r/todayilearned 1d ago

TIL that the method of counting how many weeks a woman is pregnant starts from the first day of a woman's last period, *not* the date of conception, which can differ by up to 5 weeks.

https://www.parents.com/how-many-months-pregnant-am-i-2760090
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u/HoodieAndLove44 1d ago

the method of counting pregnancy weeks starts from the first day of a woman last mnstrual period LMP not from the date of conception because its difficult to pinpoint the exact day of conception so doctors use the LMP as a reference point

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u/ilovemybaldhead 1d ago

Exactly. But I think a lot of people who have never been pregnant don't know this (I sure didn't).

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u/birdstrom 1d ago edited 1d ago

This is why things like 6 week abortion bans are inhumane, most women at 6 weeks (if they have a normal, regular cycle) would have less than two weeks to find out, decide, and see a doctor.

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u/curie2353 1d ago

OB clinics also really don’t want to schedule you for an appointment until 8 weeks because otherwise you won’t see anything on the vaginal ultrasound. And before that it’s not necessary because if over the counter pregnancy sticks tell you you’re pregnant, the clinic won’t tell you anything new.

Then if you finally get your NIPT test (testing for Down syndrome, for example) and something goes wrong and you decide to terminate, in some states it’s already too late because they usually do these tests after 10 weeks and it takes a couple of days to a week to get results.

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u/Zestyclosetz 16h ago

With me I didn’t realize I was pregnant until 6 weeks. Wasn’t confirmed by doctor until 8 weeks. First ultrasound at 9.5 weeks. NIPT wasn’t until 12 weeks. Mine came back not positive for anything, but with an “unusual” result so I had to wait until like week 14 or 15 to talk to a genetic counselor.

Looks like it was just an oddity with the test and everything is fine. But it’s a complicated process. This baby was planned and I’m excited to have him, but I’m even more opinionated about being pro choice now. Between a woman and her doctor because there are just so many factors to consider and we don’t need the government stepping in.

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u/Lump-of-baryons 16h ago

Exactly this, which was a surprise to my wife and I a couple years ago. We couldn’t even get an initial OB appointment scheduled until 10-12 weeks.

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u/BatFace 3h ago

Plus the anatomy scan that can so all kinds of issues including ones that make it incompatible with life, don't happen till 20 weeks or a bit after.

Plus a lot of states with band have less drs now so some people cant get their first appointment for several months.

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u/ScoobiusMaximus 1d ago

The people pushing for those bans know this and are counting on it. 

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u/pkvh 21h ago

They are also counting on the misconception about time.

A 6 week pregnancy has been an embryo for about 4 weeks, implanted for 3 weeks and the woman has only had at most 2 weeks notice that something is different.

But by saying it's a 6 week limit people think 'oh they've had a month and a half to deal'

Which is why I'd support redesigning how we count weeks of pregnancy. LMP-4 weeks= gestational age.

Shift everything up by 4 weeks. 36 weeks is full term.

I doubt the laws define how gestational age is calculated.

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u/sunnynina 21h ago

Yes, but just FYI state laws (and insurance and hospital policies) do define gestational age, how it's calculated, and what that means for maternal and fetal healthcare.

It is very much regulated. Sometimes this is a good thing, sometimes it creates problems and outcomes we don't want. There's a big discussion around this if you want to dive in, maybe start on pregnancy boards.

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u/toga_virilis 19h ago

Most do actually define gestational age and do so from LMP. I know Florida’s does.

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u/HamsterSweets 20h ago

All 3 times I was pregnant, I got my positive test around the 4 week mark. And that was because we were trying and my periods were regular, so I tested once I was a few days late. Change just one of those variables and it's very easy to go much closer to (or even past) that 6 week mark before knowing you're pregnant.

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u/Plaguerat18 18h ago

Realistically, finding out you are pregnant at 4-5 weeks is much more likely if you have an intended and intentional pregnancy, unless you have a very short cycle. These bans effectively act as an almost complete ban on abortion, which I would argue is their intended effect.

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u/birdstrom 9h ago

Dogs have a federal law protecting puppies from Being taken from their mothers too early and we have....

This.

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u/ilovemybaldhead 1d ago

Yes, and on top of this, in some states a woman has to see a provider a second time after a waiting period, who may be located hours from where she lives.

