When Is the First Ultrasound Performed?
Ultrasound is an imaging technique used to confirm pregnancy. Although the gestational sac can be visible as early as week 5, it is recommended to perform the first ultrasound between weeks 6 and 8 of pregnancy to ensure clear visualization.
The first ultrasound is typically performed transvaginally, as this method provides a clearer view of the gestational sac and enables earlier detection of the fetal heartbeat. From week 10 of pregnancy, abdominal ultrasounds are performed.
The objectives of the first ultrasound are:
- To confirm the implantation of the embryo in the uterus and rule out ectopic pregnancies (outside the uterus).
- To determine the number of implanted embryos.
- To detect the fetal heartbeat. If the first ultrasound is done in week 6, the embryo’s heartbeat may still be undetectable, but this does not necessarily mean there is a problem. As gestational age increases (weeks 8 and 9), the heartbeat becomes easier to detect.
- To estimate gestational age: The crown-rump length (CRL) of the embryo is a crucial measurement for estimating gestational age. This parameter is especially useful in women with irregular menstrual cycles.
- To assess the size and shape of the gestational sac, which helps identify possible early embryonic abnormalities.