I wouldn't know - are single women with children the only type of single women you know?
Sounds like - instead of making this about your preference to date a woman who doesn't have kids (because, though I've been that single mom, I really don't blame you) . . . it should not be hard to find, though. So perhaps how you're going about meeting new people is the issue.
Maybe you need to step away from your routine (however it is you expect to possibly meet someone) and set about things differently in regard to relationships in general.
I will say a few things, though, on the general topic:
1) Baby's-father may or may not be a concern. If you're interested enough in that general issue - you could ask. I was divorced and didn't see my ex but a few times while I was single. He was rarely around, not a factor in anything at all - ever. No contact, no phone calls, nothing. Only when I married my now husband years later did my husband insist on getting any sort of child support from him . . . then he was involved for a while - but still, never in person. (Aka: I didn't even want to get involved with my children's bio-father)
2) If you meet the perfect woman and find she has a child - how much will that affect things? So many elements from why she's single (maybe he died and she's living on his life insurance? - or perhaps it was a one-night stand. Maybe their marriage ended amicably and they get along just fine. Maybe the kid is much older.) In my experience: the reason for being a single mom mattered a lot. I was single because my ex husband became a drug addict and I took the kids and left him.
3) For 2 years I dated a guy and in the beginning of our relationship, before he even asked me out, he brought up his interest to be involved with me, and shared with me his concerns about why I was single, how much my ex might become involved, and what I wanted out of a relationship. I did NOT want a father - I didn't want a boyfriend involved with the kids. I wanted a relationship that was separate from my life so I could see to my own emotional and personal needs and NOT become concerned with things getting heavier. I didn't want to face marriage again, or a tense and serious crazy relationship. It was only quite some time later that he even met the kids.