How does Plan B work?

Question

Does anyone know what percentage chance of failure this has if the second dose had been vomited out? Basically, only half of the dose made it thorough. If fertilization happened before I took the pill and it still attaches, will this cause any birth defects or deformations to the baby?

Answer 1

In works as high dose birth control but with different ingrediants. If will stop ovulation, it will prevent sperm from getting to the fallopian tubes (where the egg is fertilized), and it will even inhibit the ability of the fertilized egg to stick to the wall of the uterus.

There is about an 8% chance that you will get pregnant in any given sexual incounter and when taking the pill (both), this reduces to 1%.

As for vomitting the second dose, if it was with in an hour of taking to pill, you should contact your doc to see what the next step should be. There are other options and there may be the chance to take another dose.

By vomitting in the first hour, you may push your risk to 2% or so.

Nausea is common and 1 in 4 will experience it and 1 in 20 will vomit so don't think that it is a pregnancy sign.

As for if it attaches reguardless of the pills block against this then it is very unlikely that it will do harm to the child. It is flushed out of your blood stream with in 24 hrs and the embryo will develop from there with no effects. If you were already pregnant previous to taking the pill that would be a different story as may hormones are needed to make the kid and the pill disrupts that temperarily.

Call your doc/their nurse and get some info from them. That is the best way since they know your history and everything else.

Answer 2

It works the same way as the birth control pill, by inhibiting ovulation. If fertilization has occurred already, it is ineffective. There will be no effects on the baby, as the hormones that are used to inhibit ovulation are the same hormones that maintain the uterus throughout pregnancy.