Answer from: Raúl Olivares, MD
Assuming that the implantation means that you are going to have a positive pregnancy test, what we recommend after the patient contact us confirming that she is pregnant – the first thing that we tell her is to continue taking progesterone until we confirm that there is an embryo inside.
Then, we schedule the first scan 2 weeks after the positive pregnancy test. The idea behind this first scan is to make sure that there is a sac inside the uterus, which will allow us to discard the ectopic pregnancy. In some cases, we can even see that there is an embryo with a heartbeat. That’s not really mandatory in a 5-6 weeks scan, but if you can see it, that’s something that can be very reassuring. If this scan is positive, and we confirm that there is a sac, and everything looks fine whether there is an embryo or not, again, we schedule a new scan 2 weeks later. In that second scan, you must see an embryo, there is no error. The reason is that, in this case, we know if the patient is pregnant, so it’s very easy for us to work out the next steps and what we must see in each scan.
In a natural cycle, it could happen that the patient has ovulated 1 week later for any unexpected reason, and you can see the differences in what you see on the scan and what you expect based on the previous period. In IVF, or any other treatment, you know the day of the embryo transfer, so it’s easier to work out the different steps. On the second scan, which is scheduled for around 7-8 weeks, you must see an embryo. The embryo at this initial stage has grown very fast, they may grow up to 1 centimetre per week, that’s something that makes a huge difference between the first and the second scan, so you must hear the heartbeat, at that stage, it should be around 180 beats.
If that second scan is okay, we discharge the patient. They can start living a normal life with a normal pregnancy, and when they stop taking progesterone, especially if they have done IVF, they can stop it. If they were on hormone replacement therapy, which is something that means they have not ovulated. Then they must continue with oestrogens and progesterone until the placenta takes over. That happens around week 11, we can then tell them when they can stop the treatment.
