To determine the likelihood of pregnancy failure based on the given fetal heart rates, let's analyze each option individually.
1. 150 bpm at 8 weeks:
- At 8 weeks, a fetal heart rate of 150 bpm is generally considered normal and does not indicate a high likelihood of pregnancy failure.
2. Greater than or equal to 155 bpm at 6.3 to 7 weeks:
- During the period of 6.3 to 7 weeks, a fetal heart rate greater than or equal to 155 bpm is typically within a normal range and does not suggest a high risk of pregnancy failure.
3. 120 to 130 bpm at 9 weeks:
- At 9 weeks, a fetal heart rate between 120 to 130 bpm is usually still within the normal range and not indicative of increased risk for pregnancy failure.
4. Less than 110 bpm at 6.3 to 7 weeks:
- A fetal heart rate of less than 110 bpm during 6.3 to 7 weeks is significantly lower than the normal expected range at this stage of pregnancy. It is often associated with a higher risk of pregnancy failure because a lower heart rate can indicate potential issues with fetal development or distress.
Analyzing these statements, it becomes evident that:
- Option (d): "Less than 110 bpm at 6.3 to 7 weeks" is most likely to be associated with pregnancy failure. This lower heart rate at such an early stage is a concerning sign and poses a higher risk compared to the other options provided.
Thus, the correct answer is:
d. Less than 110 bpm at 6.3 to 7 weeks
This option is the most concerning regarding the likelihood of pregnancy failure due to the low fetal heart rate at that critical development stage.
