I am quite shocked at the attitudes on this thread. Leaving aside the consideration about a chid knowing its heritage -- and there is some validity to that, though nothing that I don't think can't be overcome through open communication with the child.
The default assumption from many people is that a child is intrinsically disadvantaged by not growing up in a nuclear family and I find that genuinely shocking.
Go onto the relationships board and you will find, on any given day, threads from dozens of women who are plainly far, far better off bringing their kids up alone and are wrestling with the decision as to whether to "break up the family" (they never are, it is invariably the dad who is doing this). For a number of reasons ranging from infidelity to abuse to substance abuse problems on behalf of the father. Most of these women come back on months/years later to say, basically, thank God I LTB, my kids are more stable, happier, thriving without the toxic influence of the man who was the source of the problem.
Obviously a happy, stable, two parent household is the optimal way to bring children up and obviously you should think very carefully if you want to embark on a pregnancy without a father. But there seems to be an assumption on this thread that guaranteeing a dual-parent family is the lion's share of bringing up kids properly. And that leads to all sorts of self destructive assumptions, around the idea that its basically the woman's job not to "break up the family", and therefore to tolerate all manner of disrespect and abuse in order to attain the holy grail of a nuclear family.
There are millions of single parent households in this country where women it usually is women are doing far, far better jobs than they were wrestling with a declining, stifling or abusive marriage. Many of these women strive to maintain decent relationships with the father post split, some choose not to. I know of so many such families and without exception they are all doing better and the kids are happier than they would have been without the father involved.
I have almost zero support and am doing, if I say so myself, a pretty good job of raising my DD on my own basically because her father was flaky and abusive and I took the decision for both of us not to have to spend the rest of or lives having his behaviour overshadow our self-confidence and our autonomy. And I don't regret it for a second. I am 100% sure my DD is happier than she would have been had I remained with her dad.
I'm not denying that these are careful decisions which should be embarked upon with care and planning. But some of you need to have a look at your attitudes and your attitudes to parenting and have a word with yourselves. One strong, stable and loving parent is far far better for children than a dysfunctional pairing. And a far greater number of marriages are dysfunctional than many people will allow themselves to admit.
Rant over.