my husband is really supportive and is happy to stay home with kids when ill if he needs to. I mean I will also stay occasionaly but it will be shared.
But with the one we have now it isnt a problem really, not ill for about 2 years now!

They cant but they can make up other reasons:(
I am just worried if it could affect them or not.

I don't think at this stage in your career you need to worry too much about being 'out of date' - it's more of a challenge at more senior grades.

If you're concerned about losing touch with science, there are ways you could keep yourself fresh e.g. try to get hold of latest papers in key journals, or take an online course (e.g. Coursera) in something new to keep your knowledge fresh and developing.

Regarding the childcare, do think carefully about the specifics of a project and how it would affect your time management. It's not just about whether your kid's off sick, it can also be about how often you planned to leave at a certain time, but you can't because the previous person using the equipment has over-run. There is a lot of variation even within a field as to how flexible a given project may be, and it's probably preferable to think about that at the outset, according to yours and your family's needs.

That's not to say that certain types of project are not doable by people with young kids, but they may require a lot more planning to do them, and that is one thing that might come up in interview. But there are other people on here who are better placed to advise on these issues.

Thanks:)
That wont be an issue. I did year long placement where I was working like a PhD student (weekends etc. )
My husband works for NHS and his work is very accommodating. Last year (during the placement) I was dropping my child off and he was picking up so working late was never the issue.

Sounds like an excellent arrangement. Good luck with the applications when the time comes. I think it should be fine.