Low Beta hCG: what happens when the result isn’t around 100 mIU/ml
The moment all future mothers anxiously wait for following assisted reproduction treatment finally arrives, called the beta hcg wait. These days are tough, and after all the tests, injections and treatment, the wait feels even longer…
But after all that waiting finally comes the big moment. You take a pregnancy test and it comes back positive. Your heart starts to race and you go to the clinic where they order the Beta hCG hormone blood test, but your level is low. The doctor congratulates you, but is a bit wary…
What do we do when the Beta hCG level is low?
The first thing you should know is that the pregnancy test is generally done 15 or 16 days after ovulation (or theoretical ovulation), and the Beta hCG level which indicates that everything is progressing as it should will be around 100 mIU/ml.
A normal level is a good indicator that the pregnancy is viable. In these cases the patient will continue taking the same medication and the clinic will have the future mom return for her first ultrasound scan, generally two weeks after the pregnancy test.
At this point her Beta hCG level will be over 1,000 mIU/ml. It is during this ultrasound scan that a properly progressing pregnancy will be confirmed when the doctor visualises the gestational sac in the uterus, the embryo and its heartbeat.
However, when the result of the Beta hCG is less than 100 mIU/ml it is necessary to monitor its development, keeping in mind that it doubles every 48-72 hours. At our fertility clinic in Spain, for example, we always re‑test patients’ β-hCG levels after 48 hours when the initial result is less than 80‑90. If the second result shows that the level has doubled, this tells us that the pregnancy is progressing correctly and we can then schedule the patient for her first ultrasound.
In certain cases, when a patient’s beta hCG level is too low, we must prepare ourselves for the worst in addition to re‑testing after 48-72 hours… In these cases we need to understand that the pregnancy may not be progressing as it should, and that we could be looking at a biochemical pregnancy, miscarriage or ectopic pregnancy, among others.
Though you should keep in mind that a normal result for the first Beta hCG test should be around 100 mIU/ml, if your level is lower than this you shouldn’t start worrying just yet. After 48-72 hours you will take another pregnancy test to confirm that it’s increasing as expected. As we said before, you must remember that a normal pregnancy may initially present low β‑hCG levels and nevertheless result in a perfectly healthy baby.