In my house, time no longer matters.

My wife and I are both going to bed late at night, and waking up long after the sun rises, but our sleep in between is erratic and broken by periods of restlessness. It’s like we have become untethered to the cycles of the sun or any other outside conditions.

What had happened?

Something completely natural.

My wife was nine months pregnant.

The Perfect Storm

In late pregnancy, many changes come all at once for women, creating a perfect biological storm of sleeping troubles.  As if that wasn't enough, some women start to feel guilty about such changes because they affect their partner's sleep as much as your own.

My sleep during my wife's pregnancy - a number of extra awakenings.

However, I’m convinced these sleep changes are more than “random” byproducts of a changing body. I’m tempted to think there’s a design in this process that slowly acclimatizing parents to sleep in smaller chunks, with more vigilance.

But to what purpose?

Essentially, this month of crappy sleep prepares you for the polyphasic lifestyle that awaits after the baby is born.

The Real Deal About Polyphasic Sleep

Polyphasic simply means “many periods” of sleep, as opposed to our industrialized way of sleeping in a big lump, known as monophasic sleeping. 

We usually hear about polyphasic sleep in its most extreme form: the “Uberman sleep schedule,” which is a productivity life hack designed to cut sleep down to less than 5 hours a day so you can work more instead of “wasting” your time sleeping. In this form, polyphasic sleeping is something humans can do under stress and extreme situations.

However, polyphasic sleeping doesn’t have to be so extreme - or so restrictive.

Most of the world’s cultures actually sleeps biphasically, which simply means two sleep intervals: one at night, and another shorter nap during the mid-afternoon, when our circadian rhythms naturally drop. The siesta cultures of Spain and in Polynesia are two examples of this common pattern.

In addition, newborns, infants, and toddlers, to varying degrees, all sleep polyphasically - which means you're now getting up at all hours of the night because they're not sleeping in one big chunk like you.

Yet in both models, the goal is not to get less sleep, but simply to sleep when the need arises. I have a sneaking suspicion this is precisely the natural transition that occurs in late pregnancy.

However, there may be another reason for this call to sleep when you can.

Lessen Your Labor Time

Scientist Claudio Stampi, the godfather of restrictive polyphasic sleeping, was also a yachting enthusiast. Yachting races can last days, and necessitate the ship’s crew to go without sleep (or very little sleep). He published several studies making the case that sailors who cooperated so they could sleep in small segments routinely out-performed the sailors who attempted to not sleep at all.

A similar case has been made for shift workers who alternate sleep and work continuously. More recently, a 2009 study backed up this assertion, suggesting that “banking sleep” beforehand can improve performance during a subsequent stressful sleep-deprived event.

This seems to be the case even with childbirth. One study suggests that women who sleep less than 6 hours a night in late pregnancy have longer labors, and are 4.5 times more likely to give birth by cesarean.

So the more you sleep in late pregnancy, the better you will cope with the birth itself.

Why It's Good To Sleep When You Can

In this light, the news isn’t all bad for pregnant women. Yes, chances are, you are probably going to get less sleep, and lower quality sleep, precisely when you are hoping for more rest. This reality seems to spite the well-meaning (but annoying) comments from all those friends who say “Sleep in while you can!”

My wife's sleep, complete with 1:15hrs of Wake at the beginning, then another wake up just before 6am

They do have a point. Ultimately, the key to getting sleep during pregnancy is opportunistic: it’s about becoming flexible and adaptable to the body’s new, erratic demands (which may mirror those of your soon-to-be little one).

Personally, my wife and I have found it empowering to consider pregnant sleep as polyphasic and opportunistic, rather than just giving up on rest altogether. Rather than sitting in bed, completely frustrated, my wife has learned to get out of bed and do what must be done, which apparently includes stitching tiny pillows for the baby’s mobile at 3am. Other times, she quietly reads.

I respond by either getting out of bed and sleeping on the couch, or picking up my own booklight. Both of us also have started taking afternoon naps when possible. Once we gave ourselves permission, we came to really enjoy the break.

With luck and some planning, you’ll be able to get the rest that you need - without the additional stress!