Which fetal heart rate is considered concerning during the second trimester of pregnancy?

During the second trimester of pregnancy, a fetal heart rate that is persistently above 160 beats per minute, such as 180 beats per minute, is considered concerning. This elevated heart rate, known as fetal tachycardia, can signal potential issues such as fetal distress, maternal fever, or other underlying complications. Normal fetal heart rates typically range from about 120 to 160 beats per minute in the second trimester, so sustained rates significantly above this range are monitored closely as they may indicate the need for further evaluation or intervention. Recognizing and addressing abnormal fetal heart rates is crucial for ensuring the health and well-being of both the fetus and the mother.