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In general, a pregnancy may be considered high risk if the pregnant woman:
- is 35 years old or older
- is 15 years old or younger
- is underweight or overweight prior to becoming pregnant
- is pregnant with more than one fetus
- has gestational diabetes
- has gone into premature labor
- has had a premature baby
- has had a baby with a birth defect, especially heart or genetic problems
- has high blood pressure, heart disease, diabetes, lupus, asthma, a seizure disorder, or another longstanding medical problem.
source: http://kidshealth.org/parent/pregnancy/pregnancy/high_risk.html
