Most women will have heard of “emergency contraceptive pills” but many may still not know exactly how they differ from regular birth control pills, how to use them or what their side effects are. So, let’s find out more.

What are emergency contraceptive pills?

Emergency contraceptive pills are high-dose hormonal pills that are taken orally to prevent pregnancy after “emergency sex”, meaning sex without contraception, or failure of contraception such as condom tearing, forgetting to take two or more regularly-taken birth control pills, and non-consensual sex.

Emergency contraceptive pills should only be used when there is an emergency. They should not be taken in place of other oral contraceptive pills. All birth control pills already contain high amounts of hormones, so any excess can cause adverse effects. Moreover, emergency contraceptive pills are less effective than regular birth control pills.

Types of emergency contraceptive pills

Emergency contraceptive pills comprise three types:

·       Combined hormonal type – The active ingredients are estrogen and progestin hormones.

·       Progestin-only emergency contraceptive pills – These are the emergency contraceptive pills most commonly used in Thailand.

·       Emergency contraceptive pills containing ‘antiprogestin’.

Mechanism of emergency contraceptive pills

After intercourse, sperm can survive in the reproductive tract for up to five days. If the egg is ovulated within these five days, the sperm can fertilize the egg and cause pregnancy. Emergency contraceptive pills interfere with, inhibit or delay ovulation by creating mucus at the cervix that makes it more difficult for sperm to combine with an egg. However, emergency contraceptives have no effect on any fertilization that has already taken place. In other words, if a woman is already pregnant, emergency contraceptive pills cannot terminate the pregnancy.

In most emergency contraceptive pills, ‘levonorgestrel’ interferes with ovulation by inhibiting the pre-ovulation peak of luteinizing hormone (LH). This in turn inhibits the growth or rupture of the egg sac and causes corpus luteum, a group of cells that produce progesterone, not to function. This is an important and highly effective mechanism for preventing pregnancy as the hormone progesterone directly affects the growth of the uterine lining where the embryo is implanted.

Side effects of emergency contraceptive pills you should know before taking

As emergency contraceptive pills are high hormone dosages, they may have any of the following side effects:

·       Feeling sick for a short time with dizziness, fatigue, headache, abdominal pain, breast pain, etc. If these symptoms persist for several days, you should consult a doctor.

·       Menstrual periods may come irregularly, for example, coming spontaneously, late, or early. If your period is seven days late, you should take a pregnancy test.

·       Taking emergency contraceptive pills too often can cause hormonal imbalance which may increase the risk of an ectopic pregnancy (when a fertilized egg implants itself outside the womb).

·       Studies have shown that emergency contraceptive pills can cause calcium deficiency leading to osteoporosis.

Factors necessitating using emergency contraceptive pills

·       Having unprotected sex

·       Having non-consensual sex

·       Failure of birth control method such as a condom being torn, dislodged or improperly applied or leaking

·       Forgetting to take a regular contraceptive pill, as follows:

o   Missing taking three or more combined hormone type pills, or

o   Missing taking a single progestin hormone type pill more than three hours after the regular time of taking them or more than 27 hours after the previous pill, or

o   In the case of pills containing desogestrel (0.75 mg), missing taking a pill more than 12 hours after the usual time or more than 36 hours after the previous pill.

·       Missing scheduled contraceptive injection:

o   With Norethisterone Enanthate (NET-EN), missing injections for more than 2 weeks

o   With Depot-medroxyprogesterone Aacetate (DMPA), missing injections for more than 4 weeks

o   With Combined Injectable Contraceptive (CIC), missing injections for more than 7 days

·       Loose diaphragm or cervical cap or tearing or breakage before removal.

·       Failure to ejaculate outside the sex organs, whether vaginal ejaculation or external genitalia.

·       Mistaken calculation of a ‘safe’ intercourse day or an intrauterine device (IUD) contraceptive implant falling off.

How to take emergency contraceptive pills

Emergency contraceptive pills available in Thailand come in a box. Each box contains 1 blister. Each blister contains 2 pills. Each pill contains a high-dose (750 micrograms per pill) of levonorgestrel hormone. Take the first pill as soon as possible after unprotected intercourse, not exceeding 72 hours. Take the second pill no later than 12 hours after the first pill. If vomiting occurs within 2 hours of taking each pill, new medication should be taken. It is not recommended to take more than 4 pills, or 2 blisters, in 1 month.

