I am on the Depo-Provera shot for birth control, and I think I might be pregnant. What are the chances of getting pregnant while on Depo?
If you've kept up with your schedule of Depo-Provera shots (usually at 3 month intervals), it's highly unlikely that you're pregnant. There is a failure rate, but it's extremely low. I've only had one patient in 20 years get pregnant on this method.
The fact that Depo-Provera causes periods to stop as one of the side effects is sure to make one wonder from time to time. Just remember that this method has a lower failure rate than even the birth control pill. But... What if you really are pregnant?
The Depo shot works by slowing releasing a synthetic hormone, progestin (a form of progesterone), which prevents pregnancy. Progesterone has been implicated in the past for causing deformities in a developing baby's limbs. But these worries have been challenged by subsequent studies demonstrating that such a problem may not exist at all. In my practice, if a patient were to be pregnant during the time she received one of these shots, I wouldn't worry about this complication. Just to be safe, however, I'd order an ultrasound to examine the fetus, though. But this wouldn't (or shouldn't) happen if you get a pregnancy test before each injection.
So relax, you're probably not pregnant. But if there's any doubt, have your health care provider do a pregnancy test. I'm betting it will be negative. And if I'm wrong and you are pregnant, the complication rate from this exposure is theoretical at worst and probably a non-issue.