What is a common risk factor for prolonged decelerations?

Prolonged decelerations are commonly associated with hypertonic contractions, which are contractions that occur more frequently than normal, with little to no resting time between them. This type of contraction can lead to decreased oxygenation to the fetus as it puts additional stress on the baby's heart. The frequent and intense nature of hypertonic contractions can reduce blood flow through the placenta, causing intermittent fetal heart rate decelerations that can become prolonged.

In contrast, normal fetal positioning tends to support optimal fetal health and does not contribute to the risk of decelerations. Post-term pregnancy can certainly have risks, but it is not directly linked to the occurrence of prolonged decelerations in the same way hypertonic contractions are. Maternal hydration is typically beneficial and helps maintain a healthy uterine environment, further reducing the risk of complications such as fetal heart decelerations. Therefore, hypertonic contractions stand out as the primary risk factor for prolonged decelerations in the fetal heart rate monitoring context.