Which condition would likely lead to postponing a contraction stress test?

In determining whether to postpone a contraction stress test, one critical condition to consider is cephalopelvic disproportion. This condition occurs when the fetal head is too large in relation to the pelvic opening, which can complicate labor and delivery. Performing a contraction stress test in the presence of cephalopelvic disproportion may introduce unnecessary risks, including fetal distress or complications during the testing process.

Thus, medical professionals would likely choose to delay the test until a more suitable assessment of the mother's and baby's readiness for labor can occur. It’s important to ensure that both the mother and fetus are in optimal condition for the test, and cephalopelvic disproportion presents specific concerns that warrant caution.

Conversely, other conditions such as a normal fetal heartbeat, gestational diabetes, or positive ultrasound results typically do not pose a direct contraindication to performing a contraction stress test. While they may require consideration during the overall evaluation of maternal and fetal health, they do not inherently lead to the postponement of the contraction stress test itself.