The Money Blog

Lorem ipsum dolor sit amet, metus at rhoncus dapibus, habitasse vitae cubilia odio sed. Mauris pellentesque eget lorem malesuada wisi nec, nullam mus. Mauris vel mauris. Orci fusce ipsum faucibus scelerisque.

The Due Date Myth

Dec 16, 2023

“When are you due?”

Your friends and family ask? And magically somehow we have a date our baby is supposed to be born.

As much as we would like it to be so, this date is not based on evidence or on reality.

Curious to know how we have come to the due date calculation? It is with a rule created by German obstetrician Naegele in 1812, using the average gestation of 280 days. To use it: we add 7 days to the women’s last menstrual period, add a year and then deduct three months. This rule relies on the woman having a 28 day cycle and ovulating on day 14, which we know is not a given for all women.

This means that for those women who ovulated later in their cycle or have longer cycles naturally, they are being given early “due dates” and then pressured into induction as that date approaches. Natural birth advocates call this so-called due date, a “guess date”, and I often encourage women to provide a due month or season to friends and family to take the pressure off as their birthing time approaches.

If choosing to have medical support during pregnancy, you will be offered something called a dating scan early in pregnancy where you will be provided with another estimate based on baby’s size. It is worth investigating whether this feels necessary for you when we know there are risks of ultrasounds, particularly in early pregnancy (link to blog post on that here).

Again, it can be normal for different babies to be different sizes (just as we humans are all different sizes), and size isn’t necessarily an indicator of baby’s gestation. It can be useful before you conceive to track your cycle using the fertility awareness method so you can work out your own guess date rather than relying on external sources, but even then take it with a pinch of salt.

We are not robots

Most babies arrives between 37-42 weeks and each woman has her own gestation, with some babies born at 35/36 weeks seemingly at term and others born at 40 weeks seemingly premature. Some women gestate their babies for up to 44 weeks. Can we respect that women’s bodies are individual and unique, and that each baby is individual and unique? We are not robots, we are mammals.

For those babies due to be born at 41/42/43 or even 44 weeks, it could be premature for them to be delivered by induction before then. Can we consider that our babies might know precisely right time to be born? Can we give them the honour of choosing their birth day as it is meant?

What does the evidence say?

And then there is the evidence for induction or not going beyond a certain set of dates. How do the benefits of this compare to the risks? Ask your care provider for the research and reflect on this. I have attached the NHS guidelines below (but note this is essentially induction at 41 weeks vs. induction at 42 weeks rather than full expectant management).

For most women, their main concern is stillbirth (something medical staff throw about more than we would like), and the NHS guidelines show that past 41 weeks the risk is 1-2 in 1000 (0.16%) whilst inducing at 41 weeks the risk is less than 1 in 1000 (0.07%). However looking at these numbers we can see that the risk is still very low, and many other studies show perinatal mortality is at it’s lowest after 42+ weeks (AIMS article here with all the research).

What does induction actually involve?

What we must consider is what induction involves and how it often looks for women, it is a medical intervention which your body is not prepared for. Birth is partly still a mystery to us, but it is thought that when the birthing time is approaching, oxytocin receptors appear on the uterus and an increase of oxytocin to these receptors starts the birth process. If enough of these receptors have not yet made an appearance, synthetic oxytocin will struggle to impact the birth process (leading to a “failed induction” and then an “emergency” caesarean.

We also know that synthetic oxytocin does not have the same impact on the body as natural oxytocin as it cannot pass through the blood brain barrier, so your body receives the message that oxytocin is present but your brain does not. This is thought to impact mother/baby bonding as the hormone is missing from the brain at this vital time. Synthetic oxytocin also stimulates artificial, potentially stronger contractions resulting in more discomfort for the mother. As she is out of the home and without her usual comfort measures, she may choose to have medical pain relief (each having their own risks), including epidural which in turn limits mobility, a hugely important part of the birth process.

In addition to synthetic oxytocin, care providers will also potentially offer prostaglandin gel/Foley’s balloon to encourage cervical ripening and dilation. Each woman’s body respond differently to this. It is an artificial intervention rather than the natural birth process our bodies have been designed to do over the generations of women that have given birth before us.

What does your intuition tell you?

Of course, it is to each woman to decide what feels right for her. I work with women to connect with their intuition and explore this. For some they have concerns about the wellbeing of their baby and so induction or medicalisation may feel like the right route, but this isn’t a given and it’s important for us to question whether interventions should be given as a routine procedure.

Some questions to reflect on:

Can we trust in the wisdom of our bodies to birth at the time that is chosen by our babies?

Can we be patient in pregnancy as we will need to be in motherhood?

Can we manage our discomfort in late pregnancy as we will in the birth process?

If your birthing time approaching and you could use some support, you can schedule a complimentary consultation with me here.