A brief biology lesson follows. Sperm can survive for up to 6 days after intercourse. An egg is released from the ovaries each month and moves into the fallopian tube. The egg remains in the fallopian tube for about 24 hours waiting for a sperm. If no sperm makes contact with the egg, the egg moves through the uterus and disintegrates. If a sperm contacts the egg and burrows into it, fertilization occurs (conception). The fertilized egg, or zygote, stays in the fallopian tube for 3-4 days, then moves through the fallopian tube to the uterus as it develops into a blastocyst. Once in the uterus, the blastocyst attaches to the uterine wall resulting in implantation. The period of time from fertilization to implantation is 9-10 days at which time the blastocyst is considered to be an embryo. By the end of the 8th week, the embryo is considered to be a fetus. By the 23-24th week, the fetus is considered to be viable, which means it has a chance of survival outside the mother.
Emergency Birth Control: Commonly known as Plan B or the Morning After Pill, levonorgestrel works in the following way: it inhibits ovulation and thickens the cervical mucus. Keeping in mind what was discussed above, that sperm can survive for up to six days and the egg remains in the fallopian tube "waiting" for sperm for about 1 day, inhibition of ovulation should stop most, but not all, pregnancies from happening. In the event that an egg is already present in the fallopian tube, or the slight chance ovulation occurs in spite of the levonorgestrel, the thickening of the cervical mucus inhibits sperm motility thereby decreasing the remaining chance of pregnancy. However, in those rare cases where fertilization occurs regardless, there is a slight chance that implantation will take place. The consensus of medical research reflects that levonorgestrel does not prevent implantation. The reason this is important is because some religious doctrine contends that life begins at fertilization, which would mean that preventing implantation could be consider abortion. While it is unlikely that emergency contraception affects implantation it is impossible to completely exclude the possibility of post-fertilization effect. Levonorgestrel is 95% effective if taken within 24 hours of intercourse. It is not effective more than 120 hours after intercourse.
Medication Abortion: “Abortion pill” is the common name for using two different medicines to end a pregnancy: mifepristone and misoprostol. First, mifepristone is administered. Pregnancy needs a hormone called progesterone to grow normally. Mifepristone blocks the body’s own progesterone, stopping the pregnancy from growing. Second, misoprostol is administered, either right away or up to 48 hours later. This medicine causes cramping and bleeding to empty the uterus. The abortion pill is very effective. The effectiveness depends on how far along the pregnancy is when the medicine is administered. For people who are 8 weeks pregnant or less, it works about 96% of the time; 8-9 weeks pregnant, about 95% of the time; and 9-10 weeks pregnant, about 92% of the time. Medication abortions can be conducted up to 70 days (10 weeks) into the pregnancy.
Abortion Statistics: 52% of abortions are performed before the 9th week of pregnancy; only 5% of abortions are performed after 16 weeks. About 7% of abortions are performed due to rape, incest or health reasons; about 93% are performed for all other reasons.
Medication Abortion: “Abortion pill” is the common name for using two different medicines to end a pregnancy: mifepristone and misoprostol. First, mifepristone is administered. Pregnancy needs a hormone called progesterone to grow normally. Mifepristone blocks the body’s own progesterone, stopping the pregnancy from growing. Second, misoprostol is administered, either right away or up to 48 hours later. This medicine causes cramping and bleeding to empty the uterus. The abortion pill is very effective. The effectiveness depends on how far along the pregnancy is when the medicine is administered. For people who are 8 weeks pregnant or less, it works about 96% of the time; 8-9 weeks pregnant, about 95% of the time; and 9-10 weeks pregnant, about 92% of the time. Medication abortions can be conducted up to 70 days (10 weeks) into the pregnancy.
Abortion Statistics: 52% of abortions are performed before the 9th week of pregnancy; only 5% of abortions are performed after 16 weeks. About 7% of abortions are performed due to rape, incest or health reasons; about 93% are performed for all other reasons.