Supporting you, Campaigning for all
• Campaigning for better births for all
• Protecting human rights in childbirth
• Independent information about pregnancy and birth
• Raising awareness of research

For a better birth

Latest Content

Journal

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Just ‘birth’: the phenomenon of bir…

AIMS Journal, 2023, Vol 35, No 4 Editor’s note: AIMS is honoured to present Mariamni’s research study in which she interviews 10 women who gave birth without a healthcare…

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An interview with Dr Rebecca Moore…

AIMS Journal, 2023, Vol 35, No 4 Interview by Alex Smith Hello Rebecca, thank you for agreeing to answer some questions about your work with Make Birth Better. I wonder i…

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Postpartum: A short story

AIMS Journal, 2023, Vol 35, No 4 Editor’s note: This is a fictional account of the state of mind of a mother suffering postnatal illness. As such, it is a powerful and di…

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Events

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The Foundation Stones for Supportin…

‘The Foundation Stones for Supporting the Physiological Process in Pregnancy and Birth’ is led by Alex Smith (AIMS Journal Editor and Helpline volunteer) supported by Deb…

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AIMS Workshop: Focus on Resolution

Join us for the an interactive online AIMS workshop " Focus on Resolution " with Dr Rebecca Moore . Rebecca who is a Consultant Psychiatrist and founding member of Make B…

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Next steps for NICE in England

This conference will discuss next steps for NICE in delivering innovation and supporting clinical practice in health and social care in England. It is bringing stakeholde…

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Latest Campaigns

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BICS Conference poster: AIMS Campai…

AIMS Campaigns Team volunteers are presenting a poster about our campaign for Physiology-Informed Maternity Services at the 2023 conference of the British Intrapartum Car…

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Review: National Cohort study on in…

This is a review of the paper (https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1004259%20 ) published on July 20, 2023 by researchers at St George’…

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SWEPIS – The Swedish Post-term Indu…

The evidence on whether there is a benefit in inducing labour if a pregnancy would otherwise last beyond 41 or 42 weeks is far from clear. 1 The SWEPIS study 2 , publishe…

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Pregnancy Calculator i

When's your due date?

What does your "due date" mean? How long is a normal pregnancy? How might being given a due date affect you and your baby? Enter the first day of your last period to discover when you're most likely to give birth.... and to find out more about due dates, induction and "post date" babies.
You are weeks pregnant.
Date of the first day of your last period
Adjusted cycle length

Date of the first day of your last period

The date of your last period allows an estimation of when you ovulated and conceived your baby.

A surprising number of women will have a bleed after they are pregnant, and although seeking advice from a doctor or midwife is recommended, usually this bleeding is not a problem.

Adjusted cycle length

Your menstrual cycle is counted from the first day of one period to the first day of the next. The average menstrual cycle is 28 days long, but many women will have longer or shorter cycles than this.

Ovulation usually takes place about 14 days before the next period. This means in a short cycle ovulation will be less than 14 days after your last period and with a long cycle more than 14 days after your last period. Giving the length of the cycle allows this to be taken into account in calculating your due date.

Many women have irregular cycles which make using the last day of their period less reliable for estimating due date.