During fertility treatment, you may undergo several ultrasounds as part of treatment. But for many who have fertility issues, the six-week ultrasound can be particularly exciting. That’s because around this time, fertility doctors and ultrasound specialists are looking at evidence of conception — that is, a baby!
The difference between a sonogram and an ultrasound
The terms sonogram and ultrasound are often used in place of each other, though there is a difference. An ultrasound is a procedure that uses high-frequency ultrasound waves to create visual images that can be used to observe the health and growth of an embryo. On the other hand, a sonogram is the actual picture produced by an ultrasound (it’s the image your doctor can print for you, and that you can share with family and friends).
Why doctors want to see a sonogram at six weeks
If you’ve been undergoing fertility treatment, a six-week ultrasound is often one of the first times you’ll be able to actually view your baby in the womb. Doctors often want to evaluate a sonogram at six weeks because it’s the first glimpse that your pregnancy is developing as it should. Specifically, doctors will be reviewing the sonograms from your ultrasound for these reasons:
Detecting a heartbeat: The six-week ultrasound is often the first time that an ultrasound technician or doctor is able to visibly see (and sometimes hear) a heartbeat. This is the first clue that pregnancy is developing as it should be; in cases where a heartbeat is not visible or audible, doctors may be able to determine if the pregnancy is not viable (meaning a miscarriage is possible). Although the embryo’s heartbeat is a first clue to the development process, being unable to see it is common, simply because at this time the embryo is so small. If a heartbeat isn’t detected, but your doctor can see the embryo, they may perform a vaginal ultrasound for better results, or have you return within a week or two to try again.
Proper development: From examining your six-week sonogram, a doctor can determine that the embryo is developing as it should. At six weeks, a sonogram can show the shape of the developing embryo, which can be measured. These measurements can help determine when you got pregnant, and also if the embryo is growing at the proper rate. A six-week sonogram often also shows the developing yolk sac and chorionic sac — two vital components that help nourish the embryo until the placenta and umbilical cord form.
Ensuring the right placement: When evaluating the six-week sonogram, your doctor will be able to determine that the embryo is developing in the right spot. During the ultrasound, your healthcare provider will be looking to make sure that the embryo is properly placed in the uterus, and not anywhere else, such as the fallopian tubes, ovary, or cervix. If a doctor identifies any issues with placement, also called an ectopic pregnancy, they will be able to counsel you on how to move forward.
Previous miscarriage: If you previously had a miscarriage, your doctor may want to observe this pregnancy early to ensure that it is developing as it should. Sometimes, in cases where women have multiple miscarriages, a fertility doctor will evaluate the embryo this early to determine possible issues that could be leading to pregnancy loss.
Understanding the sonogram and what you’re seeing
At the time of the six-week ultrasound, the embryo in your uterus measures between two and four millimeters (or about 1/6 to 1/4 of an inch) — that’s about the size of a pea. Most ultrasounds at this stage use standard 2D technology (while 3D ultrasounds are available, many doctors’ offices still use the tried-and-true 2D machines), and are in black and white. Liquids produce the dark black areas, while the white portions of the image will show solid tissue, such as bones. Early sonograms will show a small yolk sac; within that bubble will be the embryo, which may look to you like a small bean or piece of rice. During the time of the six-week ultrasound, the embryo will be in a tight C-shape, and it will be forming the head, legs, and umbilical cord.
What happens if you don’t see anything on your six-week sonogram
Although doctors are usually able to detect and confirm a pregnancy at six weeks, sometimes an ultrasound does not produce results. In some cases, it could just be that the pregnancy is still in the very early stages, where it is not possible to see the embryo just yet. In other cases, it can be a situation where the body has had a miscarriage, or a chemical pregnancy — a situation where implantation doesn’t occur despite missing your period and having high levels of pregnancy hormones in the body. In any case, an ultrasound that doesn’t produce results will encourage your doctor to follow up within three days to a week to try again.