Ovulation to Implantation - Pregnancy Begins When?

April 12, 2023 7:53 AM

The surprising science of how pregnancy begins An illustrated, 7-day description with this context: "Defining exactly when a pregnancy begins is a hot topic in some state legislatures and U.S. courts at the moment. While federal law has long said pregnancy starts after a fertilized egg has implanted in the uterus, state law in Kentucky, for example, calls someone "pregnant" as soon as a sperm meets the egg. With so much riding on biology that's often misunderstood, let's break down what is known: Here's how the run-up to a pregnancy begins in that very first week of action, from the minute a single egg, the size of a grain of table salt, bursts forth from an ovary."
posted by reality_is_benign (33 comments total)

state law in Kentucky, for example, calls someone "pregnant" as soon as a sperm meets the egg

🎼 they're coming for your contraception 🎶
posted by saturday_morning at 8:06 AM on April 12, 2023 [36 favorites]

A really lovely thing about this article is that the words "woman" "man" "male" and "female" do not appear anywhere in it.
posted by seanmpuckett at 8:09 AM on April 12, 2023 [28 favorites]

What a fantastic article. I love the illustrations especially, with the little sound effects that help you understand what is going on. Thank you for sharing this!
posted by Zumbador at 8:22 AM on April 12, 2023 [1 favorite]

With so much riding on biology that's often misunderstood

Respectfully, "understanding the science" is not the slightest bit relevant to these discussions, not at all. Does anyone honestly believe that if Republican legislators "understood the science", they'd then stop trying to disenfranchise women or criminalize their agency over their own bodies? I'm glad these articles exist for the lay people but in terms of legislative relevance they aren't going to move any needle that anyone cares about.
posted by mhoye at 8:27 AM on April 12, 2023 [62 favorites]

Appreciated this too: "(Assisted reproductive technologies have greatly expanded how ovulation and fertilization can happen so that many more people can have babies. What we're describing here is what happens when that assistance isn't needed.)"
posted by martin q blank at 8:28 AM on April 12, 2023 [7 favorites]

🎼 they're coming for your contraception 🎶

Yes, and it is a disappointing choice that the article includes the line "In fact, most pregnancy loss happens before the fertilized egg implants," rather than finding language that does not pretty much explicitly accept a definition of "pregnancy" as happening prior to implantation. Though I kind of get it is in the spirit of the article to not choose a bright-shining-line-moment at all and call the whole thing pregnancy, and other than that, I really enjoyed this and learned some!

I've found the 1 in 3 statistic that immediately precedes the quoted sentence above to be a somewhat useful number when facing someone who believes that fertilization is indeed the bright-shining-line moment of pregnancy, because that belief is virtually always tied to a theology of ensoulment. Asking those folks why they think their God reaps 33% of souls before those souls even have a body at least makes them pause.
posted by solotoro at 8:29 AM on April 12, 2023 [13 favorites]

TIL that "how is babby formed" is a legit question.
posted by Halloween Jack at 8:30 AM on April 12, 2023 [12 favorites]

Where is the sound effect for the menstrual phase? I would like some "OW! FUCK! WHY?" please
posted by epj at 8:36 AM on April 12, 2023 [13 favorites]

> Respectfully, "understanding the science" is not the slightest bit relevant to these discussions, not at all.

the thing that really bothers me, the thing where they're failing on their own terms, isn't that they don't understand the science but instead that they don't understand the science or the theology. the bible tends to identify the start of life — not the start of souls, mind, but the start of life — as quickening rather than conception. and, like, identifying it as anything else requires modern medical technology!

the modern anti-abortion position, particularly in sola scriptura protestant sects, is a bunch of scientistic-but-not-scientific ideas swirled together with an illiterate interpretation of their own sacred texts.

like, puke.
posted by bombastic lowercase pronouncements at 8:38 AM on April 12, 2023 [26 favorites]

As a gay cis-man who's never tried to have children all this science is a bit fuzzy to me; it's great to read it explained so clearly and in such detail.

Is there an article somewhere that explains how various contraceptive methods prevent this process from happening? I was going to guess IUDs work on day 6 to prevent implantation, but it seems it's more like day 0 or 1. "Both copper IUDs and hormonal IUDs prevent pregnancy by changing the way sperm cells move so they can't get to an egg. If sperm can’t make it to an egg, pregnancy can’t happen"
posted by Nelson at 8:38 AM on April 12, 2023 [1 favorite]

A really lovely thing about this article is that the words "woman" "man" "male" and "female" do not appear anywhere in it.

