The majority of pregnancies are considered low risk. This means that there are no complications, and that there are no known factors in the health of the mother or the baby that places the pregnancy at increased risk of complications.
Certain risk factors may influence additional assesments and interventions, and a closer following of the patient during her pregnancy. Having a High Risk Pregnancy, does not mean that you or your baby will have problems. It means that your doctor needs to watch you closely in order to keep you healthy and your pregnancy without complications.
If you have a health problem such as Diabetes, Cancer, Epilepsy or High Blood Pressure, or have had previous miscarriages, preterm labor in previous pregnancies, multiple pregnancy, you will be considered high risk.
Please be sure to mention any previous health issues and complications to your doctor.
High Blood Pressure During Pregnancy
http://www.acog.org/~/media/For%20Patients/faq034.pdf?dmc=1&ts=20130218T2012256612