Many people have asked me about a chemical pregnancy.
A chemical pregnancy is simply a very early miscarriage.
If your urine pregnancy test(UPT) is positive, it is more than 99% accurate that you are pregnant.
If you had bleeding a few days later and then a repeat UPT test becomes negative, this means you had an early miscarriage.
Personally, I do not like the term ‘chemical pregnancy’, because it is as if there is a denial a real pregnancy happened and that pregnancy had miscarried. Personally, I think it is much better to say that you had a ‘miscarriage’ even though it was never seen on an ultrasound scan.
This is because A POSITIVE UPT confirms a pregnancy. This is because the false positive rate is so low, less than 1%. Thus A POSITIVE UPT is more than 99% accurate that a pregnancy has occurred. A UPT detects the HCG hormone produced by the embryo. False positive is very rare and can occur if you had a tumour which produces HCG hormone or if you had HCG treatment.
Thus, many women may have had miscarriages that they didn’t know happened, because they thought their periods were a few days late and they never did a urine pregnancy test, so they did not know that they were pregnant. Miscarriages are more common than you think and can happen to any healthy woman.
Can you imagine, in the past, how pregnancies were diagnosed without the UPT kit that you could buy and use at home? The UPT was only invented in 1967, but it was not until 1976 before the home UPT kits were approved and sold to the public.
Many more women before 1976 had miscarried without knowing they were even pregnant because they never had a home UPT kit.
Before 1967, they used the ‘frog test’ to test if a woman is pregnant.
The female African Clawed Frogs responded to the HCG hormone in a pregnant woman’s urine. When a pregnant woman’s urine is injected into the back of the skin of a female African Clawed Frog, the frog would ovulate and release frog eggs within 18 hours. If the urine of a non-pregnant woman is injected into the frog, then no frog egg would be released. This is a highly accurate test.
Aren’t we lucky today to have the home UPT kit that you could buy from the shops, and we don’t have to wait 18 hours to see if the frog laid eggs.
I am certainly very grateful that my job as a Gynaecologist is so much simpler today 😅