Fixed point due dates and wider windows

If Doctor Who turned up in front of you right now and offered you the chance to go elsewhere in time to change, remove or amend one tenet of modern maternity care, what would you choose?

Even though I understand that the ripples would ripple out to affect other elements of the cosmos in unforeseen ways and all that, I know what I would pick. I would REALLY like to spend a day in an alternate universe which didn’t entertain the idea that it is useful to spend a couple of minutes at the beginning of pregnancy using a whirly wheel, app or other calculator to calculate an estimated date of birth which is then used as a reference point for the next two hundred and eighty or so days.


What’s the problem here?

In Your Own Time was written to help parents and professionals better understand the issues and the evidence relating to the current induction epidemic. Looks at the evidence relating to due dates, ‘post-term’, older and larger women, suspected big babies, maternal race and more.

The guesstimated due date calculation leads to grief and anguish for so many people.

Having a fixed point due date can cause women to feel desperate as it looms and passes without the arrival of their baby.

Fixed point due dates can lead to well-intentioned pressure from worried (and excited) families.

And they lead to more intervention than some might consider necessary.

Some women abandon all of their previous desires in the face of the pressure.

That isn’t necessarily problematic in itself but I know from experience that a proportion of these women later regret not awaiting spontaneous labour.

All of this might be more justifiable if the setting of a fixed point due date were based on sound reasoning. However, as with so many aspects of maternity care, it is not built upon a solid foundation of evidence and can be challenged in many ways.

I have discussed the evidence in this area elsewhere, but today I would like to focus on explaining what I see as the problem of fixed point expectation syndrome. (Yes, I made that up).


Fixed Point Expectation Syndrome

parcelI use the term fixed point expectation syndrome to describe a human state that we can enter anytime we have been looking forward to something.

Like, for example, the arrival of something exciting that one has ordered online.

Or when we are waiting for news about whether we’re going to be offered an exciting new job.

Consciously or subconsciously, we create a fixed point in our minds which represents the time and/or date on which we think the thing we are anticipating – in this case the arrival of the parcel or the news of the job decision – should occur. When it doesn’t arrive on time, we often experience negative feelings.

This is all a very natural and understandable human process, by the way, and no judgement or blame is intended. Estimated dates are seen as necessary if we are to organise our lives within the context of modern culture. No-one wants to take the whole week off to await their new patio furniture. And if no-one had a due date, midwives would find it much harder to organise their lives.

But it’s still an issue worth considering. The fixed point deadline we have created in our mind may or may not be a reasonable assessment of the likely timescale but, either way, there is a problem.

The problem is called variability.

The world we live in is uncertain and things vary. In a percentage of cases the estimated arrival date will be met or exceeded and the person will be happy. In other cases, the deadline will pass without the event having occurred. That’s normal. But many people don’t like it when they end up on what they see as the ‘wrong’ side of the normal range. The result of a fixed point expectation not being met can range from minor disappointment and the need to make an adjustment in planning your evening around the non-arrival of your new book or job offer to more major upset.


And when it’s a baby, not a book?!

Now magnify the excitingness of the parcel by a million, give a delivery estimate that is several months away and see how much fixed point expectation ensues.

This is exactly what we do when we use a ‘due date’ to mark when we think birth might happen. No matter whether the woman herself or a health professional does the calculating, a percentage of women and their families are going to need to work really hard to adjust their thinking when the due date passes without even the first sign of a nesting urge.

Normality has a range.

Because pregnancy lasts for nine or ten months, the estimate can be out by two or three weeks for a good number of people. And, in a culture which promotes fixed point expectation syndrome, this has knock-on effects. In the worst-case scenario, it can lead to decisions which are out-of-sync with what the individual might have chosen in a less emotive and disappointed state. These are the kind of decisions that people may come to regret. This is why I would like to see what life – and birth –

Sara Wickham’s bestselling book explains the process of induction of labour and shares information from research studies, debates and women’s, midwives’ and doctors’ experiences to help women and families become more informed and make the decision that is right for them.

would be like in an alternate universe in which it had never occurred to anyone to calculate a fixed point due date.

Yet I don’t think we have to give up hope.


What could we do?

I believe that there is one thing that we could all easily do that would make a huge difference, even in a universe that seems to almost revolve around fixed point due dates.

We can accept that these are still going to be a reality and simultaneously embrace and share the notion of a wider window which offers a more realistic perception of when a baby will arrive.

If we can help people to understand the degree of uncertainty involved in estimating such an event from such a long way off, and spread the idea that it is better to view this as a range rather than a fixed point, then I think we can help them not to experience fixed point expectation syndrome.


What are the downsides of our focus on having a due date?