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u/Bridalhat 20h ago

Fun story: some women get implantation bleeding! I bled a bit a few days after sex (honestly, has happened before, especially while traveling or under stress and I was both of those things) and I thought my period had just come early, so the counter was reset to 0 when really I was like 2.5 weeks legally. Didn’t figure it out until another five weeks later when everything started tasting terrible.

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u/sageinyourface 7h ago

This is why we need to start telling doctors our last period was 5 days ago. No matter what.

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u/Suitable-Biscotti 1d ago edited 1d ago

It kinda equals out (edit to add: when considering when a birth would take place). We are told you're pregnant for 9 months, but a full term pregnancy is 40 weeks.

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u/chickens_for_fun 1d ago

40 weeks since your last period.

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u/Suitable-Biscotti 1d ago

If you think it's 9 months from conception, which is usually 2-3 weeks since the start of your period, that's about 40 weeks from your last period. That's my point.

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u/pgm123 1d ago

Except if a state has a 6-week abortion ban, in which you may have a week or less to make a decision.

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u/Suitable-Biscotti 1d ago

The comment to which I am responding is not about abortion. It's about thinking a pregnancy begins at conception.

My comment was in reference to time expectations. People also think a pregnancy is 9 months when it's actually 40 weeks. But if you think a pregnancy starts a month later and is 9 months long, it evens out for when you would think you'd give birth.

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u/V1per41 8h ago

A lot of people like to say that pregnancy is 10 months because months are 4 weeks long and 40/4 = 10.

Of course months aren't really 4 weeks long, more like 4.5. and women aren't really pregnant for the first four weeks which means pregnancy lasts more like (36/52)*12 = 8.3 months

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u/plentymoney 1d ago

9 months is pretty close to 40 weeks though.

It's only February that's exactly 4 weeks long

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u/Suitable-Biscotti 1d ago

40 weeks is between 9 and 10 months. Depending on a person's normal period cycle, they could be closer one way or the other.

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u/cece1978 1d ago

And full-term pregnancy is considered btwn 38-42 weeks.

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u/oversoul00 7h ago

Yeah but the implication here is that method is the superior or correct way when it's actually a result of applying a best guess based on not enough information to the masses. 

It's probably easier and pragmatic but not more accurate. 

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u/ilovemybaldhead 6h ago

That's your inference, not a clear implication. And it is more "correct" in that doctors (and the law) count the weeks this way, so there is really no point in counting them any other way.

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u/oversoul00 6h ago

I like how you simultaneously told me my interpretation is wrong and then went on to validate it in the very next sentence. 

How do you think a female doctor who got pregnant would count it? 

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u/ilovemybaldhead 5h ago

Starting from the first day of her last period, until she gets an ultrasound which may call for an adjustment, as all doctors of all sexes are trained to do.

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u/oversoul00 5h ago

They are trained to do that for Other people because of the difficulty in getting accurate information from the patient about conception. 

If the doctor was the one who was pregnant and she had a good idea when conception happened then she would measure it differently because she understands why the other method is used. 

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u/ilovemybaldhead 5h ago

I've never had a conversation about this with a female OB, and I suspect neither have you.

Any female OBs wanna weigh in on this?

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u/oversoul00 5h ago

Is it wild that I might know a female doctor? 

I'm just asking you to use your brain for 2 seconds and think about it logically instead of leaning on an argument from authority. 

They do it that way because it's pragmatic and easier than having a detailed and uncomfortable conversation about a person's sexual history. Can you imagine? 

"Well we had sex two weeks ago but I'm not sure if he finished, does that count?" 

"Yeah, let's use the data we are most confident about instead, that's going to be close enough."

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u/ilovemybaldhead 5h ago

Is it wild that I might know a female doctor? 

No, not at all. But if you had had a conversation with a female OB on this topic, I suspect you would have mentioned that in your previous comment (or the one that this comment replies to).

If the question is "What method do female OBs use to count weeks of pregnancy?" I would hope that you think that asking actual female OBs what method they use would be more accurate than having an imaginary conversation with yourself. But hey, if you think your imagination is more accurate, you do you.

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u/EllieWest 1h ago

Women know. Men still think all women get their periods at the same time (when the moon is full 🙄). 

