Breeding from an older mare

Question
I was interested in your thoughts/views about breeding from an older mare. My 15.2hh IDxTB mare is 18 years old she is fit/healthy and still competing SJ and eventing however I have been thinking about breeding from her either this year or next year. She has had one foal before (4 year old filly who is a nice type and just starting her ridden career). She was AI'd before and took first time, her pregnancy was straight forward although she did keep us waiting an extra 4 weeks over her due date! I also didn't ride her through any of her pregnancy as in the early months she appeared quite tired. I am keen to have another foal from her as I am pleased with daughter and she was a good mum. However are the risks of pregnancy significantly increased compared to before?
Your thoughts would be appreciated.
Thank you

Answer
If the mare is healthy then it should be fine to breed her. There are a few things to look out for such as Older mares have about a 30 percent chance of becoming pregnant and need to be bred more then once. They can have poor uterine clearance, anatomical defects involving the reproductive tract, contamination, infection and aged eggs. There can also be poor vulva conformation. as long as you make sure that you have her cultured prior to breeding, that she gets the proper shots and that she is getting a good nutrition feed, then she should not have problems.

Lisa