How old is too old to adopt a newborn

I was 38 1/2 and my husband 44 1/2 when we adopted our daughter 18 months ago. We are kind of in the same boat you are in terms of thinking of a second adoption. We need to save money and be in a bigger house so that will put us at 42/48 if we try again. I think that if you have the energy-go for it. I don't think birthparents are as concerned with age as your love for the child. I would think to a lot of bmoms a big family would be a plus also.