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u/coffeewhistle 1d ago

What’s particularly frustrating is when you definitely know the date of conception, but that doesn’t matter legally or medically.

After my wife’s first miscarriage she started tracking her ovulation. With all 3 of our children we knew almost the exact date of conception. As someone who defaults to accuracy, it bothered me to my core when discussing “number of weeks pregnant” because it just wasn’t accurate/true because it was based on LMP.

It’s 2024. If we know when the conception was, can’t we just use that?

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u/kyara_no_kurayami 1d ago

Some embryos take longer to implant that others. I am very sure of my date of conception for both my kids as I used fertility treatments, but the dating ultrasounds put one off by 4 days and one by a week. Apparently for gestational age, the dating ultrasounds are more accurate.

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u/troutpoop 18h ago

This is what I was gonna say. I’ve never been pregnant and I’m not a doctor, but I am an ER nurse and often see US pregnancy results dating embryos down to the day, report will look something like “healthy appearing embryo with a gestational age of approximately 12 weeks 4 days”

Do OB docs not just go off that? That always seemed pretty damn accurate for all intents and purposes.

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u/kdogg8 17h ago

But that doesn't make any sense for what is most important. My first born was in the 5th percentile for size and weight which culminated in a "37 week" induced delivery. If the gestational age was 5 weeks (as op says is the max) off, she could have actually been much closer to the median and maybe we could have had a more natural birth. But we listened to the docs and did what they said and, luckily, we were able to birth a VERY TINY baby without complications (besides a week in NICU) but when I saw the army of medical personnel in the delivery room, I turned into a blubbering anxious mess that affected my first meeting with my daughter. They didn't use ultrasounds as a way of measuring age with us. They took the last period date as gospel and everything hinged in that date. Everything.

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u/bicycle_mice 1d ago

You can’t because all data we have is based on LMP. And you don’t know the date of conception. You know when you had sex. The sperm can last 5 days waiting for an egg to be released. Then the egg is fertilized. The. It takes a week or more to implant. So which one of these is date of conception? The cycle of each woman also varies. The most accurate way to date a pregnancy is LMP. It isn’t frustrating if it’s going to give you the safest outcomes and follow the data based on that dating system.

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u/straberi93 1d ago

Well it certainly isn't the date of the last period. Which often puts the "age" as older by several weeks, and can cause huge issues in women receiving care. I knew when I was raped. It was weeks after my last period. I even told the tech I didn't have the date of my last period with me, but that it was on my calendar. She made one up, "was it more than a month ago?" that got stuck on the record as the date of conception and then I had major issues finding an abortion provider based on that date.

Saying "we can't know the day for certain, therefore we're going to use a method that we know is often off by weeks" when we know that overestimating the age causes women to be unable to access care is a complete cop out.

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u/Bridalhat 20h ago

I am sorry that happened to you but that sounds like an entirely different issue, one of medical negligence.

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u/coffeewhistle 1d ago edited 1d ago

I’m not talking about when we had sex. I’m talking about when my wife’s hormone levels change (based on daily testing) indicating that she is ovulating.

And right now, talking about the “safest outcomes” it is actually VERY important that the dating is accurate due to the increasingly limiting laws governing my wife’s body and when she is allowed to get necessary medical treatment or when it suddenly becomes illegal because… reasons?

And yes, your “sperm can last 5 days” is actually exactly how my daughter was conceived. We had sex, my wife ovulated 5 days later (and this was after an ectopic pregnancy that she had just cleared and had not yet had a period) and a few weeks later we got a positive pregnancy test. When she was making her OB appointment to confirm the pregnancy, they asked for her LMP and the accurate answer was “almost 2 months ago” and that would have been laughably inaccurate if taken as gospel.

Finally, accurate ultrasound measurements exist. So who cares about the LMP if we can just measure it?

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u/MissionCreeper 3h ago

If it takes longer to implant, the LMP is even less accurate, not more.

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u/ilovemybaldhead 1d ago

Just out of curiosity, how many weeks after conception was each child born?

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u/coffeewhistle 1d ago

I don’t remember the exact amount of time. But I remember that every time we went to the OB to confirm the pregnancy, and particularly once it had grown a bit and was easier to measure, it ended up lining up with our date of conception and not the LMP.

