Fetal bradycardia is defined as :
**Core Concept**
Fetal bradycardia refers to a decrease in the fetal heart rate below a certain threshold, which is a critical indicator of fetal distress. This condition is typically assessed in conjunction with other fetal monitoring parameters, such as fetal movement and uterine contraction patterns.
**Why the Correct Answer is Right**
Fetal bradycardia is defined as a decrease in fetal heart rate to less than 110 beats per minute (bpm) for at least 10 minutes, or less than 100 bpm for at least 5 minutes. This definition is based on the understanding that a normal fetal heart rate ranges from 110 to 160 bpm. A decrease in fetal heart rate can be caused by various factors, including placental insufficiency, umbilical cord compression, or maternal hypoxia. The detection of fetal bradycardia triggers immediate medical evaluation and potential interventions to ensure fetal well-being.
**Why Each Wrong Option is Incorrect**
* **Option A:** A fetal heart rate between 100 and 110 bpm is considered normal, not bradycardic.
* **Option B:** Fetal bradycardia is not defined by a prolonged heart rate below 90 bpm.
* **Option C:** A heart rate above 160 bpm is considered tachycardic, not bradycardic.
**Clinical Pearl / High-Yield Fact**
In clinical practice, it's essential to remember that fetal bradycardia can be a non-reassuring sign and may require prompt medical evaluation, including ultrasound assessment of fetal well-being and potential cesarean delivery.
**Correct Answer: D. Less than 110 bpm for at least 10 minutes, or less than 100 bpm for at least 5 minutes.**