Why Is Giving Birth So Hard? Revisiting the 'Obstetrical Dilemma'

Even more relevant passage from the article:

"Childbirth is difficult for many reasons, she writes—among them the 19th-century switch from birthing in the upright position, which allows the pelvic girdle to expand in response to contractions, to the supine position (still common among women in the West) which often requires the use of forceps."

There are correct times and places for all tools. But comparing two interventions that both bring risk is an odd way to approach the topic.

> And if forceps are used by inexpert doctors, the results can be disastrous.

"N of one", but I have a cousin who was mentally retarded/disabled during birth when forceps were used on his head.

Obviously I don't have proof of the cause (that would require a counterfactual birth), but he is disabled, has an abnormally oblong head, and this is the stated reason of the family (also not incontrovertible facts).

My understanding was that a large part of the reason was that unlike natural deliveries they can be scheduled and are thus far more convenient for the doctors.

I thought it was because of all the law suits brought about by the likes of former Sen. John Edwards.

One possible justification is that this genital configurations prevents forcible rape, as the wiki article points out. This allows females to have more control over the genetic traits of their offspring.

FWIW, it's now recognized that the parts of the human female anatomy that are sensitive to arousal (parts that are essentially analogous to the shaft of the penis and to the skin of the testicles in their sensitivity and in their ability to convey pleasure) surround the entire vaginal opening and portions of the vaginal wall.

No, they're not as sensitive as the clitoris (and no, I don't think we know precisely how sensitive the hyena clitoris may or may not be) but human women also give birth through tissue that is dense with nerve endings and more sensitive to both pleasure and pain than, say, that on the outer surface of your arm.

In general, vestigial traits hang around because there is little selection pressure against them, but new traits don't usually seem to show up & take over for no good reason.

IIRC, this also means that the first litter systematically dies off.

I vaguely recall a guide explaining this during a SafariLive stream[1]

1. https://wildearth.tv/safarilive/

Couldn't agree more. The book they cite (Happiest Baby on the Block) goes through the 5 S's and it's a life saver. His "4th Trimester" theory is just about the most sensible description of newborn behavior.

So true. The 5S's was like this magical switch that I could flip to chill out my screaming newborn. It was an incredible experience seeing how well it worked.

Why is sexual differentiation necessarily costly in every case? There are many sex differences that give an advantage for one gender that would have been an advantage, or no cost, for the other gender, but weren't as strongly required and so don't exist. Sexual differentiation may be less _likely_ for any given trait, but traits tend to pop up on random chromosomes, or the side effects of sex hormones be farther-reaching than necessary and evolution just "didn't bother to correct," and so I'd expect that some traits that don't necessarily need to be dimorphic (but are needed by one gender or the other) might become dimorphic just by chance.

Men have deeper voices than women. What would be the disadvantage for baritone women? You could argue that a deeper voice makes you less easily heard by prey... but then what's the advantage for women to have a higher pitched voice? Why didn't we all continue this trend to speak at the registry of blue whales? I suspect it's one of those things that "just sort of happened" and then it became a positive feedback loop spurred on by sexual attraction as a result of this initial differentiation, and now we're just at a pretty good state spurred on by a combination of random chance, survival advantage, and a little reproductive enforcement.

Increased sexual dimorphism (and a genetic/hormonal configuration that lowers the cost and increases the odds of sexual dimorphism happening for any given feature) is actually a positive thing for some animals depending on their social and reproductive strategies. When sexual dimorphism is high, you tend to see more random differences that pop up between the sexes but that may or may not provide any evolutionary advantage beyond "well, the other sex is just attracted to it now so let's keep this party going." When dimorphism is low, differences generally have to provide a stronger survival advantage.

Evolution isn't always straightforward or "carefully thought out." The hoops it jumps through aren't always costly and don't always have a rhyme or reason. It's often chaotic and and takes weird turns and it's not like humans are at a "final state" anyway. We're evolving.

I'm not _necessarily_ disagreeing with you (although it's probably ultimately easier to look at the physics, not biology, to prove or disprove your point) but I'm just saying that I think the situation is vastly more complicated than "sexual differences are costly." I don't think they're necessarily costly, simply less likely. A subtle, but important difference.

Mothers preserving energy and being able to carry more directly benefit the survival of offspring (since that's who they're carrying and where their surplus energy is going), whereas an improvement in those areas for fathers doesn't have as direct of an impact so it doesn't get selected for.

>without any benefit in return ?

Isn't the implied benefit that it might allow for an easier birth?

"in some particular tasks women are better"

I assume men's hips are still better for tasks traditionally associated with the male gender role - e.g. being hunters and warriors.

If we carried our children until they were sufficiently physically developed to stand, they'd kill the mothers in childbirth 19 times out of 20.