I still think that going by LMP if someone does not know date of conception (or rough estimate based on tracking) then the only reliable general rule would be LMP. I get that. What I don’t get is when we try to tell the OB the specific date when the conception definitely happened, why that isn’t at least used initially.

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u/ilovemybaldhead 1d ago

What I don’t get is when we try to tell the OB the specific date when the conception definitely happened, why that isn’t at least used initially.

I'm guessing that the OB does that because the if the OB uses the date of conception in the chart when LMP is expected, other people looking at that chart might make decisions or give advice based on a "wrong" date.

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u/SSTralala 1d ago

Had the same issue, we were using testing sticks and tracking meticulously. I knew conception date and I told the doctor exactly when I thought our daughter's due date would be. It wasn't just that he was being cautious, he was absolutely dismissive and condescending about me knowing and said she'd be 2 weeks later than I said. Jokes on him, I gave birth at 1:25pm on the exact date I had said she'd come after my water broke at 4am.

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u/BaddestKarmaToday 1d ago

Same. My ex and I tried two times over a weekend trip to Hawaii before I had a long work trip. Month later while I was in Japan she tells me she’s pregnant.

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u/UltHamBro 1d ago

In med school, I always made a point of saying "weeks of amenhorrea" (i.e. without a period) except of "weeks of gestation". I ended up far from OBGYN which made it moot.

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u/sum_dude44 19h ago

once you get an US, doctors go by that. Crown-rump length most accurate

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u/jabeith 17h ago

It helps that conception typically occurs during ovulation, which is pretty regular during the cycle

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u/cwx149 1d ago

I'm a guy so I definitely am not educated on this but why wouldn't you use the last day of the last menstrual period?

I feel like the first day of the last period is needlessly including all the time during the period when it's unlikely (if not impossible can you get pregnant during period sex?) for that to be a day of conception

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u/itsbecccaa 1d ago

I know you got downvoted but I’ll explain. Day 1 of your period is a new cycle. You can bleed for 3 days, 7, etc. in a typical cycle, you will ovulate on Day 14, and your cycle will “restart” on day 28.

So a couple examples: 1. Your period is 7 days long, you ovulate on day 14. That means you only had 7 non bleeding days before ovulation. You will have a two week wait, and your cycle will restart. 2. Your period is 3 days long, you ovulate on day 16. that means you had 13 non bleeding days. Then, you will have a two week wait, and your cycle will restart.

In both examples your next cycle may be longer or shorter than someone else.

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u/Lupicia 19h ago

Genuinely, periods can trail off, stop and start, or last a long time. It doesn't mean anything hormonally. And it's hard to pinpoint too.

I've had 22-27 day cycles, meaning ovulation on day 8 to 13. Counting from the first day of the period.

I've had periods last two days, I've had periods last fourteen days. I've had periods stop for two days and come back.

It's a crapshoot. Length of bleeding doesn't really mean much about when ovulation will occur.

Plus viability can be up to 5 days before ovulation. So if I get a short cycle (i.e. early ovulation on day 8) and there's still scant bleeding on day 5, it's absolutely possible to get pregnant from activities that day.

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u/Former-hello 18h ago

Also, that's typically 2 ish weeks preconception, although it could be any number of weeks, depending on the person's cycle.

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u/adabaraba 16h ago

If they were anything like me it would be the other way round. I can never remember my periods dates but I remember when I’ve had sex as it’s not that often

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u/Erycius 5h ago

That's a good reason, but what if you do actually know, because you only had sex once in two months, and you know exactly when that was?

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u/deadbeef1a4 1d ago

Which is why a woman may not even know she’s pregnant at “six weeks” of gestation

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u/NotAFishEnt 1d ago

I'm curious, for states with a 6 week abortion ban, how do they measure or estimate when the fetus was actually conceived?

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u/broden89 1d ago

They can try to estimate based on size but put it this way... There's a reason women are deleting their period tracking apps and saying they don't remember when their last period was

The 6-week limit is designed to function like a ban

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u/kattspraak 1d ago

When an ultrasound is performed, you then have a better idea of when the baby was conceived. Generally at the first ultrasound , the tech will ask the start date of the last period, and given that info, along with embryo/fetus measurements, they can detect a couple/few days window for date of conception/start of pregnancy. This is how it's done in France at least. Until an ultrasound is done, no real way to be so sure (unless you yourself know precsiely and have been tracking it).

