Ultrasound can usually detect a fetal heartbeat at 6-7 weeks of pregnancy, when the babys length or crown-rump length (CRL) is 7mm. If the CRL is less than 7mm and no heartbeat is seen, this may be because the embryo is too young. You will be offered a re-scan.

What type of ultrasound is done at 7 weeks?

When a transvaginal ultrasound is done at seven weeks gestation, the transducer is placed in the mothers vagina and the sound waves are transmitted via her cervix and directly into the uterus. With this form of scan, it is not as necessary for the mother to have a full bladder.

How many CM is a 7 week fetus?

Your baby when youre 7 weeks pregnant The embryo is about 1 cm long from head to tail – about the size of a coffee bean. Body parts are usually out of proportion at this stage.