A common question among many women: if I get an ultrasound with a missed period, is it possible to detect pregnancy? It’s not uncommon to see women who are trying to get pregnant thinking if I am pregnant, the transvaginal ultrasound will show it. But did you know it’s not quite like that? Let’s understand why.
A late period, symptoms appear, and then you decide to have an ultrasound to see what’s going on. The thought is that if it’s an ongoing pregnancy, it will show up, you’ll see and hear the baby’s heartbeat — a dream come true, right? No! But it’s also not 100% of cases where pregnancy cannot be detected with a transvaginal ultrasound1. Actually, it is possible to discover a pregnancy through this exam, but in the vast majority of cases, it is NOT possible to detect an incipient (early) pregnancy in progress.
The reason is simple: there hasn’t been enough time for the baby to grow enough to appear on the ultrasound. When there really is an early pregnancy, up until the 5th week, at most the doctor (if experienced and skilled) can see a tiny gestational sac, a functioning corpus luteum, a thick endometrium and slight uterine changes. In these cases, it’s best to do a beta hCG test to be sure. In fact, this is the first test that should be done. A pharmacy pregnancy test, for example, detects pregnancy with great accuracy.
When Is It Possible to Detect Pregnancy by Ultrasound?
As I mentioned earlier, it is possible to detect pregnancy through an ultrasound, but only in some specific cases. When the woman has a transvaginal ultrasound after the 6th week of pregnancy. Before this, it’s very likely that the doctor will not really be able to diagnose pregnancy just using this exam. By the 6th week it’s possible to see the gestational sac and, in most cases, the baby, along with the yolk sac. Sometimes you can see and hear the heartbeat2, but since it is so tiny, just being able to see the heartbeat is already a huge thrill.
Now, when there is a more advanced pregnancy, it is possible to see the baby perfectly, as in the case of a woman five months pregnant who had no idea she was expecting. She left the office already knowing the baby’s sex and even had a name picked out (even though she was surprised and shocked too).
Another possibility is missing your period for a long time and all your tests coming back negative — a woman might think something is wrong and in the end, only discover the pregnancy by ultrasound! This, of course, is very rare, but it happens. For some reason, the mother’s body blocks the HCG in the blood and urine, making the pregnancy visible only by imaging. So, if you haven’t had a period for some time, with or without pregnancy symptoms3, you need to do a beta hCG test; if it’s negative and you keep missing your period, you need to see a doctor and have an ultrasound and may eventually detect the pregnancy. Remember that pregnancy is detected more than 6 weeks after conception, ok? When in doubt, always get tested.
See also: 5 Week Ultrasound – I Didn’t See the Baby, Now What?
