Pregnancy is a time of happy anticipation, but it can also be a time of worry. Every mother is concerned about her baby's health and the sound of a healthy heartbeat brings great relief. Relief can easily turn to anxiety if you think the heartbeat seems faster or slower than normal. According to the American Pregnancy Association, it is normal to have questions and worries about healthy fetal development, but it is important to keep in mind that every pregnancy is different.
Methods of Measurement
Early in pregnancy, fetal heart rate is measured using ultrasound. During transvaginal ultrasound, the technician will insert the transducer into the vagina. The transducer is moved across the abdomen in transabdominal ultrasound. According to the American Pregnancy Association, transvaginal ultrasound can detect development a week earlier than transabdominal. Later, a Doppler device that converts sound waves into audible tones can be used to detect a heartbeat. A fetoscope, similar to a stethoscope, is also used to hear heartbeats. During labor, a belt with a Doppler device may be used, or if necessary an electrode can be run through the vagina to the baby's scalp, according to the American Congress of Obstetricians and Gynecologists or ACOG.
Normal Rates
A heartbeat can first be detected at around 6 to 7 weeks of gestation. The normal rate at this age is 90 to 110 beats per minute. Around the ninth week, the heart should be beating at 140 to 170 beats per minute, states the American Pregnancy Association. Fetal heart rate normally increases with movement. During labor, the heart rate may vary between 110 and 160 beats per minute. A decrease in heart rate is normal during a contraction as long as the rate comes back up.
What Does the Heartrate Mean?
The doctor uses fetal heart rate as one way to assess the health of the baby. A heartbeat detected around 7 weeks by ultrasound is a good indicator that the pregnancy is healthy. During labor, a heart rate that does not change or one that is too high or low can warn the doctor of problems, notes the ACOG. A high risk of miscarriage is indicated by a heartbeat less than 90 beats per minute at 5 to 8 weeks gestation, according to Obstetric Ultrasound.
Abnormal Heartrate
When an abnormal heart rate is found, the doctor will decide what treatment is necessary, which may include emergency delivery in later stages of pregnancy. An abnormal heart rate can be caused by a variety of conditions, including compression of the cord. Heart rate problems may signal that the baby is not getting enough oxygen, might have an infection or be anemic.
Home Monitors
Fetal heart monitors for home use are available for rent or purchase. ABC News Health warns against using a home monitor, however. Mothers may delay seeking medical care when a problem occurs because home heart rate monitors provide a false sense of reassurance. Professionals are trained to take results in context with other findings before diagnosing. The mother can also mistake her own pulse for the fetal heartbeat. In addition, home monitors are often not high quality.
References
- American Pregnancy Association: Concerns Regarding Early Fetal Development
- ABC News Health: Home Fetal Heartbeat Monitors May Deceive
- Medline Plus: Fetal heart monitoring
- The American Congress of Obstetricians and Gynocologists:Fetal Heart Rate Monitoring During Labor
- Obstetric Ultrasound: A Comprehensive Guide to Ultrasound Scans in Pregnancy