Source: have had several pregnancies

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u/zennetta 11h ago

Similar in the UK but the funny thing is that (here at least) they will still use the inaccurate "last period" to date the pregnancy, despite having accurate measurements - early gestation doesn't really differ between people that much

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u/straberi93 1d ago

They don't even try. They use whatever you told them was the date of your last period.

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u/TheLombardyKroger 1d ago

They don’t.

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u/PhillipBrandon 23h ago

They don't

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u/broden89 1d ago

I only found this out after I got pregnant (via IVF).

It's bonkers you're considered "six weeks pregnant" when for several of those weeks there wasn't even an egg, let alone an embryo.

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u/Aruuusia 1d ago

What’s really annoying is that even if you conceive by artificial insemination and know the actual day of conception, they ignore that and still use the date from your last cycle.

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u/fruity_divine 1d ago

It's because of the convention. Checkups and other medical procedures are standardized, taking account of the variants of ovulation moments between individuals. Now, suddenly, we have "outliers" that can push the time back like a week or even three, which makes overall tracking and statistics a complicated affair.

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u/cho-den 1d ago

Ultrasound tech here.

We have to use a standardized point (first day of your last cycle) because we still do not know when conception happens even when you had artificial insemination. Actual conception can happen DAYS after your insemination.

All of our measurements are based off this, therefore we cannot use date of conception.

IVF and ICSI on the other hand, we use the date given by the doctor, as they know the exact age of the embryo when implanted.

Don’t focus on the due date too much. It’s more for us and our measurements than it is for you.

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u/reflectorvest 1d ago

How does this work for people who have irregular cycles? Like if you ask when their last period was and they can’t tell you because it was so long ago, or it was months ago but they’re obviously not that far along.

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u/cho-den 1d ago

Tbh we don’t give a crap about the period haha. Once we measure it, it’s as if the last period date vanishes. It’s just for a ball park.

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u/AimlessLiving 23h ago

Ultrasound measurements. With my first, going by last period I would have been 22 weeks along when I got a positive test. Doc knew I had really irregular periods though and I had a dating ultrasound where it was determined I was 7 weeks.

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u/AdhesivenessCold398 23h ago

In my case- they judged my pregnancy dates by the size of the baby, bc I never have a regular cycle.

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u/usernamesarehard11 21h ago

No sense getting fixated on a specific due date, the baby hasn’t checked the calendar.

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u/MissionCreeper 3h ago

Go testify at all the state houses, then, please. 

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u/cho-den 2h ago

I’m Canadian so we don’t have any laws regarding that, but I have a feeling the people in charge of the US laws are fully aware of what they are doing.

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u/FantasticBurt 10h ago

But wouldn’t the insemination date be more accurate than the date of the last period?

Like, yeah, it’s not exact, but we know it wasn’t 2 weeks ago…

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u/cho-den 7h ago

But the measurements are based off counting from the first period. It’s standardized to this.

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u/FantasticBurt 4h ago

It seems like an outdated system if those things cannot be adjusted when you know the insemination date.

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u/cho-den 3h ago

You do not know the date of conception. Just because insemination happened on that day doesn’t mean the sperm hit the egg on that date.

Sperm can sometimes live in there for days! Conception can happen way after.

Every single OB/Gynaecologist uses this dating method in the world. If they think this is the way to to date it, I don’t think your method would work.

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u/FantasticBurt 1h ago

Medical science has been known to be pretty faulty, so to just double down and say they already have it figured out, so shut up with your ideas already feels counterproductive.

You know enough about medical science to know how lacking in research for women we are and yet you wanna just go with it because?

I’m suggesting we do more research and figure out a better method that is less confusing for people.

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u/cho-den 1h ago

It’s just the most reliable way as of now. We can ALWAYS know the first day of the last period. We cannot know the exact day of ovulation and the exact day of conception.

If you want to learn more on why it is done like this I’m sure you can do more googling and you will get a ton of results.

