OP: Does being on the pill interfere with pregnancy tests?

You always have to tell your doctor what BCP you are on, all medications/supplements you take, when they prescribe you a new medication such as an antibiotic [or any additional medication]. Some meds are known to decrease the efficacy of the BCP; furthermore, you should check with the Pharmacist.

When in doubt use a back up method of birth control until you have completed the medication and have your period. The next pack is fine.

Yes, you can still do a home pregnancy test even when on the pill. For the future always as the physician, or prescriber, and the pharmacist about drug interactions. If in doubt use another method.

sera300

Posted: 29 Sep 23:52

Interesting question that you will probably get alot of different responses to. There has been anecdotal evidence suggesting that certain medications can lower the effectiveness of birth control pills, especially certain antibiotics, antifungals, seizure medications....however the studies are not all that good and most are from many years back. Some of the newer studies show that this may not be as big of a problem as once thought but i have my own take on the issue. I agree that you should always notify your healthcare provider of the medications you are taking (eventhough OCP's somehow get left off the list of current medications for some reason), and I always instruct my patients to use an alternative form of BC when taking antibiotics, antifungals....I personally have 2 children that I affectionately refer to as my Cipro babies. My wife has always been very good about taking her OCP's but has a history of kidney stones and UTI's that often warranted being placed on antibiotics. Two of our 3 children were conceived while on Cipro, yet if you look into many of the studies, Cipro eventhough once thought to be at the top of the offender list has not been shown to reduce the effectiveness of OCP's. One of two things must be at play here, either my wife didn't take the OCP and flushed them down the toilet to get pregnant or Cipro does reduce the effectiveness of the pill! If you do look into the studies make sure to find out who is sponsoring the study. One of the first things we are taught with regard to medical studies that either refute or support a specific claim is to make sure who is backing the study. Remember, for every study you find that supports a specific claim, you can probably find one that refutes it as well. Most of us will probably always recommend alternative BC methods to our patients when taking drugs thought to decrease OCP effectiveness and until some significant studies come out that changes how the majority of the medical community views this topic, I will continue to do the same.

As for taking BCP's, SERA300 is right on in that urine and serum pregnancy tests are not effected by using OCP's. The tests are looking for a specific hormone that is released by the placenta (Human chorionic gonadotropin - HCG) to maintain the pregnancy. There are a few medications out there that lower HCG levels which can potentially give a false negative result just as there are medications and certain medical conditions that can give you a false positive one. Once again this stresses the importance of disclosing your medications to the doctor before having such a test. If you use an OTC urine pregnancy test and it comes back positive, please see your health care provider as soon as you can so that the necessary workup and evaluation can be completed.

RAM MD

Posted: 29 Sep 23:52

Maybe some of the studies are old and most are flawed. There is a statistical relationship between some of the meds RAM is talking about and pregnancy whilst on hormonal contraception. The same is true for many supplements. Some of these studies are large and some are small but there are some indications that they interfere with hormones preventing pregnancy. They do not affect home pregnancy tests as RAM indicates.

I recommend to my patients that they use two home pregnancy tests of different brands twelve or more hours apart. These tests have become quite good in the last few years but any of them will show positive if left in urine for a prolonged time. Also check the expiry date on the package. Then, your doctor can give you the rest of the story - prenatal care should be started as soon as pregnancy is noted.

Brandye

Posted: 29 Sep 23:52