top of page
Search
Writer's pictureTheresa Pearce

Due Dates: 5 Things You Didn’t Know


As an expectant parent, the anticipation of your baby’s arrival can make your due date feel like the ultimate milestone. It is one of the first details you eagerly await at your antenatal appointments, and it quickly becomes a topic of frequent conversation with family, friends, and even strangers. You might find yourself repeating the date, "My baby will come on January 23rd, January 23rd, January 23rd," and placing immense focus on this single day. 

  

But what if your baby does not arrive on that exact date? The pressure starts to build as you approach and pass your due date, creating stress and uncertainty. Is something wrong? Should you be worried about your baby’s health or your birth plan? 

  

Let’s explore five important facts about due dates that might help ease your mind. 

  

1. Due Dates Are Often Wrong!

  

Statistics reveal that only about 5% of babies are born on their exact due date. That’s right—95% of babies arrive either before or after the due date. In fact, 10% of babies are born before their due date, while a surprising 85% are born after it. The average pregnancy lasts between 41 and 41.5 weeks, not the 40 weeks often emphasised. If most pregnancies extend beyond the due date, why do we fixate on this specific day? The undue pressure can create unnecessary stress, making the final weeks of pregnancy more daunting. 

  

2. Different Countries, Different Timelines 

  

You might assume that due dates are calculated uniformly across the globe, but that is not the case. In the UK, a pregnancy is typically considered to last 40 weeks from the first day of your last menstrual period (LMP). However, in France, the full term is considered to be 41 weeks from LMP. This one-week difference illustrates how arbitrary the due date can be. The variation in due date calculations among countries underscores that there is no universal agreement on this timeline, suggesting that there is no need to stress excessively about a single date. 

  

3. The Calculation Dates Back Over 200 Years!

  

How we calculate due dates at our first antenatal appointment has not changed for over 200 years! The calculation of due dates is still based on Naegele’s Rule, which was established by German obstetrician Franz Karl Naegele in the early 19th century! 

Here’s how due date calculation works: 

- Start with the first day of your last menstrual period (LMP). 

- Add one year. 

- Subtract three months. 

- Add seven days. 


For example, if your last period started on January 1st, adding one year, subtracting three months, and adding seven days would result in an estimated due date of October 8th. 

Exciting, you have your due date. But many mothers know they were not pregnant at the estimated time of conception. They know their cycle; they know their body. Yet the date written on your notes will not be changed. The difference is because every woman has a different menstrual cycle length. 28 days is only an average, some may have a 24day cycle and some many have a 30day cycle. Therefore, ovulation will take place at a different time, and consequently conception will too. Understanding the limitation of due date calculation is important, and it can affect how you feel when pressure starts to build closer to your due date. 


4. Your Due Date is Recalculated! 


With advancements in ultrasound technology, many parents-to-be look forward to the 12-week Dating Scan. It is an exciting milestone—likely the first time you will see your baby on screen! During this scan, you will not only learn about your baby’s development but also receive an update on your Estimated Due Date (EDD). However, it is important to remember that this date may change and is still just an estimate. 

Many parents fixate on the due date, assuming it is completely accurate because it was calculated by a machine. But even ultrasounds, which are based on foetal development, can have a margin of error of +/- 5 days. This means that your “exact” due date could be up to 10 days off! So, it is much healthier to think of your due date as a rough timeframe rather than a set-in-stone day. 


5. Why It is a Good Idea to Keep Your Due Date Vague 


After the 12-week scan, many people announce their pregnancy to friends and family, and the first question is usually, "When is your due date?" It is natural—people want to share in your excitement and imagine when the baby will arrive. 


However, as a Hypnobirthing Practitioner, I encourage you to be a little vague when sharing your due date. Why? 


As your due date approaches, well-meaning friends and family may start sending constant messages, checking in to see if you have had any contractions, twinges, or signs of labour. While they are trying to show support, it can become overwhelming, especially if you are focused on the mindset that your baby will arrive when they are ready. Their impatience can distract you from the calm, positive space you have worked so hard to create. 


This is why I recommend saying something like, "We’re expecting our baby at the end of March or early April," or "Sometime around May." Being vague helps manage everyone’s expectations—including your own! 


What’s the Evidence? 


In Hypnobirthing, we emphasise the importance of trusting that your baby will come when they are ready. This is not just wishful thinking—it is backed by science! Research published in The Journal of Clinical Investigation and Endocrinology shows that when a baby’s lungs are fully developed, they release a protein called surfactant protein-A (SP-A), which triggers labour by sending signals to the mother’s body creating an inflammatory response. This process ensures that labour begins when the baby is fully prepared to enter the world. 


Understanding this can give you peace of mind that your baby’s arrival is not dictated by an arbitrary date but by their own readiness. This mindset is especially valuable if you are faced with discussions about induction. (More on that in a future blog post—stay tuned!) 


Bottom Line...


Embrace the flexibility of your due date and focus on the joy of meeting your baby whenever that may be. It is not about a specific day—it is about the exciting journey ahead.  

17 views0 comments

Σχόλια


bottom of page