Once a month, we feature answers to commonly asked questions that our Valley Women’s Clinic medical staff receives. Our nurses provide answers to these questions here on the blog.
Often known as “Plan B,” the morning after pill is a large dose of oral contraceptive containing the hormone progesterone. This hormone suppresses ovulation, thickens cervical mucus, and causes some changes in the uterine lining that can prevent the implantation of a developing embryo. The effectiveness of the morning after pill depends on the time in a woman’s cycle when the pill is taken.
When a couple has intercourse, the man’s sperm is ejaculated into the woman’s vagina. The sperm swim through vaginal and cervical mucus to get into the uterus to reach the woman’s egg (if it is present) in order to fertilize the egg. If the woman’s egg has not yet been released from her ovary, there will not be a conception leading to a pregnancy.
When a woman takes the morning after pill within 24-72 hours of intercourse, her ovulation will be delayed (if it has not already occurred for that month), preventing an egg from being released into her fallopian tube and uterus. In this scenario, a possible pregnancy is prevented.
If the woman’s egg has already been released and is still viable (within 12- 24 hours after its release), then a single sperm (viable up to 5 days after intercourse) could fertilize the egg, which would rapidly develop into an embryo. The morning after pill thickens cervical mucus, which reduces the probability of a sperm reaching the egg to cause fertilization, and therefore prevents a possible pregnancy.
If fertilization occurs, the embryo moves into the uterus from the place it was fertilized (probably the fallopian tube). The embryo seeks a place to implant into the wall of the uterine cavity. The progesterone hormone changes the uterine cavity wall’s receptivity and can interfere with implantation, preventing the developing embryo from getting the nutrition it needs to survive. So this causes the embryo to die, and the woman eventually gets her period. However, her period may be delayed or she may skip that month due to the effects of the progesterone hormone on her hormonal cycle.
Some Things About Emergency Contraception to Consider:
Valley Women’s Clinic does not provide or refer for emergency contraception, but our medical staff can provide you with accurate medical information about it so that you can make an informed decision.
Keep in mind that emergency contraception is not effective if you’re already pregnant. So before you decide about using some form of emergency contraception, you may need to determine whether or not you’re already pregnant. Request an appointment with us at our Blacksburg or Radford clinic for a free pregnancy test. We also offer free STI testing for chlamydia and gonorrhea.
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