When we become pregnant one of the first burning questions we have is “what is my due date?”

Our due date has this magical quality because it symbolises the day that we become a mother, whether it’s the first time or to a new little one. The thing is, because the date carries such meaning to us, we hang everything on it, and rightly so. We start planning, things like…

  • when to give up work
  • when to have the baby shower
  • when to start preparing the nursery
  • when our partner should schedule time off work
  • when to move house by (if moving is a requirement of having an extra member in the family)

Now looking at this list, it’s easy to see why this date is such a big friggin’ deal… SO MUCH HANGS ON IT!

And yet, your due date is probably wrong (I’ll tell you why in a bit).

due date

Now those in the know will step in here saying “it’s a due MONTH not a due DATE” and they’re absolutely right. But talking to your healthcare providers about a DUE MONTH is going to be pretty tricky when they’re pressuring you for an induction. They’re far more comfortable talking actual dates.

And when the time comes for the “induction conversation”, which it will do as your approach your due date, you need to be super confident in your due date if you’re going to resist the pressure and fear-based messages that you will no doubt be faced with.

So this is why it’s important for you to have confidence in your due date. But the problem is, it’s very likely that your due date is pretty flakey.

Let me tell you why.

1. It’s based on an idea in the Bible

Yes, I kid you not! The most widely used due date calculation method, Naegele’s Rule is based upon evidence in the Bible that human gestation lasts approximately 10 lunar months. Indeed. It’s not based on science or research, but on evidence from the Bible.

Now I don’t know about you, but I would prefer to base the arrival of my little one on something a little bit more concrete and recent than something from the Bible. It’s not as if we haven’t had any pregnancies and births since then to measure!

There are other due date calculation methods that exist that are based on science and research, but these tend not to be used. Crazy I know!

2. Your unique ovulation cycle wasn’t considered

Now, if you were asked at your first midwife appoint what your ovulation cycle was, then brilliant news, it’s probably been taken into account. But even if you were asked – do you actually KNOW your ovulation cycle. Some women know this.. perhaps they’ve been trying to conceive and so this is information that is known to them. But often we don’t. Knowing your ovulation cycle requires you to be measuring your menstrual cycle for a while (to take into account of life stresses and allowing for our body to adapt after stopping the pill for example).

3. Your period length was not taken into account.

As with your ovulation cycle, it’s unlikely that you were asked this information. And even if you were, is this something that you know?

“But I gave the date of my last period!”

You were probably asked the first date of your last period (LMP), but to take this information in isolation without your ovulation cycle and length of your typical menstrual cycle, just adds to the inaccuracy. In absence of accurate menstrual information caregivers will likely assume that your menstrual cycle is 28 days and that you ovulate halfway through your cycle (on day 14). But menstrual cycles can vary in length from 25 to 37 days. And, ovulation doesn’t always happen halfway through a cycle; if you’re stressed or recently off the pill then you won’t. So depending on the finer details of your menstrual cycle, your due date could be up to a week or more out… and that’s before we look at the fact that the method used to calculate your EDD is not even a sensible one!

What can I do?

  • Speak to your midwife or birthing care provider to understand what they based your due date on.
  • Ask them if they took into account the length of your menstrual cycle and your ovulation cycle.
  • Ask them which due date calculation method they used.

So, what IS my due date?

If you’d like to calculate your due date using some calculation methods based on science and research, I’ve created a DUE DATE CALCULATION CHEAT SHEET to help you.

My cheat sheet includes 3 additional calculation methods so that you can have a better understanding of your due date and how realistic it actually is. Of course, when the time comes, it’s all down to your baby and when your baby is ready. But, if you find yourself going past your due date and facing the pressure to be induced, wouldn’t be helpful to have more confidence in the date that your baby is likely to make an appearance by?

When you sign up you will also receive emails to help you feel calm and confident as you prepare for your birth.

DUE DATE CHEAT SHEET – Find out a more realistic due date HERE

If you’d like to find out more about due dates, you might fancy listening to this podcast episode: Your due date is wrong.

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