Doxycycline and Pregnancy After IVF: Risks & Considerations

Question
Hello Doctor,
I came to know last week that I am pregnant (through blood tests). I did an IVF (this was my first attempt).
5 days after the embryo transfer into my uterus the RE found that there is a lot of fluid accumulation in my abdomen because of Ovarian Hyperstimulation.
For removing the fluid - RE had to give me Doxycycline.
I came to know 3 days after that day when I was given Doxycycline that I am pregnant.
I found out that Doxycycline is a Category D medicine - and is harmful to the fetus.

I am very worried now. Could this cause the fetus to be harmed this early?

Normally when should a person stop taking Category D medicines - (is it even when they are trying for pregnancy; or is it only after they find out they are pregnant)?

Please give me a honest advice - enen though it might be tough to swallow; since I want to know the truth.
Please let me know.

Answer
Doxycycline is a form of Tetracycline, which is a class of antibiotics that should be used with extreme caution, if at all, in pregnancy. They are, indeed, catagory D medications. Problems attributable to the use of the tetracyclines during pregnancy can be classified into four areas: adverse effects on fetal teeth and bones, maternal liver toxicity,and  congenital defects. Tetracycline can cause staining of deciduous teeth (a brownish stain) and depression in bone growth. It can cause acute fatty liver and hepatotoxicity. It has not been found to be a causative agent of major birth defects. Inadvertent use of tetracyclines in the first trimester would not prompt a recommendation for termination. I doubt that the course of Doxycycline that you took will cause any harm to the baby or to the pregnancy. Good luck to you.