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The morning after (emergency birth control)

What is emergency birth control?

Emergency birth control (or emergency contraception aka “morning after”) helps prevents pregnancy after you have had unprotected sex or if the birth control method that you used failed (e.g. condom split).

What are the different types of emergency contraception?
  • Morning after pill

There are 2 different morning after pills: ellaOne and Postinor-2.

ellaOne has 1 tablet that should be taken as soon as possible within 120 hours (5 days) after sex. It is up to 98% successful if taken correctly. Its effectiveness drops after 120 hours from sex.

Postinor-2 has 2 tablets – the first should be taken as soon as possible within 72 hours after sex and the second should be taken 12 hours after the first tablet. It has a 85% effectiveness in preventing pregnancy, but this is time dependent. If the first tablet is taken within 24 hours after sex, it is 95% effective. If it is taken between 48 to 72 hours after sex, it is 58% effective. 

Vomiting is a side effect of the morning after pill and you should take another tablet as replacement and see your doctor if another dose is needed. Other side effects include headache, breast tenderness, dizziness or fatigue. 

There are certain medications that can reduce its effectiveness e.g. medicines for epilepsy, tuberculosis, acid reflux.

If you have another episode of unprotected sex after taking the morning after pill, the pill will not stop you from becoming pregnant.

  • Copper T (IUD)

This small T-shaped device that is put into the uterus. It should be inserted as soon as possible within 120 hours (5 days) after sex, or up to 5 days after the earliest time you may have ovulated. This can be done in the clinic. It is more effective than the morning after pill in preventing pregnancy (99% success), and can be left in to be used as your regular birth control method.

Important notes

  • Emergency contraception does not work if you are already pregnant
  • Morning after pills should not be used as your regular method of birth control
  • Emergency contraception does not protect you against sexually transmitted infections (STIs)
  • Although it is common for your next period to be a few days late, you should do a pregnancy test anytime you suspect you may be pregnant and see your gynaecologist

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Dr. Ng Kai Lyn

MBBS (SG) | MMed (SG) | MRCOG (UK) | FAMS (SG)

Empowering Women's Health

This article has been medically reviewed by Dr Ng Kai Lyn
Dr Ng Kai Lyn 黄楷伶 is a Consultant Obstetrician and Gynaecologist with sub-specialty expertise in urogynaecology and minimally invasive surgery, as well as a clinical interest in fertility.
(65) 9152 4942
(65) 6635 2100
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