There seems to be some confusion lately--especially by the current administration--about how exactly the birth control pill works. Em & Lo started the discussion, but I wanted to weigh in with the medical point of view. The birth control pill prevents pregnancy in several ways:
  • Primarily, the pill prevents ovulation. No egg, no chance of pregnancy. Most months, a woman taking the pill won't release an egg.
  • The pill changes your fallopian tube motility. If an egg is released, the pill makes it harder for it to travel to the uterus.
  • The pill thickens your cervical mucus. This thickening makes it difficult for sperm to get to an egg if one is there.
  • The pill alters your uterine lining. So if an egg was released, and if it manages to get through the fallopian tube, and if sperm were able to get to the egg, and if the egg was then fertilized--and that's a whole lot of ifs--the different lining makes it harder for a fertilized egg to implant. So at no point does the pill interfere with a fertilized egg: it just makes it less likely that the egg will land and become a pregnancy. It is this function of the pill that causes such a ruckus among those who hold that disruption of implantation is the same as an abortion--even though this function of the pill rarely comes into play.