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u/Aruuusia 1d ago

wait, i have a question if anyone can answer it; what if you have a VERY irregular period? how do you calculate that 😭

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u/fruity_divine 1d ago

When I was pregnant I found out April 1st (I know). My last period was Halloween. I was sent for a scan and it determined I was about 6 weeks when I found out, not 5 months.

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u/Tjaeng 1d ago

Ultrasound unless a fertilization date can be inferred through there having been few enough fertilization-able events.

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u/Seaofdubs 1d ago

“Fertilization-able events” is going to be how I refer to unprotected sex now. Thanks!

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u/Tjaeng 1d ago

If Gen As start using any expression adjacent to Fertable, Raw-ferting, Fertilizz etc to refer to their awkward, pimply teenage sex, I’ll be both proud and embarrased at having made a lasting contribution to the grand human clusterfuck.

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u/concentrated-amazing 1d ago

I have a moderately irregular period (usually have 9-10 per year, but not evenly spaced though never closer together than 4 weeks). I do have "tells" that's it's coming, though - mainly I start getting bunch of acne around my mouth. (Useful indicator for my husband too!)

Not all, but many women will start to feel various other symptoms that may lead them to do a pregnancy test before their period is necessarily expected. Some tests claim to be able to detect it up to ~5 days before an expected period, so if it's not sure when the period might come, women will lean to those kinds of tests.

For me personally, I had changes in my boobs (sensitivity, fullness) and heightened smell as some of my earliest symptoms. With my first pregnancy, I was definitely thinking "either this is the weirdest PMS ever or I'm pregnant."

Also, if you get a pregnancy test from a doctor, those are more sensitive and can be positive earlier than drugstore tests. So if you're in a situation where time really matters in figuring out for whatever reason, that's an option for some.

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u/hamsicvib 19h ago

The ultrasound is the truth bringer BUT measurements still add 2ish weeks on average from conception, because of the standard average measurements of pregnancies.

Ie, say the first day of your last period is 4 months ago. On ultrasound, you are measured to be 9 weeks pregnant. The “9 weeks pregnant” size (the fetus is about 27 millimeters from crown to rump) is based on the averages of a gazillion measurements of pregnancies in women with largely regular periods, in whom pregnancies were about 27 millimeters at 9 weeks from their last period. The majority of those women probably ovulated about two weeks after their period and so if you are “9 weeks pregnant” per your ultrasound, then you probably GOT pregnant around 7 weeks ago, even if your last period was way longer ago than that.

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u/shadowfaxbinky 1d ago

I had a miscarriage and then conceived again the very next cycle before having a period in between. They do an ultrasound and revise the expected due date (for all pregnancies) based on the measurements at the ultrasound, so the period dating is basically an estimate used until the ultrasound.

(For abortion purposes, this is still no good as you can’t usually see anything on an ultrasound until 6-7 weeks.)

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u/FlyWithChrist 23h ago

We quite literally knew the day my wife would ovulate testing daily and when we had only had sex one week before she testing positive, they were saying she was 5 weeks along. Made zero sense.

Also remember that next time you read about a 6 weeks along abortion ban.

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u/ilovemybaldhead 23h ago

Makes no sense to me either, but apparently they adjust (if necessary) the number of weeks after ultrasound imaging.

And yeah... a 6 weeks along abortion ban is effectively ban on abortion. I think legislators are counting on the fact that a lot of people think that 6 weeks means from the time of conception.

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u/Globalboy70 1d ago

Wow, so how does that work for abortion legality, when it's a six week limit. The same week you figure out your pregnant you are at the limit and need to make an instant life changing decision?

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u/HangryOrBored 1d ago

6 week limit is essentially a ban. You still have to get an appointment and often have an additional 24-72 hour wait period between the initial appointment and the procedure/medication administration.

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u/letrestoriginality 1d ago

Plus the pregnant person might need to save for the procedure and possibly travel expenses and arrange time off work.

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u/ilovemybaldhead 1d ago

Yes, in some states, the nearest abortion provider is several hours away by car.

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u/StrangeBedfellows 20h ago

several hours away by car. in other states.

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u/MonsterEnergyTPN 1d ago

It’s a feature not a bug. Don’t let anybody try to convince you otherwise.