As our brains became more advanced, our crania became larger and more dangerous to birth at full term. But as our intelligence increased, so did our ability to care for infants that were essentially born premature.

So now even our full term babies are born so early that they need another 3 months (sometimes referred to as the "fourth trimester") just to be mature enough to sleep properly, among other things. But as intelligent humans, we're able to care for them and devise ways to carry them with us and protect and nurture them despite their extreme helplessness.

FWIW, the offspring of carnivorous mammals, though not born quite as "premature" as humans, are often as underdeveloped at birth as a 3-month-old baby. I mean, have you ever seen a newborn kitten or puppy? Eyes closed, barely able to crawl to its mother's teats?

The need for a prey animal - especially one that depends on speed for self-preservation - to be able to escape from within minutes of its birth is very different from the survival requirements for a carnivore or even a prey animal that gives birth in a hidden den (like many rodents).

Babies start crawling at about 6 months, and walking somewhere between 9 months and a year. I have a two year old, and she is far from helpless.

This is true, at least in my country there is a high amount of C-sections and studies show that most of them are done for the money.

I've read a couple articles that touch on this. The current theory has been summarized as there being an evolutionary arms race between genes that benefit the child at the mother's expense and genes that preserve the mother while being somewhat detrimental to the child's fitness (but as a result beneficial to her other offspring).

In this regard, longer gestation and a larger cranium are both better for the child. But our large crania are difficult to fit through the various choke points in the birth canal, and endanger the mother's life. The result is basically gestation as long as possible and crania as large as possible to permit natural childbirth to usually be non-fatal -- but that inflection point is one where even a non-fatal childbirth is difficult and painful.

(There are also elements of the theory that relate to frequency of fertility, and why human menstrual bleeding far exceeds that of other mammals.)

Because of the external gestation, my understanding is that survival rates for marsupial offspring are lower than for mammals. As for other mammals, giving birth is difficult for them too, though we don't have a way to measure how their pain compares to ours. However, no other mammal has gone down an evolutionary pathway where its fitness depends on brain size, so no other mammal has to contend with evolutionary pressures that so directly affect the ease of birth. (Plus, bipedal mammals with upright gaits are rare, so the evolutionary pressure affecting pelvic shape are different.)

To be fair to humans, we are born at a pretty early stage also. Human babies are all but helpless at 12 months after birth and pretty helpless for another 12 months after that (and then they are still rather helpless).

A kangaroo leaves the pouch in around 8 months.

Kangaroos are marsupials, which are non-eutherian. Humans (and, indeed, most mammals we're familiar with) are eutherians. The birthing process is quite different, and so makes for a poor comparison (for one, humans don't have a pouch). A better question would be to compare human pain to other, eutherian animals who do not experience much pain in delivery (see: any nature documentary).

Humans have large heads and walk upright. These are great for many things, but not giving birth.

Ineffective because natural selection doesn’t over optimize.

EEG suggests earlier born babies can have huge merits in intelligence evolution: https://www.scientificamerican.com/article/does-a-newborn-s-...

Well, you’re not alone in wondering that. In fact it was noted in the Bible as part of God’s curse when we became “enlightened” by eating fruit from the tree of knowledge. We’ve at least known it’s harder than it should be for a very long time.

We are very effective at breeding, especially with the help of science and technology. The inefficiency of birth, if true, hardly matters.

Do you mean kangaroos?

Firstly the people saying that birth is hard in this article are scienstists who study birth in humans. Human births are much longer, more complex, and more painful than most other mammals and this article goes into some arguments as to why that is.

I don't who these billions are that you're talking about, but historically giving birth has been a very deadly affair for women.

Spoken like someone who has never done it and never will, with only the confidence that comes from total ignorance.

Prior to modern medicine, childbirth killed perhaps a billion women. Even today, it's still a major cause of death for women of childbearing age. I sure wouldn't call it "just fine."

> Who said it is?

The article. Which quotes several expert anthropologists.

Your comment contributes nothing to the discussion and suggests that you haven't read the article.

Oh you guys should read "The Good Book of Human Nature: An Evolutionary Reading of the Bible" It explains a lot of the stories inside the Bible on a evolutionary way. https://www.amazon.com/Good-Book-Human-Nature-Evolutionary/d...

Talk about a shitty god.

Also Quran 46:15: "And We have enjoined upon man, to his parents, good treatment. His mother carried him with hardship and gave birth to him with hardship, and his gestation and weaning [period] is thirty months. [He grows] until, when he reaches maturity and reaches [the age of] forty years, he says, "My Lord, enable me to be grateful for Your favor which You have bestowed upon me and upon my parents and to work righteousness of which You will approve and make righteous for me my offspring. Indeed, I have repented to You, and indeed, I am of the Muslims.""