Morning after pill
Overview of morning after pill
The morning after pill is a form of emergency birth control. It is used to prevent a woman from becoming pregnant after she has had unprotected sex (without use of contraception, contraception failure or cases of rape). Emergency contraception is a high dosage of the birth control pill. In order to avoid pregnancy, it is recommended for use after sexual intercourse, over a period of 72 hours.
How does morning after pill work
Seldom, human conception occurs immediately after intercourse. However, it occurs several days later, after ovulation. During the period between, intercourse and conception, the sperm travels through emergency contraceptive the fallopian tube until it meets the egg.
Keeping this in view, the /morning-after pill (ECP/MAP) operates in three ways:
1. It alters the normal menstrual cycle, thereby delaying ovulation;
2. It inhibits ovulation, refraining the egg from getting released from the ovary;
3. It irritates the lining of the uterus (endometrium) and inhibits implantation.
The morning after pill as said before is a high dosage of birth control pill. The active ingredients in it are same as that of birth control pills, except in higher doses. Some of these pills contain only one hormone, levonorgestrel (Plan B, Plan B One-Step), and others contain two, progestin and estrogen. Progestin prevents the sperm from reaching the egg. Additionally, it keeps the fertilized egg from attaching to the wall of the uterus (implantation). On the other hand estrogen stops the ovaries from releasing eggs (ovulation). This prevents fertilisation and eventually pregnancy.
Side effects of morning after pill
The side effects of morning after pills are:
- Breast tenderness
- Blood clot formation
It has been observed that about 50% of women who take combined emergency contraception pills experience nausea and about 20% of them actually vomit. However, if the patient vomits within two hours after the administration of the dose, the patient is advised to repeat that dose.
These tendencies of nausea can be avoided by taking non-prescription anti-nausea medicine, meclizine. Consumption of two 25 mg tablets one hour before the administration of combined emergency contraception pills reduces the risk of nausea by 27% and vomiting by 64%. However, the administration of anti-nausea drugs doubles the risk of drowsiness to about 30%.
The levonorgestrel regimen, on the other hand has a significantly lower incidence of nausea and vomiting than the combined regimen. WHO conducted a randomized controlled trial, which showed that progestin-only emergency contraception pills are associated with an incidence of nausea 50% lower and an incidence of vomiting 70% lower than that for combined emergency contraception pills.
When to consult the physician about the side effects of morning after pill
Women who experience any of the following symptoms while taking the morning after pills should immediately consult a physician:
- Severe abdominal pain
- Severe headaches
- Eye problems, such as blurred vision
- Severe leg or arm pain or numbness
Additionally, people with severe liver disease and people with a very rare condition called porphyria should not take these pills.
Effect of morning after pill on Future Fertility
Morning after pills does not prevent future pregnancies.
Effects morning after pill on pregnancy
So far, there have been no conclusive studies of births to women who were already pregnant when they took combined emergency contraception pills. One study of 332 pregnant women who used levonorgestrel-only emergency contraception pills in the conception cycle found no increased risk of birth defects.
Moreover, two observations provide reassurance for any concern related to birth defects. Firstly, in case the emergency contraception pill fails to prevent pregnancy, it is taken long before organogenesis starts. As a result, it does not have any teratogenic effect on the pregnancy.
The FDA has removed warnings about adverse effects of combined oral contraceptives on the foetus from the package. Additionally, evidence suggests that emergency contraception pills do not increase the risk of occurrence of ectopic pregnancy.
Advantages of morning after pill
- Can be used after unprotected intercourse.
- Easy to use.
- Does not affect future fertility.
Disadvantages of morning after pill
- The pill is most effective when taken immediately after unprotected vaginal intercourse.
- Several side effects.
Effectiveness of morning after pill
According to the Society of Obstetricians and Gynaecologists of Canada (SOGC), the morning after pill prevents 95% of pregnancies when taken in the first 24 hours. However, this percentage reduces to 85% when taken 25 to 48 hours after sex. It is only 58% effective when taken between the 49th and 72nd hour.
Written by healthplus24 team
Date last modified: October 03, 2012