Which of the following is a risk factor for a high-risk pregnancy?

Multiple gestations is indeed recognized as a significant risk factor for high-risk pregnancies. When a woman is pregnant with more than one fetus, such as twins or triplets, the risks for complications substantially increase. These complications can include preterm labor, gestational diabetes, high blood pressure, and increased likelihood of cesarean delivery, among others. The physiological demands on the mother's body are greater, which can lead to a range of health issues for both the mother and the babies.

In contrast, being aged 25 to 30 with no health issues generally signifies a lower risk status, as this age range is typically associated with fewer complications. Having a healthy BMI is also associated with lower risks during pregnancy, as it often reflects better overall health. Furthermore, being physically active during pregnancy is generally encouraged, as it can lead to better outcomes for both the mother and baby, contributing to a healthier pregnancy experience. Thus, none of these factors contribute as significantly to risk compared to having multiple gestations.