In a routine and healthy pregnancy, it isn’t uncommon to have only one or two ultrasounds for the duration of the pregnancy.
While some women opt out of all ultrasounds, many choose to have an anatomy scan midway through the pregnancy, and a few will have scans early in pregnancy, to check dating and viability. Whether you have early ultrasounds or not is often a personal preference, combined with your personal medical history.
For these reasons, each woman is likely to see or hear her baby’s heartbeat at different stages in her pregnancy. Some women will have early ultrasounds to confirm pregnancy, or to check the location of the pregnancy if there’s any concern (e.g. Some scans can detect a gestational sac around 4-5 weeks of pregnancy, but that’s still too early to detect a heartbeat.
Your pregnancy is dated from the first day of your last menstrual cycle.
If, based on your last period, you’re 6 weeks along but you ovulated a few days late, it’s possible that the scan was just too early.
Later in pregnancy, genetics takes over your baby’s growth, and your baby will be measured in terms of percentiles.
A positive test lets you know you’re pregnant, but seeing or hearing baby’s heartbeat often means the reality of your pregnancy will begin to sink in.
If you haven’t had any signs of a miscarriage and are less than 8 weeks pregnant, it’s possible that you’ve simply had a scan too early.
Even with all the variables, it’s very likely you will see a heartbeat by 7 weeks and extremely likely by 8 weeks of pregnancy.
While many mothers are able to see the heartbeat around 6 weeks, some maternity care providers prefer to wait until 7.5 weeks or more.
So your baby may be on the 30th percentile or the 80th percentile, but still be normal.
Unfortunately, if you’re around 8 weeks of pregnancy, and your dating is accurate, a lack of heartbeat usually indicates a miscarriage.
While cell damage hasn’t been documented concretely, the potential is enough for the FDA and ACOG to recommend limited use.