An essay on the biology of pregnancy

August 8, 2014 6:56 AM

"The mammal mother works hard to stop her children from taking more than she is willing to give. The children fight back with manipulation, blackmail and violence. Their ferocity is nowhere more evident than in the womb [...] Pregnancy is a lot more like war than we might care to admit."
posted by daniel_charms (28 comments total)

EMBRYOS GONE WILD! No tissue is safe!
posted by ThePinkSuperhero at 6:59 AM on August 8, 2014 [1 favorite]

Dr. Suzanne Sadedin, Previously
posted by the man of twists and turns at 7:13 AM on August 8, 2014

There’s something they rarely tell you about motherhood: it turns women into genetic chimeras.

I wonder if that has any effect on autoimmune disorders.

I had come in to make a snarky remark about the war on women and how this supports the right to choose, but if a 2nd or 3rd trimester abortion is the same, geneticalfuturally the same as having given birth I'm not sure if that gives more or less ammunition to the anti-abortion movement.
posted by Buttons Bellbottom at 8:00 AM on August 8, 2014 [1 favorite]

I could never get behind the "trust birth" approach to pregnancy and childbirth. Articles like this confirm my bias!
posted by Wavelet at 8:15 AM on August 8, 2014 [2 favorites]

Understanding the facts presented here makes pro-life arguments seem ridiculous. There's nothing "special" about an embryo. They're all little selfish parasites that die at a 50% clip when they don't perfectly match up with the conditions of their gestation. That women occasionally CONSCIOUSLY get rid of them shouldn't matter any more than the millions of times women unconsciously do it every year.
posted by norm at 9:08 AM on August 8, 2014 [9 favorites]

I shouldn't have read that while pregnant. Now I'm warily eyeing my abdomen, imagining a tiny, cackling, mustache-twirling embryo.

"yes, yes! soon all the nutrients shall be MINE! More cortisol! Increase the blood sugar! AHAHAHAHA"
posted by castlebravo at 9:16 AM on August 8, 2014 [25 favorites]

There’s something they rarely tell you about motherhood: it turns women into genetic chimeras.

For reasons lost to science-fiction, I immediately got this image in my head.

Given the invasive nature of pregnancy, it’s perhaps not surprising that the primate womb has evolved to be wary of committing to it.

As a non-breeder I started to get lost here, and for reasons I started to wonder if it was a pro-C-section piece, but it all kinda makes sense to me.

That women occasionally CONSCIOUSLY get rid of them shouldn't matter any more than the millions of times women unconsciously do it every year.

I just don't think you share the same mind-space as the people who might not agree with you.
Monty Python had a song that might help.

I think the current argument is that a miscarriage is natural and must never be spoken about again - EVER - because natural, and you just ignore that blob of potential stuff you might have seen and never speak of it again, but abortion is different because you chose it, you miscreant, you chooser of choices!
posted by Mezentian at 9:19 AM on August 8, 2014 [4 favorites]

I shouldn't have read that while pregnant. Now I'm warily eyeing my abdomen, imagining a tiny, cackling, mustache-twirling embryo.

Best 3D ultrasound .gif EVER.
Seriously.

also congrats! We're all counting on you!
posted by Mezentian at 9:20 AM on August 8, 2014 [2 favorites]

I hadn't realized how unusual the homo sapiens placenta was until I read the Quora piece in the previously. I was aware of the conflict -- they don't call it a parasite for nothing -- but didn't realize that the extreme lethality of human pregnancy was in large part because the fetus sets the woman up for hemorrhage by paralyzing the blood vessels to prevent the host's control of them.

But yes, confirms my opinion that an unwanted pregnancy is a medical condition that should solely be under the control of the woman.
posted by tavella at 9:29 AM on August 8, 2014 [11 favorites]

The correlation of high oxygen intake during early gestation with brain size makes me wonder if we could super-charge intelligence with bottled oxygen during pregnancy.

Or just create big-headed kids
posted by TheProfessor at 9:32 AM on August 8, 2014

makes me wonder if we could super-charge intelligence with bottled oxygen during pregnancy.

I think they call that Mad Science.

(I'll get Thomas Dolby on the phone!)
posted by Mezentian at 9:39 AM on August 8, 2014

Super interesting read. I'll add this to my list of reasons to never have kids.
posted by Librarypt at 10:09 AM on August 8, 2014

Comments on the article are actually pretty good and Dr. Sadedin is actively replying to them.
posted by annekate at 10:17 AM on August 8, 2014 [1 favorite]

Holy shit, the comments on the article are actually metafilter-level intelligent. Which is to say, not stupid. I am not accustomed to this. What's up, internet?
posted by selfmedicating at 11:17 AM on August 8, 2014

I am not accustomed to this. What's up, internet?

Reality inversion?
posted by Mezentian at 11:32 AM on August 8, 2014

Several comments seem disgruntled that the author uses such violent metaphors (war, bloodbath). I can't help but notice it's one or two men. I've been pregnant twice, have 2 kids, love 'em like crazy -- but there is a reason I referred to each of them as "the parasite" while they were in utero.

