Hi, and thanks for your question. It is beyond the scope of this site to explore this concern in depth with you and I would suggest you talk with your doctor or a midwife about your concerns.  More women are now starting their families after age 35.
You might find the following sites useful for a medical perspective on the risks.
The Society of Obstetricians and Gynaecologists of Canada has this to say about having babies after 35 years of age:
http://sogc.org/publications/age-and-fertility/
British Columbia’s Health Link: Pregnancy after age 35
http://www.healthlinkbc.ca/healthtopics/content.asp?hwid=tn10068
and from the US Congress of Obstetricians and Gynecologists:
http://www.acog.org/Patients/FAQs/Having-a-Baby-After-Age-35
Hope this helps. Health Nurse