Should I continue taking Atenolol?

Question

Ok, so I took a home pregnancy test last night and it was positive. I called to get an appointment with a doc but I can't get in until next week or maybe the week after. I take atenolol because I had a heart arrhythmia a few years ago. Should I keep taking it until I see the doctor or stop? If I stop I'm scared I will have the arrhythmia again but if I keep taking it I'm scared it will hurt the baby. I did some research on the drug and some sites say it has no proven effect on pregnancy and some say it does. It is pregnancy class D but I don't know what that means.

Answer 1

contact NHS direct 0845 46 47

Answer 2

Azrielle:

Continue taking your atenolol and see your cardiologist!

I would recommend three things:  One, trust the medical community that has looked at the risk of beta blocker therapy and pregnancy - there have been several studies on atenolol, I read the NEJM report and find it a decent study.  Here is a website that cites the same article in non-MD language:

http://parenting.ivillage.com/pregnancy/...  

While beta-blockers as a class have a clear impact on fetal birth weight, atenolol has not been clearly implicated in birth defects.

Second:  Talk to your OB/GYN and verify your pregnancy.  Home kits are great, but the reliability of specific kits is dependent upon the manufacturing technique and the age of the product.  A blood test for pregnancy also quantifies the amount of placenta hormones in your blood stream and can help pinpoint how far along you are in your pregnancy and if there are any initial concerns.

Third - and foremost - this needs to be asked of your cardiologist, not the run of the mill yahoo user or the chance physician on the board.  While I am a physician, your own cardiologist knows you, the type of arrhythmia being treated, and the amount of atenolol you are taking.  Likely he or she can drop the dosage if you ask and discuss your concerns - without any loss of control of the arrhythmia.  Or switch to labetolol which doesn't seem to have the reduced birth weight association.

Other answerer's are right about "D", it signifies that there is a negative effect in pregnancy - but the category doesn't say how severe an effect.  In reality, it has been known to reduce fetal growth rate so you can (at high levels of beta blockade) bear a lower birth rate baby.  There are rare instances of birth defects while on atenolol - these are not clearly due to the atenolol so we aren't really sure about the statistics here.

Answer 3

it should be alright for the time being.

Class A: Controlled human studies have demonstrated no risks to the fetus.

Class B: Presumed safe, based on animal studies; no well-controlled human studies are available.

Class C: Safety is uncertain; data from human studies do not exist, and animal studies have shown some question of risk to the fetus. Pregnant women may take these medicines if they clearly need them.

Class D: Evidence suggests the possibility of the medication causing birth defects or other problems, but a pregnant woman still might need to take it for her own medical needs.

Class X: Proven risks to the fetus outweigh any possible benefits to the mother

and congrats on the baby =]