You're actually both right when it comes to the implantation versus fertiliztion debate; I'll C&P straight from a reputable source, the Lexi-Comp Drug Information Handbook, Online Edition (I think the print version is on the 18th).
"Combination hormonal contraceptives inhibit ovulation via a negative feedback mechanism on the hypothalamus, which alters the normal pattern of gonadotropin secretion of a follicle-stimulating hormone (FSH) and luteinizing hormone by the anterior pituitary. The follicular phase FSH and midcycle surge of gonadotropins are inhibited. In addition, combination hormonal contraceptives produce alterations in the genital tract, including changes in the cervical mucus, rendering it unfavorable for sperm penetration even if ovulation occurs. Changes in the endometrium may also occur, producing an unfavorable environment for implantation. Combination hormonal contraceptive drugs may alter the tubal transport of the ova through the fallopian tubes. Progestational agents may also alter sperm fertility."
So "the pill" prevents ovulation (more or less for sure), theoretically prevents implantation, and prevents sperm from even reaching the egg in some cases.
You are also correct about other medications causing problems. The FDA rates drugs into "pregnancy categories" A, B, C, D, and X. As and Bs generally have good data to support their use in pregnancy; As are "no risk whatsoever" and as such the only drugs in the category are prenatal vitamins and folic acid. B indicates strong evidence that the drug is not harmful. C says there have been no controlled studies, but risk is possible; animal studies may have shown risks. D says that risk is likely and there is evidence backing the assertion that the drug not be used in pregnancy. X is no fucking way, don't use this in pregnancy, you will screw up the baby (thalidomide, Accutane, misoprostol [a known abortifacient], alcohol, etc).
Considering that it is not always obvious that a woman is pregnant it's actually possible to do a lot of damage to a fetus that she doesn't even know is there. All three of the drug classes you mentioned contain drugs in the D and X categories. It's not just heavy-duty stuff like chemo; OTC ibuprofen can cause premature closure of the ductus arteriosus, the vessel that shunts blood so that a baby can get oxygen despite their lungs being full of fluid.
As a side note, sometimes pharmacists do need to know if you're using birth control for something other than to control birth, namely if you need to have it billed in an odd manner. Most insurance companies say one pack per 28 days; one cycle per cycle. Some people have medical reasons to skip their placebo week, in which case the pharmacy has to bill one pack per 21 days. Sometimes insurance companies require documentation that the pill is being used for, say, endometriosis instead of contraception. How legitimate you think that this practice is is up to you, but insurance companies do have a right to know what they're paying for.
no subject
"Combination hormonal contraceptives inhibit ovulation via a negative feedback mechanism on the hypothalamus, which alters the normal pattern of gonadotropin secretion of a follicle-stimulating hormone (FSH) and luteinizing hormone by the anterior pituitary. The follicular phase FSH and midcycle surge of gonadotropins are inhibited. In addition, combination hormonal contraceptives produce alterations in the genital tract, including changes in the cervical mucus, rendering it unfavorable for sperm penetration even if ovulation occurs. Changes in the endometrium may also occur, producing an unfavorable environment for implantation. Combination hormonal contraceptive drugs may alter the tubal transport of the ova through the fallopian tubes. Progestational agents may also alter sperm fertility."
So "the pill" prevents ovulation (more or less for sure), theoretically prevents implantation, and prevents sperm from even reaching the egg in some cases.
You are also correct about other medications causing problems. The FDA rates drugs into "pregnancy categories" A, B, C, D, and X. As and Bs generally have good data to support their use in pregnancy; As are "no risk whatsoever" and as such the only drugs in the category are prenatal vitamins and folic acid. B indicates strong evidence that the drug is not harmful. C says there have been no controlled studies, but risk is possible; animal studies may have shown risks. D says that risk is likely and there is evidence backing the assertion that the drug not be used in pregnancy. X is no fucking way, don't use this in pregnancy, you will screw up the baby (thalidomide, Accutane, misoprostol [a known abortifacient], alcohol, etc).
Considering that it is not always obvious that a woman is pregnant it's actually possible to do a lot of damage to a fetus that she doesn't even know is there. All three of the drug classes you mentioned contain drugs in the D and X categories. It's not just heavy-duty stuff like chemo; OTC ibuprofen can cause premature closure of the ductus arteriosus, the vessel that shunts blood so that a baby can get oxygen despite their lungs being full of fluid.
As a side note, sometimes pharmacists do need to know if you're using birth control for something other than to control birth, namely if you need to have it billed in an odd manner. Most insurance companies say one pack per 28 days; one cycle per cycle. Some people have medical reasons to skip their placebo week, in which case the pharmacy has to bill one pack per 21 days. Sometimes insurance companies require documentation that the pill is being used for, say, endometriosis instead of contraception. How legitimate you think that this practice is is up to you, but insurance companies do have a right to know what they're paying for.