Taking the first pill within 72 hours of intercourse followed by a second pill is 75% effective in preventing pregnancy. Taking the first pill within 24 hours increases the effectiveness to 85%.

It is also possible to take both emergency contraceptive pill dosages at the same time. Efficacy and safety are similar to when the dosages are taken separately. This applies to double dosage emergency contraceptive pills containing 1.5 mg of levonorgestrel per tablet. Taking a single dose may be more convenient than dividing the dosage. However, some women may experience nausea and vomiting from taking a single high dose rather than two smaller doses.

Factors affecting the efficacy of emergency contraceptive pills

·       Delay in starting medication

As already mentioned, the effectiveness of emergency contraceptive pills is reduced if they are taken 72 hours or more after unprotected intercourse and they may not work at all if taken 96 hours or over. Delay in taking the second pill has a similar effect.

·       Body Mass Index (BMI)

Being overweight, or having a body mass index of from 25 kg / square meters to 30 kg / square meters, or being obese with a body mass index of 30 kg / square meters or more, will result in lower levels of levonorgestrel than those who are not obese. Some reports indicate that women with a high body mass index who use emergency contraceptive pills have higher pregnancy rates than those who are not obese.

·       Drugs that induce liver enzymes

These drugs increase the activity of enzymes that convert the drugs, to the point of reducing their effectiveness.

Who shouldn’t use emergency contraceptive pills?

Those with the following diseases or conditions should not use emergency contraceptive pills:

·       Women with cancer of internal organs, including breast cancer

·       Those with acute liver disease, cirrhosis or liver cancer

·       Those who have or have had a cardiovascular disease

·       Those with high blood pressure

·       Those with thromboembolic disease

·       Those with epilepsy who take anticonvulsants

·       Diabetics with renal dysfunction or abnormal blood vessels

·       Those over 35 years old, heavy smokers, obese or having high cholesterol

·       Those with migraine with aura

Misconceptions about emergency contraceptive pills

·       “Emergency contraceptive pills can be used as abortion pills.”

Emergency contraceptive pills cannot terminate an existing pregnancy.

·       “Emergency contraceptive pills can be used to prevent sexually transmitted diseases.”

Emergency contraceptives do not protect you against communicable diseases. Condoms should be worn to protect against sexually transmitted diseases.

·       “Emergency contraceptive pills can cause fetal abnormalities.”

If emergency contraceptive pills are taken by a woman who doesn’t know she is pregnant, the drug will not deform the fetus. There are no reports of infants born with disabilities whose mothers took emergency contraceptive pills without realising they were pregnant.

·       “Emergency contraceptive pills can be used consecutively in place of regular oral contraceptive pills.”

Emergency contraceptive pills should not be used continuously for an extended period of time as their effectiveness is less than that of regular contraceptive pills.

·       “Taking emergency contraceptive pills potentially affects your next pregnancy and ability to get pregnant.”

Emergency contraceptive pills pose no danger to any forthcoming pregnancy and do not make it more difficult to get pregnant.

·       “Emergency contraceptive pills are 100% effective in preventing pregnancy.”

Emergency contraceptive pills do not provide 100% protection against pregnancy.

Emergency contraceptive pills are more available than some of us realize. Understanding and knowing how to take them properly and safely is something every woman of child-bearing age should know about so they can stay in control of pregnancy and live worry-free.

Krungthai-AXA Life Insurance customers interested in health care can check out other articles at https://www.krungthai-axa.co.th/th/health-advisories.

References

·       Ramkhamhaeng Hospital
https://www.ram-hosp.co.th/news_detail/648

·       Paolo Hospital
https://bit.ly/3WOcf41

·       Samitivej Hospital
https://bit.ly/3GmJynw

·       Phyathai Hospital
https://bit.ly/3ih8qVT

·       Faculty of Pharmacy, Mahidol University
https://bit.ly/3vCVLzM
https://bit.ly/3vCVSLI
https://bit.ly/3Cn3CoM

·       Pobpad website
https://bit.ly/3jVV8yN
http://bit.ly/3DcDugG