How long should a contraction stress test typically last to ensure accurate results?

A contraction stress test is designed to assess how well the fetal heart responds to contractions of the uterus, which can be indicative of fetal well-being. To ensure accurate results, the test typically lasts between 10 to 20 minutes. This duration allows enough time to observe the fetal heart rate's response to several contractions, providing a clearer picture of how the fetus reacts under the stress of uterine contractions.

During this time frame, the medical team can monitor for adequate uteroplacental blood flow and verify if the presence of contractions leads to any abnormal fetal heart rate patterns. The extended time frame beyond 20 minutes is generally unnecessary and could lead to fatigue for the mother or false positives. Therefore, conducting the test for 10 to 20 minutes strikes a balance between obtaining enough data and ensuring the comfort and safety of the patient.