Thanks for pointing that out. It is lovely, and part of what makes it work so well is that the wording is well-crafted and natural rather than clumsy; I probably wouldn't have even noticed this if you hadn't pointed it out. There are just a few references to the person whose body this is all happening within, e.g.:

If you were born with ovaries

the person who has had all these changes happening inside their body
posted by Dip Flash at 8:44 AM on April 12, 2023 [6 favorites]

Understanding the science probably won't lessen the drives behind the oppression, but it would at least help some. Plenty of people still believe that a pregnancy can be avoided by sheer willpower or the child's gender can be selected somehow or that every pregnancy is magically wonderful and safe and nothing bad can possibly happen to good people procreating in monogamous heterosexual marriages blessed by the faith institutions.
posted by Jacen at 8:55 AM on April 12, 2023 [5 favorites]

If you want to extend your knowledge, this Radiolab episode Everybody's Got One is all about the placenta. And wow! I tell you what, that was an eye opening journey!
posted by hippybear at 9:03 AM on April 12, 2023 [5 favorites]

> Understanding the science probably won't lessen the drives behind the oppression, but it would at least help some [...] every pregnancy is magically wonderful and safe and nothing bad can possibly happen to good people procreating in monogamous heterosexual marriages blessed by the faith institutions.

maybe i'm too jaded, but i'm convinced that once someone's spent enough time steeping in the just world fallacy, no amount of rationality or calm explanation can pull them out of it. you might get them to admit that sometimes maybe possibly there's someone out there who's had a bad thing happen to them, like a bad bad thing and not something with a silver lining, and who didn't deserve it. but the second the conversation's over they revert back to thinking that bad things, really bad things, can't happen to good people.

the only thing, i think, that snaps them out of it is having a bad thing happen to them personally. but even in that case they often acknowledge that that particular bad thing can happen to good people and that it is therefore a problem, but without acknowledging the possibility that there's other bad things that can happen to good people too.
posted by bombastic lowercase pronouncements at 9:10 AM on April 12, 2023 [13 favorites]

So it didn't mention the embryo hatching. When I did IVF they did something to the embryo's to encourage them to "hatch" which they said was necessary for implantation. I read the article hoping for an explanation of hatching. I notice in this picture the contents seem to spill out of the membrane. Maybe that's it? But then the membrane is back on the outside, so I don't know.
posted by If only I had a penguin... at 9:51 AM on April 12, 2023 [2 favorites]

So I like to go with malicious compliance as a protest sometimes. And it strikes me that if, in a place where they use fertilization as the metric, if there are any services offered to those suffering from a miscarriage - a public OR a private one - women could start applying for them EVERY month, saying that "hey, you never know, I could have been."

Granted, this would make things heinous for women who really need those services so maybe not such a good idea. But places like this probably don't offer assistance anyway. But wouldn't it be awesome?
posted by EmpressCallipygos at 10:06 AM on April 12, 2023 [2 favorites]

So it didn't mention the embryo hatching.

Probably referring to zona pellucida breaking open as the blastocyst enters the uterus. Recall that this layer hardens to prevent double fertilization, and stays wrapped around the zygote to keep it from getting stuck in the fallopian tubes.

It’s been a long time since I taught developmental bio, but I’m confident that is what your IVF team meant by “hatching”
posted by caution live frogs at 10:13 AM on April 12, 2023 [6 favorites]

Fun fact I learned when I had a job that dealt with pregnancy statistics:

"x weeks pregnant" counts from the end of the last menstrual period, typically 14 days before ovulation. Since you can't become pregnant before ovulation, it's (usually) impossible to be one week pregnant - at the moment of conception, you are immediately two weeks pregnant.

Upon learning that, my comment was that while anti-abortion people will tell you life begins at conception, we're doing them one better and counting it from two weeks before conception.
posted by Hatashran at 11:16 AM on April 12, 2023 [14 favorites]

All persons with ovaries are pre-pregnant until post-menopause or death. This is already affecting gynecological healthcare in various ways. Doctors are declining to care for patients for certain conditions before a pregnancy test. This isn’t so new, I had to take a pee test before my colonoscopy recently, for example. But pee tests don’t pick up on pregnancy before the first missed period. And can be unreliable in the early part of first trimester (which includes BEFORE you were pregnant). Given the criminalization of medical providers in certain areas, they will want to make sure you aren’t very early pregnant. A blood test may be more accurate but adds to the cost of your visit and may add to the time to get analysis done especially if they are backed up or don’t have the ability to test on-site. Time can be deadly. Adding hoops to healthcare can be deadly. But who cares? It’s just women and girls. We’ll force them to breed more.
posted by amanda at 12:02 PM on April 12, 2023 [10 favorites]

