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'Overdue' at 40 Weeks

Updated: Jan 17, 2023

Have you heard this phrase? Maybe you've even said it yourself. Let me tell you why I dislike the use of the word 'overdue' when it comes to pregnancy.

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What is a full term pregnancy?

According to the Mothers and Babies report from the Australian Institute of Health and Welfare (AIHW), full term gestation is acknowledged as 37 weeks and 0 days to 41 weeks and 6 days. In other words, this means that a full term pregnancy is between 37 and 42 weeks gestation. Less than 37 weeks is early or pre-term, and 42 weeks and beyond is post-term.

Does the placenta slow/stop functioning at 40 weeks?

You may have heard placental ageing or insufficiency as a reason for induction; the notion that the placenta begins to deteriorate at 40 weeks, thus being an unreliable source of oxygen & nutrients for your growing baby. However, there is no evidence of placental insufficiency being directly linked to the gestational age of the placenta to support this theory (Dr Sara Wickham).

Will your baby be too big after 40 weeks?

A very common reason to 'not pass go' is a practitioner telling you that your baby is, or will be, too big after 40 weeks. Want the truth? A baby can truly only be measured accurately after they are born. Ultrasound weight estimations can fluctuate within 15% either side of the given figure, meaning that 'for a baby estimated to weigh 4kg... a 15% margin either side means the range of the estimate is from 3400g... to 4600g' (Dr Sara Wickham).

Image by Eva Rose Birth (

There is often concern that with a larger baby, the chance of shoulder dystocia (where the shoulder gets caught behind the birthing woman's

pubic bone) increases. However, it has been shown that shoulder dystocia occurs in babies of varying weights and not just big babies, and a whopping '94% of those who weigh 4kg or more won't have shoulder dystocia' (Dr Sara Wickham). A woman's positioning and movement in birth are also key contributors in supporting a baby to navigate the pelvis. If a woman is in a reclined position, there is less of an opening in the pelvic bowl. When a woman moves into a squatting or kneeling position, or onto her hands and knees, the pelvic outlet becomes wider. Pictured is the rhombus of Michaelis protruding into the skin. Constantly shifting positions in labour so that the rhombus can move backwards allows the largest amount of space for a baby to navigate the pelvic bowl. Birth is a team effort - a woman is not on her own in birth and this is evident in that a baby actually rotates (known as cardinal movements of labour) in the pelvis to get their head and shoulders through (National Library of Medicine).


Let's go deeper

Why is the word 'overdue' correlated with 40 weeks? This word is thrown around in fear by many practitioners, yet the AIHW classifies full term pregnancy to include 40w + 13 days. Evidence also shows no indication of placental insufficiency linked with this gestational age, and you can't accurately predict the size of your baby before birth to know that they will grow too big. So why is it believed that a baby should be ready on an exact date and not a day later? Estimated Due Dates (EDDs) are estimations, not exact due dates. Yet, as a society and especially in the westernised medical culture, we have come to hold on so tightly to EDDs, that once pregnancy passes the 'date', women can often be left disappointed, feeling as though their body is failing them or they are failing their baby. I've witnessed how it negatively impacts the mental & emotional wellbeing of a pregnant woman when she has only been prepared to go to 40 weeks. In this case, that is the end goal, and anything past 40 weeks gestation isn't explained as normal.

Yet I pose the question; how can we put an exact date on Mother Nature? The same trees, planted at the same time, in the same conditions can grow at different rates and they can both be equally healthy. One may just take longer to mature. So why can't babies follow this same principle? Why are babies put on such a strict timeline before they even enter the world? I've pondered how having expectations from the word go implicates babies energetically and developmentally for the beginning of their lives. Collectively, we are projecting expectations as though we 'know better'. What if we dropped into trusting the process more, trusting that labour will begin when a baby is ready on their timeline? Babies are souls in their most pure form; unaffected by society's expectations and beliefs. What if we trusted that these souls, pure and true, know when they are ready to come earthside?

Relevant data

With reference to the Mothers and Babies reports from AIHW, induction rates have risen with the last decade (2010 to 2020) yet so have perinatal mortality rates (baby death rates) (2010 to 2020). Also, with 1 in 3 women experiencing birth trauma today (Panda Org.), I do not see logical evidence that we 'know better', only that we are interfering with the process. What we seem to have forgotten, is that women were physiologically made to birth. Unnecessary, routine interventions are not helping to improve outcomes for mothers or babies, and the statistics demonstrate this loud and clear.


This is why I (very, very strongly) dislike the phrase overdue at 40 weeks. It's not just a random opinion - the stats don't lie. I'll leave it here for now.

Please know my door is always open ~ let me know if you have any questions. If you're interested in having me as your doula for your pregnancy, birth and/or motherhood journey, reach out to me! You can see my support packages here xx


What you can do in the meantime ~

Book Recommendation

I highly recommend Dr Sara Wickham as a reputable & knowledgeable source of information. You can purchase her book In Your Own Time here if you'd like to keep diving into this topic.

Change the language.

The narratives we spread are a great place we can all start to make a difference.

Whenever I talk with a pregnant woman about her gestation, rather than asking, "How long do you have left?" I ask, "How far along are you?". This simple shift in language removes the pressure and expectation of giving birth by a certain date. If you're pregnant and people are asking you the question, you can respond with, "I'm x weeks pregnant, the baby will come when they're ready!".

When a woman reaches 40 weeks gestation, rather than being bombarded with comments, messages & calls from family and friends to say, "Think about the baby", "What if something happens?" and "Have you had the baby yet?", what if she receives encouragement, and has loved ones checking in, simply to see how she is or whether she needs anything, with no agenda? If people are overwhelming you with similar comments, let them know you'd respectfully like them to keep their concerns to themselves, and that you trust your baby will come when they're ready.


My love & warmth,


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