Gestation Calculator

This calculator has been designed to give you an idea of the treatment options available to you*. If you decide to have an abortion with Marie Stopes UK, one of our nurses will give a more approximate gestation date during your appointment by way of a scan.
*Please note that this online calculator will only give you an estimated gestation based on the details you have provided.

Please select the first day of your last menstrual period.



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Call us now on 0345 300 8090 or email services@mariestopes.org.uk

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What are the risks and side effects of a medical abortion?

Medical abortion is a very safe option for termination of early pregnancy. However, as with any medical treatment, it is not free from possible complications or risks.

Side effects of medical abortion

  • nausea or vomiting
  • headaches 
  • diarrhoea
  • fever, chills, temporary flushes or sweats

Possible complications and risks of the medical abortion*

Incomplete abortion – (less than 5 in 100 people)

This means that the pregnancy is no longer developing, but some of the tissue is left in the womb. This can cause pain and bleeding, and may lead to infection. If incomplete abortion is diagnosed, further treatment such as medical (misoprostol) or surgical treatment will be discussed.

If the medical abortion tablets are given at the same time, this risk increases slightly to 5 in 100 people. 

Treatment failure (continuing pregnancy) – uncommon (1 in 100 people)

This means that the pregnancy continues to develop, even after taking both sets of tablets. In the event of continuing pregnancy further treatment, such as medical (misoprostol) or surgical treatment will be discussed, or transfer to another service can be arranged. We recommend doing a pregnancy test 3 weeks after treatment (any earlier test will not be reliable). 

If the medical abortion tablets are given at the same time, this risk increases slightly to 2 in 100 people. 

Infection – uncommon (less than 1 in 100 people)

This can be reduced by following our aftercare advice. If an infection is not treated it can lead to further serious problems and future infertility.  If you have symptoms of pelvic inflammatory disease (PID), such as unusual vaginal discharge, fever, or pain and discomfort in the lower abdomen you must seek urgent medical attention. See your GP or visit your local A&E department.

Haemorrhage – very rare for a medical abortion (less than 1 in 1000)

If you experience bleeding that is soaking through more than 2 sanitary pads an hour you should seek urgent medical advice. 

Serious complications have warning signs

If you experience any of the symptoms below call us straight away: 

  • Very heavy bleeding that soaks through more than 2 sanitary pads (suitable for a heavy flow) an hour
  • Abdominal pain or discomfort that is not helped by pain relief medication, or by heat pad
  • Vaginal discharge that smells unpleasant
  • Fever lasting more than 24 hours

Please keep in mind…

Not everyone will be suitable for medical abortion treatment. However, they may still be suitable for a surgical abortion. During your consultation we will discuss your medical history to make sure the option is safe for you.

If you have any questions about treatment suitability, you can call us any time.

Need to talk about your options?

Our caring, specialist staff are on hand 24/7 to offer expert advice and support – from your initial consultation to treatment aftercare. 

Call us now on 0345 300 8090 or email services@mariestopes.org.uk

* Risk statistics taken from Marie Stopes UK data, 1 January 2016 to 31 December 2016 or from the Royal College of Obstetricians & Gynaecologists, 2011. The Care of Women Requesting Induced Abortion: Evidence-based Clinical Guideline Number 7