Career v/s first child-what will you go stand for?

Today's working women usually delay the birth of their first child. The reason they justify is that their career will get affected and hence plan for their first baby when they reach a specific preferred stature in their work career usually achievable post 10 years of their work career i.e in the late 30s of their lives.
Though today, there is medical assistance available to sustain a late pregnancy, the same is restrcied to a specific few developed countries and the chances of success are usually unpredictable."What is the right age to have a baby" or is it more relevant to ask "when is the right tme to have a baby". Should career be a deciding factor or circumstances should guide your decision? I personally feel that career shouldnt be a factor to influence your decision. If you are in your late 20s just started wih work but doing good in your respective career, then i dont think that a baby coming your way will hamper your career growth in any way. Career and family should go hand in hand and i am sure dont pose a threat to each other.
i think that a baby in your early 20s will actually help you concentrate more on your career when you require very high level of attention as you progress in your career (post 30)Also, pregnancy is your 20s is definitley going to be less complicated a agianst your 30s.

Lastly if spending more enjoyable years with your child is possbile then why should we limit that longevity and curb it down with lesser number of years only to justify a few manageable issues?

Looking forward for your comments.