The thing I always want to ask prolifers - ok peeps - if you menstruate and have sex - do you have a funeral for each individual pad/tampon/dump of your cup? Or do you save it all up and have a funeral at the end? Because if life starts at conception, and sometimes you lose the life before you're aware of it - to dump those items in the trash or wherever is abuse of a corpse? Right?
posted by Gyre,Gimble,Wabe, Esq. at 12:30 PM on April 12, 2023 [6 favorites]

The desire to control/punish women feeds the desire to make something that is complex (conception, gestation, fetal development) simple. If all fertilized eggs are beings with rights equal to/greater than a woman's, you don't have to think, only control the fate of that fertilized egg.

It also has the side benefit of erasing the work of gestation and the reality that sperm provide only half a blueprint while the woman's body does the actual, mind-boggling work of physically creating another human being (with all the risks that entails), a truth that makes sexist men feel very unimportant and uncomfortable.

The desire to control/punish LGBTQ people feeds the desire to make something that is complex (gender, sex, desire, identity) simple. If men and women are a simple binary that should not ever be challenged, then again, no thinking is required, just punishing deviance.

Like all conservative delusions, it would be comedic if it didn't kill people.

I don't believe it's impossible to push people out of those simplistic ways of thinking, especially if they have, for example, had a miscarriage or cared about someone LGBTQ. But those ruts run deep and you have to push pretty hard.

For me, growing out of the antichoice idea was partly due to realizing how complicated gestation is and how many ways it can go wrong, or simply self-terminate, as well as how pregnancy is used as a method of control by abusers who do things like throw away contraception. I'm not a Christian anymore but if God was truly ok with tossing so many fertilized eggs before they got further, then clearly he didn't think of them as precious babies yet. And I couldn't bring myself to believe in a God who would keep a woman with her abuser as well as now endangering any child she has.

But I had to be pushed to ask those questions. I had a lot of angry arguments and a lot of people cut me off for being an asshole/tell me to educate myself. Women who I otherwise admired, especially.
posted by emjaybee at 12:59 PM on April 12, 2023 [17 favorites]

This is all fine, but please remember that it is important (but not yet mandatory) to respect people's sincerely held beliefs and under Jewish law life (in the sense of being considered a fully distinct entity) begins when the baby draws its first breath outside the body of the mother and that ending a pregnancy is not only permitted but required in cases where her life is in danger. (And we have many, many stories of doctors being aware such care is needed but hesitant to act due to the possible legal repercussions, often leading to disastrous complications or death) so the reality is that the vast majority of these proposed or enacted restrictions on access to abortion care are (in addition to, you know, killing people and making society worse as a whole) infringing on my religious freedoms.

Remember friends, would-be Christian fascists hate us all.

And while we're on the subject, why is the "pro-life" movement opposed to healthcare rather than war, death penalties, the continuing militarisation of police, an outrageously punitive rather than restorative criminal justice system, etc.
posted by seraphine at 12:59 PM on April 12, 2023 [22 favorites]

And while we're on the subject, why is the "pro-life" movement opposed to healthcare rather than war, death penalties, the continuing militarisation of police, an outrageously punitive rather than restorative criminal justice system, etc

At the risk of sounding like I'm a fan of the Catholic Church, the Catholic church actively opposes those things. Also, MAID and often withdrawal of medical treatment. There's a lot of hypocrisy in the church for sure, but on the "we think nobody should ever do anything to prevent someone from continuing to be alive" point they are pretty consistent.
posted by If only I had a penguin... at 4:14 PM on April 12, 2023 [1 favorite]

Respectfully, "understanding the science" is not the slightest bit relevant to these discussions, not at all.

Yes. They're actively writing laws that pretend to be science (i.e., heartbeat laws) and when MDs testify that they're not accurate, said MDs are simply ignored.
posted by CheeseDigestsAll at 8:21 PM on April 12, 2023 [1 favorite]

I'm not a Christian anymore but if God was truly ok with tossing so many fertilized eggs before they got further, then clearly he didn't think of them as precious babies yet.

my understanding is that a lot of fertilized eggs which self-terminate early in the process do so because a chromosomal abnormality has rendered them non-viable, therefore they don't send the proper chemical signal to prepare the uterus for implantation, therefore they don't implant

so yeah if God wants every fertilized egg eventually born as a baby, why is he not doing a better job with chromosomal viability on the gamete level, is what I wanna know

to be less flip I feel like some (not most) pro-lifers are actually empathetic, well-meaning people with unrealistic/simplistic ideas about How Shit Works, like "all pregnancies go well" & "you can just give a kid up for adoption, that's easy" & "a fetus is functionally a baby & it's wrong to kill a baby" & "it's totally normal & beneficial to punish people for the wrong kind of sex" & "pregnancy is a magical time which doesn't require your body to set up defenses so you're not sucked dry by the arguable parasite inside of you" & "social services exist to take care of everyone who has an unplanned baby so it's fine" etc. etc.