I have long written about how I think the act of calculating and then focusing on an estimated due date is problematic. It is problematic because this one date becomes a much-anticipated fixed point. When it then passes before the arrival of a baby, as it inevitably will for a good proportion of women, the expectations that have been built around this can lead to difficult feelings, decisions and/or situations.

It would be unrealistic, however, to suggest the eradication of the fixed point due date. (I am, however, still very much open to my trip in the TARDIS to visit any universe where this notion has never occurred to anyone).

Instead, I propose that, alongside whatever we do right now, we open discussions about wider windows with women, families, colleagues and everybody else.

In Your Own Time was written to help parents and professionals better understand the issues and the evidence relating to the current induction epidemic. Looks at the evidence relating to due dates, ‘post-term’, older and larger women, suspected big babies, maternal race and more.

This problem is not limited to the confines of the antenatal clinic.

Discussion of due dates permeates every corner of modern society.


Normality has a range

The notion of substituting a wider range of probable birthing time for the current fixed point due date isn’t new. In a classic article, midwife Brenda van der Kooy (1994: 5) noted that, “as elsewhere in nature, normality has a range”. Stickler (1994: 325) also recommended using “less specific terminology such as ‘month of expected delivery’ … [which] would cure the many ills stemming from the pseudoaccuracy of the EDC”.

Until I began carrying out research into this, however, I hadn’t found any studies which demonstrated midwives or any other practitioners using these ideas in everyday practice.  (If you want to read more about my research, you might like Post-term pregnancy: the problem of the boundaries or Stretching the fabric: from technocratic normal limits to holistic midwives’ negotiations of normalcy.)


Stretching the Fabric

As one of the article titles above implies, the concept of stretching the fabric was important to the midwives in this research. In fact, this phrase was used by one of the midwives. She said “I like to stretch the fabric of what is normal…”  Several of these midwives described how they ‘widened the window’ to encompass a week or (more often) a month rather than a single date.

 I always talk to them about having a due month, and, you know, if that is like the beginning to the end of a month or a whole, you know the middle of a month to the next.  (Xena)

 [I tell women] a lot that the date is not a set date, that it’s actually a whole month that the baby can be born in. If [the fixed point due date is] June 16th she should be ready between the 1st and the 30th of June, anytime. (Anna Andhra)


Sara Wickham’s bestselling book explains the process of induction of labour and shares information from research studies, debates and women’s, midwives’ and doctors’ experiences to help women and families become more informed and make the decision that is right for them.

What can we learn?

This is not unique. I am aware that a number of midwives like to mention the idea of a range, or at least note that the fixed point due date is not very reliable. The midwives in my research went quite a bit further than this, in three ways. And I think we can learn something from what they did.

1. Their discussions were ongoing.  The proposing of a wider window is not something they did during the initial reckoning of the due date and then forgot about. The notion of the wider window is emphasised and discussed throughout pregnancy, which was considered as a journey. In other words, they offered continual reminders. I imagine that the women whose pregnancies were longer than average were less disappointed than they might otherwise have been as a result.

2. They explained their rationale.  The midwives’ discussion of the wider window wasn’t some kind of secret incantation that was uttered in the hope that it would have some magical effect in reducing the risk of fixed point expectation syndrome. They were open and honest about it. They explained that they saw it as part of their role to help women move away from the absolute nature of the fixed point due date and towards a more flexible approach. The midwives’ rationale for doing this is linked to what they perceive to be the potentially stressful impact that a fixed due date can have on the woman, especially where this is perceived as an appointment (Davies 2003) which for many women will pass without any sign of labour.

3. They didn’t just talk to women. They understood only too well that pressure (often well intentioned and loving in nature) came from the woman’s family. So they took every opportunity to mention the fact that we need to think of this time as a window. Often, they described making half-joking, half-serious comments about it. (“Now don’t you [the woman’s partner] be booking time off work from that date onwards; it’ll just as likely come late in the due month as early [and] if the yard can’t be flexible about that, well you just tell them to call me [and] I’ll tell them.”)

In modern culture, it is not considered cool to be overdue – whether for a date, with a library book or when awaiting birth. And this can impact negatively on women. But maybe there are things that we can do about this, not just to help women to avoid fixed point expectation syndrome, but to help our whole society understand that seeking this level of certainty may not be a good idea.




Davies, R (2003). “I’m ready for you, baby, why won’t you come?” How long is a pregnancy and how long is too long? New Zealand College of Midwives Journal 28(1): 8-10.

Stickler, G B. (1994). Expected date of confinement (correspondence). The Journal of Family Practice 39(4): 325.

Van der Kooy, B (1994). Calculating expected date of delivery – its accuracy and relevance. Midwifery Matters 60: 4-7, 24.


Photo by NASA on Unsplash

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