For many women, the moment you see a second line on a pregnancy test you feel a connection to the pregnancy beginning to develop. A rush of emotion follows that positive test, but it can still feel a bit abstract.
After all, your body isn’t likely to have changed much yet, and you can’t yet see or feel your baby.
But the first time you hear your baby’s heartbeat, that’s often when reality sets in.
It’s then you might begin to feel a stronger connection to your pregnancy, realising another little heart is growing inside you.
When Can You Hear Baby’s Heartbeat?
A baby’s heart begins beating at around 6 weeks. However, every pregnancy is unique and this can vary slightly. A big variable is the actual dating of your pregnancy. Dates are based on the first day of your last menstrual cycle. Ovulation takes place, on average, on cycle day 14, but it can actually vary quite a bit from woman to woman and even from cycle to cycle.
A baby’s heart begins to beat around 6 weeks of pregnancy, which is 6 weeks from the first day of your last menstrual cycle. This means in some pregnancies it might begin just before 6 weeks, and in others it might begin just after 6 weeks.
You Can Hear Baby’s Heartbeat Via Ultrasound Between 6 and 8 Weeks
Baby’s heart might begin a bit before 6 weeks but, due to its size, it’s unlikely you will see it via ultrasound and definitely unlikely you will hear it via ultrasound.
Depending on the mother’s size, the position of the uterus, where baby is located, and accuracy of dating, some women are able to hear the heartbeat via ultrasound between 6 and 8 weeks, but often closer to or after 8 weeks.
Also, while it might be possible to hear the heartbeat early on, many providers choose only to watch the heartbeat via ultrasound, and not attempt to listen until later in pregnancy. At 6 weeks, baby is still very small – about the size of a lentil. At 8 weeks, baby is the size of a kidney bean.
A Doppler Can Be Used Around 10 Weeks Or Later
A Doppler is a small, handheld device with a cord and probe that is placed on your lower abdomen. A Doppler uses the same technology as a pictured ultrasound, but it’s used to hear baby’s heartbeat and not to produce an image.
Although the heart begins to beat at around 6 weeks, due to baby’s size it cannot be heard via doppler at that stage. Typically, most maternity care providers will attempt to use a Doppler between 10 and 14 weeks. Occasionally, a heartbeat can be picked up via Doppler at 8-10 weeks.
Exactly when you’ll be able to hear the heartbeat via Doppler depends upon your size, the position of the uterus, the location of baby, and the accuracy of dating your pregnancy.
What If We Can’t Hear The Baby’s Heartbeat?
Doppler use is limited during the first trimester and the early part of the second. An ultrasound, though quite accurate, is still limited. If a heartbeat cannot be heard via Doppler before 16 weeks, it’s possible that the Doppler is simply unable to pick up the heartbeat, due to baby’s location, inaccuracy of dating, etc. Your providers might attempt again further in your pregnancy or refer you for an ultrasound, depending on how far along they suspect you to be.
If an ultrasound is unable to detect a heartbeat, it’s possible the dating of your pregnancy was inaccurate. If this happens less than 8 weeks from your last period, your provider might recommend a repeat ultrasound after a few days, to ensure there wasn’t an error in dating. Unfortunately, if your dating is accurate and you’re further along, no heartbeat indicates a miscarriage.
Are Dopplers and Ultrasounds Safe?
Given the nature of pregnancy and medical ethics, it’s rare for double-blind studies to be completed to confirm the safety of procedures or medications during pregnancy. For this reason, ultrasounds and Dopplers, like many other things, have never been proved safe; neither have they been proved to carry risks.
Ultrasound imaging and Dopplers utilise sound waves to capture an image or to hear the heartbeat. These waves can cause tissue to heat. Because of this, there is reason to assume that there’s potential for cells to be affected by the increase in temperature. However, there is no proof that it can, or does, cause problems for a developing baby.
This is why ACOG and the FDA recommend that only healthcare professionals utilise Dopplers and ultrasounds, and only when medically necessary. Using a Doppler for about a minute or two, once or twice per month, for prenatal care, is unlikely to cause any concerns. The benefit of determining baby’s heart rate at prenatal appointments is likely to outweigh any potential risks.
However, some maternity care providers prefer to use a fetoscope, which is a stethoscope with a cone-like structure instead of the typical circle at the end. This poses no risk to developing babies, but isn’t typically used until after 18-20 weeks.
Are Dopplers And Ultrasounds Necessary?
Depending on who you ask, you’ll probably get different answers. It’s certainly possible to receive prenatal care without ultrasound or Doppler use. Growth can be monitored via fundal height and palpation, and baby’s heart rate can be checked with a fetoscope after 18 weeks.
Where there are no concerns, some women and providers like to assume all is progressing well, and only utilise interventions when red flags exist. Others prefer to utilise Dopplers and ultrasounds to monitor a pregnancy early on, with or without the presence of red flags.
Hearing your baby’s heartbeat for the first time is often a life-changing moment. The reality of your pregnancy begins to sink in and you have more of a connection with the little baby you can’t quite feel yet. Many women will see their maternity care provider for the first time at about 8-10 weeks . Although it’s possible to detect a heartbeat, via ultrasound, prior to that appointment, many maternity care providers don’t feel it’s necessary, in the absence of any concerns.