Which of the following conditions is considered a risk during pregnancy?

Spontaneous abortion, also known as miscarriage, is regarded as a risk during pregnancy because it represents the unexpected loss of the fetus before the 20th week of gestation. This condition can happen due to various factors, including genetic abnormalities, hormonal issues, or problems with the uterus. The risk of miscarriage is a significant concern for expectant parents and healthcare providers, as it can be emotionally distressing and may indicate potential complications in a future pregnancy.

In contrast, morning sickness, back pain, and stretch marks are common experiences during pregnancy that, while they can be uncomfortable, do not pose significant risks to the fetus or the pregnancy overall. Morning sickness is a frequent symptom experienced by many pregnant individuals, typically involving nausea and vomiting. Back pain is also a prevalent complaint, often resulting from weight gain and changes in posture. Stretch marks are a normal outcome of skin stretching during pregnancy and are not indicative of any health issues.