Emergency contraceptive: How exactly does morning-after pill work?

Emeh Joy
By Emeh Joy

Basic Medical Scientist, Freelance Health Writer, Lifestyle Blogger and Business Enthusiast

Women who are not ready to have a baby should be comfortable with taking contraceptive pills. Morning-after pills work to prevent pregnancy when the regular contraceptive method fails.

Some people, especially in the African region, are still not comfortable talking about contraception; perhaps, they mistake it for abortion.

Contraception is not the same as aborting the embryo in its early stages. In fact, it prevents the fusion of the sperm cell and the ovum (egg cell) in the first place, so conception never takes place at all.

There is also that belief that if you are using a contraceptive method, that means you are having sex with who you are not intended to have sex with.

People with this mindset need to debunk that notion! This is the primary reason why most overpopulated developing countries of the world are in such miserable states.

Contraception is very much crucial for couples who are legally married as it makes for family planning. It enables you to space out your kids, and it makes it possible for the couples to prevent pregnancy when they feel they have given birth to the number of kids they can cater for.

Do you know about contraception, contraceptives and how they work?

What are contraceptives?

Contraceptives are the different birth control methods used to prevent pregnancy. There are different types of contraceptive methods ranging from hormonal methods to barrier methods.

There is also the use of IUD, implants as well as natural birth control methods. Reading about these methods in detail and also speaking with your doctor would help you and your partner decide which option to settle for.

We are here to talk about one of the 'other' methods of achieving contraception- the use of an emergency contraception pill (the morning-after pill).

How does the morning-after pill work?

Sometimes unprotected sex happens, condoms break, and the woman might miss taking her regular contraceptive pills. In the throes of passion, couples might overlook contraception until sexual intercourse is over.

Emergency contraceptives (morning-after pills) also known as Plan B has different types and comes with different brands.

This is more reason why emergency contraception pills might be needed from time to time. Morning-after pills, also known as Plan B, is useful for preventing pregnancy when sex happens unprepared.

However, it is not to be used as a replacement for conventional birth control methods or regular contraception pills.

One of the most common brand names for emergency contraception pills is 'Postinor-2'. These pills contain levonorgestrel.

"What is levonorgestrel?" one will ask.

levonorgestrel is a progestin hormone that can be used to prevent emergency contraception by delaying ovulation.

What of levonorgestrel side effects? Yes, levonorgestrel does have side effects but they are mostly mild e.g. headache, nausea, dizziness, breast tenderness. It would be best if you talk to a doctor before you start using one.

Ovulation is the monthly release of an egg cell from the ovary. It precedes menstruation (if conception doesn't occur). But if there is a sperm present at the time of ovulation, there are high chances of fertilisation taking place, and thus implantation occurs instead of menstruation.

This means instead of shedding of the lining of the uterus, the fused male and female gametes implant into the wall of the uterus after which embryonic development commences.

The chances of getting pregnant are higher if sex occurs closer to the ovulation date. The morning-after pill works by delaying the release of the egg; thus, there won't be an egg for the sperm cell to fertilise.

Note: While an egg lives for about 24 hours after release, sperm cells can live for up to 5 days, Thus conception can still occur some days after sex.

In the past, emergency contraception was thought to work by preventing implantation and was thus, termed an abortifacient, but that is wrong. It is not the same as RU-486, which is an abortion pill.

It doesn't cause abortion neither does it cause miscarriage. It also won't work if you are already pregnant.

Watch this video to understand more about how emergency contraception pills like Postinor-2 works.

How to use the levonorgestrel emergency contraceptive

It is called 'morning-after pill', but you need not wait till morning before you take the pill. You can take it immediately after sex. In fact, the faster you take the pill, the higher your chances of preventing pregnancy.

For a brand like Posinor-2, it is advised that you take one tablet as soon as possible (within 72 hours of unprotected sexual intercourse). Take a second tablet exactly 12 hours after the first tablet.

Work out a time that will enable you to take the second pill after 12 hours, and if you vomit within 2 hours of taking the tablet, consult your doctor for additional tablet.

Another way of taking emergency control pill is by the use of birth control pills. But if you are using birth control pills to achieve emergency contraception, it means you have to pop more than one pill at a time.

This approach is not that much effective and is more likely to cause nausea than levonorgestrel, but it sure does work to some extent for pregnancy prevention.

How effective are emergency pills?

The effectiveness of emergency pills depends much on how early they are taken. For instance, for a tablet such as Postinor-2, if taken within 24 hours has up to 90% chance of preventing pregnancy. If taken after 48-72 hours, the chance reduces to 58%.

Levonorgestrel morning-after pills work to prevent release of egg from the ova thus fertilization of egg cell by sperm cell cannot occur.

It is not known whether it will still be effective if taken after 72 hours. However, you should know that the emergency pill is not as effective as regular contraception. Hence, it would be best if you didn't take it as a form of birth control.

You and your spouse should not opt for it as a routine pregnancy preventive method. Instead, think of it as a backup -explains why it is called, Plan B.

Note: Plan B won't prevent you from getting pregnant if you have unprotected sex after taking it. You take it right after unprotected sex for contraception.

Also, factors like being obese can affect its effectiveness. While obesity doesn't render it ineffective, it reduces its effectiveness. Again, certain medications like drugs for HIV, tuberculosis and epilepsy can interact with the pill and make it less effective.

Will an emergency contraception pill prevent pregnancy during ovulation?

So we talked about emergency contraception pill preventing pregnancy by preventing or delaying ovulation. But what if you are ovulating already before taking this drug?

Many questions have arisen as regards the use of morning-after pills during ovulation such as, "how effective is the morning after pill after ovulation?" "does the morning after pill work if you are ovulating?" "how does Postinor 2 work during ovulation?" etc.

Perhaps, this is one of the shortcomings of morning-after pills. It is also one of the reasons why it doesn't offer protection as much as regular contraception pills.

Emergency contraceptive pills like Postinor-2 work to delay or prevent ovulation thus, if taken while one is already ovulating, it might not prevent pregnancy.

Emergency pills work with timing. If sexual intercourse takes place while you are already ovulating, you are much likely to get pregnant as it can't stop ovulation at that point.

Who shouldn't take emergency contraceptive pills?

While it is advisable to take the morning-after pill in emergency cases, certain people are discouraged from taking it mostly for health concerns.

  • Pregnant women or women who suspect they are pregnant shouldn't take it.
  • Don't take it if you have a history of allergy or hypersensitivity to its ingredients.
  • If you are experiencing abnormal vaginal bleeding, do not take the pills until you have seen a doctor.

Are emergency contraceptive pills safe?

As regards the safety of use, there have been no reported cases of death or serious health complications with the intake of morning-after pills.

It is safe to use while breastfeeding, as well. It isn't toxic provided it is taken in the right dosage and as directed.

Side effects of emergency contraceptive pills

Even though emergency contraceptive pills are relatively safe to use, just like other drugs, they have mild side effects. They have side effects similar to that of the regular contraceptive.

Here are some side effects of morning-after pills:

  • Nausea
  • fatigue
  • abdominal pain
  • headache
  • breast tenderness
  • changes or delay with the menstrual cycle
  • vomiting

Couples are advised to practise family planning. In countries like Nigeria, people are given the freedom to give birth to as many as they can, and that freedom seems like it's being abused.

It has been a matter of concern that even the Director-General of the National Agency for Food and Drug Administration Agency (NAFDAC), Prof Mojisola Adedeye urged Nigerians to practise family planning.

Morning-after pills can go a long way to help prevent conception as it serves as a backup plan when the conventional birth control method fails or wasn't properly used.