Yes, it is best to give birth while married. If a woman is in a married relationship when she gives birth to a child, then she is provided support by her partner. In addition, the child is provided the support, warmth, and stability of a loving relationship. This will help the child thrive as it grows.
Yes, I believe that it is best to give birth while married, if the husband is able and willing to be a good parent. Two-parent homes usually have better outcomes for children. There are also usually more finances available to raise the child. In most cases, marriage is a better way for a child to grow up.
Personally, I do feel like it creates a better environment for not only the baby but the couple as well if they give birth while married. That way you know both of you are in this relationship for life and are both willing to put in the effort for this child.
Unfortunately, in today's world, finances are one of the most important things when raising a child. Whether you are single or otherwise, you should not want to bring a child into a world of poverty. Being married reduces this risk, but sometimes it doesn't. The most important thing is being able to afford your child completely.
I do not believe it matters if you are married while giving child birth. Marriage is a union completely made up by man and the premise of marriage in America has little to do with faith or love. While I find that children are better off in two parent households I do not believe marriage and birth have much in common.