When you're getting lightheaded walking up a small incline, it becomes really obvious that you and the parasite are locked in a battle for oxygen, and the parasite is winning. I knew that fetal hemoglobin is different from normal hemoglobin - it's better at grabbing and holding oxygen, so the parasite literally is winning. This is fascinating, but from my own experience, not surprising.
posted by selfmedicating at 12:05 PM on August 8, 2014 [11 favorites]

I found the article sensationalist and the metaphor of pregnancy as "war" a little strained - it's much better to speak of a "cooperation" since the typical outcome is beneficial for both parties, and what can be construed as a "tug of war" can with equal validity be seen as a carefully coordinated dance. The author herself expresses this in the comments:
"[Pregnancy is] a war in the loose sense that there is violent conflict at the border between mother and child. [...] Of course, in other ways it's not a war at all. In general it's not in the interests of mother or child for either to die or suffer, and there are many aspects of their relationship that aren't ridden by conflicts. Like most metaphors, it has limited scope."
posted by tecg at 12:25 PM on August 8, 2014

Understanding the facts presented here makes pro-life arguments seem ridiculous. There's nothing "special" about an embryo. They're all little selfish parasites that die at a 50% clip when they don't perfectly match up with the conditions of their gestation. That women occasionally CONSCIOUSLY get rid of them shouldn't matter any more than the millions of times women unconsciously do it every year.

And, because it's likely the development of our big brains that resulted in this resource tug-of-war, is it perfectly sensible that we use that big brain as part of the selection criteria for carrying a pregnancy (or not as the case may be).
posted by [insert clever name here] at 1:34 PM on August 8, 2014 [5 favorites]

LOL (but not really) at selfmedicating's comment immediately followed by tecg's.
posted by valrus at 2:07 PM on August 8, 2014 [6 favorites]

There's nothing "special" about an embryo. They're all little selfish parasites that die at a 50% clip when they don't perfectly match up with the conditions of their gestation.

As are, in a state of nature, babies.
posted by ThatFuzzyBastard at 2:55 PM on August 8, 2014 [1 favorite]

There’s something they rarely tell you about motherhood: it turns women into genetic chimeras.

I wonder if that has any effect on autoimmune disorders.

Thank you for asking that.

I have a genetic disorder. I have speculated a fair amount about the impact pregnancy had on me. One impact I know for sure: My first very difficult pregnancy, where I threw up for 8 months, forced me to make dietary changes, many of which became permanent habits. I am sure this went a long way towards reducing how much I suffered over the years (I was not diagnosed until late in life). But I have been wondering a lot about the nature and extent of what having children did re my medical condition and that's a very helpful question for me to hear.
posted by Michele in California at 3:00 PM on August 8, 2014

I wonder if that has any effect on autoimmune disorders.

Here's one data point: Pregnancy is known to reduce the number of relapses in multiple sclerosis patients (presumably because pregnancy suppresses the immune system).
posted by tecg at 4:56 PM on August 8, 2014 [2 favorites]

I have no problem with the violent metaphors. People forget that evolution neither cares about individuals nor strives for anything like "perfection." The hormonal war described in the OP is just that, a war, and it's one that nearly killed both me and my own mother -- although nobody realized that was what had happened in 1964, when we both spent several weeks in the hospital before we were able to go home.

Our ancestors noted the extra difficulty that humans have with pregnancy and birth compared with other animals and drew what looks like it might be a correct correspondence between that difficulty and the intelligence that separates us from those animals. And of course the founders of what became three of the world's most popular modern religions did a righteous job of blaming the victim which poisons our attitudes to this day.

Intelligence has obviously worked well enough for primates, including those we continue to consider animals, that evolution has pushed in that direction despite the increasing difficulties of gestation. As with the extreme example of Diaea ergandros, eaten by its own offspring, evolution doesn't care what happens to you as long as enough of the people with your gene manage to pass it on.
posted by localroger at 5:01 PM on August 8, 2014 [3 favorites]

"I wonder if that has any effect on autoimmune disorders."

The significance of fetomaternal microchimerism remains unclear. It could be that fetomaternal microchimerism is an epiphenomenon of pregnancy. Alternatively, it could be a mechanism by which the fetus ensures maternal fitness in order to enhance its own chances of survival. In either case, the occurrence of pregnancy-acquired microchimerism in women may have implications for graft survival and autoimmunity.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2633676/
I am very much not a scientist but this subject has been making the rounds lately.
posted by vapidave at 7:09 PM on August 8, 2014 [3 favorites]

Pregnancy seems to cause remission of some auto-immune diseases, but not others. Here's an interesting explanation of remission in rheumatoid arthritis during pregnancy. Unfortunately, this is not true for all auto-immune diseases: for instance, ankylosing spondylitis and lupus. (As a person with AS, this is among the reasons that I fight very hard for my right to not be pregnant.)
posted by hydropsyche at 4:58 AM on August 9, 2014 [5 favorites]

There's an awesome Radiolab short, Fetal Consequences, on just this question.
posted by deludingmyself at 1:47 PM on August 9, 2014

"Pregnancy seems to cause remission of some auto-immune diseases, but not others."

It, from what I've read, seems that the fetus will assist the maternal parent while in the womb though there may be post-partum consequences for the mother. It's all theoretical for this old man of course [except I may have inflicted this on my mom].
posted by vapidave at 7:22 AM on August 16, 2014

That is a bizarre way to describe it, and completely contrary to the science in the FPP or my comment. What's happening is that the mother's immune system is being suppressed so that it doesn't attack the fetus. No "assisting" or anything nice is happening--it's very adversarial.
posted by hydropsyche at 10:21 AM on August 16, 2014