What factors contribute to a high-risk pregnancy?

High-risk pregnancies are characterized by factors that can compromise the health of the mother or the developing fetus. Maternal age is a critical factor; both younger (teenage) and older (advanced maternal age) mothers can experience complications. Pre-existing health conditions, such as diabetes, hypertension, or heart disease, can also increase risks during pregnancy, as they may affect maternal health and fetal development. Additionally, multiple pregnancies (such as twins or triplets) present unique challenges and are associated with a higher incidence of complications like preterm labor and gestational diabetes.

In contrast, high levels of physical activity and maintaining a healthy diet are generally associated with better pregnancy outcomes and do not contribute to high-risk categorization. Similarly, a family history of low pregnancy weight alone does not necessarily indicate a high-risk pregnancy unless it is accompanied by other complicating factors. Lastly, having previous term deliveries and controlled medical conditions typically suggests that a woman has had successful outcomes in the past, which helps to categorize her as lower risk in her current pregnancy. Thus, the correct answer accurately reflects multiple significant risk factors that could lead to complications in pregnancy.