& shit, if it's possible to get any of these people on board with a more nuanced worldview, at least it depletes the number acting as footsoldiers for the people frothing at the mouth to do a Handmaid's Tale

idk how receptive they might be, though, I alienated all of 'em years ago & we don't talk anymore
posted by taquito sunrise at 9:10 PM on April 12, 2023 [3 favorites]

Fun fact I learned when I had a job that dealt with pregnancy statistics:

"x weeks pregnant" counts from the end of the last menstrual period, typically 14 days before ovulation.

Actually, "x weeks pregnant" counts from the first day of the last menstrual period , not the end.
posted by M. at 10:56 PM on April 12, 2023 [6 favorites]

I often feel that pregnancy is so ridiculously complicated it's surprising that humans manage to sustain a population increase. This kind of excellent, clear and focussed writeup of how it works on the "happy path" right at the beginning does nothing to dispel that feeling for me. So much of this can go wrong, there are so many mechanisms that have to work just right to get an egg and a sperm to meet, to get only one sperm inside the egg, to get the genes to combine in a viable way, to implant successfully, then the ridiculous things the developing embryo does to form the alimentary canal and the start of the organs and the like...

Also I was wincing in the bit about sperm getting to the uterine tubes thinking about ectopic pregnancies. No wonder that's so painful and dangerous.
posted by mathw at 1:31 AM on April 13, 2023

“Ovulation to implantation - homicide begins when?”

Not only have maternal mortality rates been increasing but the leading cause-LEADING CAUSE-of pregnancy and post-partum death is homicide. Who is killing them? And how many people face mild to extreme abuse throughout their pregnancy by these people who would kill them for daring to gestate? From loving husbands and boyfriends to rapists and abusers to brothers, fathers and who knows who else…. For some people, that ejaculation starts a running clock on their own life. LEADING CAUSE.
posted by amanda at 7:28 AM on April 13, 2023 [3 favorites]

One notable shortcoming in American political discourse and functionality has to do with this:

If I, as a progressive, were a legislator or political executive who wanted to impose strong regulations on, say, the gun industry and I demonstrated -- repeatedly -- that I did not know the difference between a clip and a magazine or between the different types of cyclic rates, the right (and the center, including the American media, and even some parts of the left) would howl with outrage, and I would face strong opposition, if not outright negation, of every measure I tried to impose.

But if I, as a cishet male, were a legislator or political executive who wanted to legislate total control of the reproductive health of people with uteruses and I demonstrated -- repeatedly -- that I knew sweet fuck all about biology? Shrugs from the right and most of the center, including the American media...especially if I invoke my personal religious beliefs as part of my decision-making process.

These aren't hypotheticals, I've seen both scenarios play out time and again. It's...ridiculous. It's stupid, and it leads to all kinds of needless suffering, and it's seldom commented on by the talking heads online and on television.
posted by lord_wolf at 9:33 AM on April 13, 2023 [7 favorites]

...especially if I invoke my personal religious beliefs as part of my decision-making process

I mean, some people think the freedom to worship Jesus and the right to bear arms are one and the same. Extremely effective to link worship of your own internal concept of a Deity to anything and everything that keeps certain people in power and wealthy and certain other people subjugated. It's a winning combination worldwide for as long as we've been keeping records.
posted by amanda at 10:56 AM on April 13, 2023 [1 favorite]

> they're coming for your contraception

I would LOVE to see the Dems draft a law codifying the right to contraception and put it up for a vote. Would it get past the Senate filibuster? I don’t know, but I’d like to get Republican votes on the record.
posted by maleficent at 11:38 AM on April 13, 2023

maybe i'm too jaded, but i'm convinced that once someone's spent enough time steeping in the just world fallacy, no amount of rationality or calm explanation can pull them out of it.

I've been spending time on r/exchristian recently, and this is the kind of resource that's useful for people who've been immersed in one worldview their whole lives but are starting to realize that there are better worldviews available.
posted by clawsoon at 4:19 PM on April 13, 2023

This is awesome. Wonderful use of drawings and animation. Is there similar overview of what happens next? Does the egg pop out of endometrium at some point or does the endometrium expand to become the placenta?
posted by hermanubis at 4:24 PM on April 13, 2023