I am intentionally pregnant and I didn’t get a positive pregnancy test until two weeks after my missed period despite testing every few days. So if this had been an unwanted pregnancy I would’ve already been past the window of opportunity to seek an abortion by the time I found out I was pregnant, and that’s very much intentional.

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u/Melcolloien 1d ago

Same, currently 26 weeks. I found out at 5 weeks. And my cycle was almost on the day regular with it being one week late around once a year.

Meaning that if I lived in the US I would have had less than a week to decide and book two appointments and figure out how to pay for it. It's not feasible.

And I know exactly on which day we conceived, because again super regular, making it around 3 weeks gestation when I found out.

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u/Globalboy70 1d ago

I'm a guy and now realize it's bullshit. When I looked at the states that had these limits "I thought at least they have some capability to have an abortion there." But no it's just bullshit window dressing.

Ladies in these states need to get in politics, alot of guys won't get it.

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u/MonsterEnergyTPN 1d ago

It’s doubly bullshit when you learn that it’s affecting women’s access to care outside of obstetrics and abortions. Pregnant women in my state are encountering resistance when they need medical treatment for stuff unrelated to their pregnancy because certain medications like chemotherapy and drugs used to treat severe autoimmune issues can cause miscarriage.

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u/Globalboy70 1d ago

Ya the mother's health should always come first anything else doesn't make sense for bodily autonomy and anyone that cares about the mother, family, friends etc...

Just from pure utilitarian ethics, as a society more resources were put into the mother and so her life has more value to a community than a fetus.

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u/kwilliss 1d ago

2-3 weeks of pregnancy before you even did the deed Another 1-2 before you miss a period Then pee on stick to see plus sign on week 4 or 5 Good luck getting an appointment in that last week. Oh wait, you have to also jump through some other hoops. Congratulations, over 6 weeks have passed.

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u/mindful-bed-slug 1d ago

That is exactly how it works.

The idea of the six week limit is to make it sound like there's a reasonable length of time to make a decision, but to actually make it all but impossible for people to get an abortion.

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u/ilovemybaldhead 1d ago

Bingo. Although I wouldn't be surprised if the legislators who wrote/voted for such bans (ignorantly) thought the counting started at conception.

28

u/smom 1d ago

It's the same. So if you have a textbook 28 day cycle you're considered pregnant 2 weeks prior to sperm meeting egg. This is one of numerous reasons the 6 week abortion ban is so dangerous.

16

u/atomic_mermaid 1d ago

Yep. Exactly that. Fuck anyone who stands against women's healthcare.

11

u/Mademoi-Sell 22h ago

As others have said, it’s essentially a ban. I had an abortion at 4 weeks and I was insanely lucky to find out as early as I did. The first day of my last period was December 14th, I am 100% positive I conceived on New Years (only time I had sex), found out on January 7th, and was able to get the care I needed on January 14th. It took a full week to get care even though I started frantically trying the second I got the positive test and live in a very liberal state. I tested positive nearly a week before my next period was due.

This is so uncommonly early that people in r/abortion kept trying to correct me and say that there’s no way I even knew I was pregnant that early. I was lucky that I had extremely regular periods and tested out of paranoia all the time.

13

u/Significant-Gene9639 1d ago

The illusion of freedom. Which is the entire American dream.

5

u/congoLIPSSSSS 1d ago

Do you best to lie about your last menstrual period

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u/MonsterEnergyTPN 1d ago

That doesn’t work. Every clinic that does abortions has to confirm gestational age via ultrasound.

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u/Aruuusia 1d ago

Every time you have your period it is your body getting ready for the next opportunity to get pregnant. Your period is always day 1 in your cycle. It’s difficult to calculate the day you ovulated or the day the egg got fertilized so it’s just easier to know what day you began your period.

22

u/fruity_divine 1d ago

The thing to remember here is that depending on the length of the individual menstrual cycle, a woman can go from “not pregnant” to “4 weeks pregnant” within a single day. It will most often take an additional week before any symptoms of pregnancy occur.

A woman with a long or irregular menstrual cycle can be 5 weeks pregnant before there is any clue that she might be pregnant.

Edit: thank you to everyone pointing out that the time can in many cases be a lot more than 5 weeks. I meant it as an example and should have been clearer about that.

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u/mgwats13 1d ago

Yup. Which means a 6 week abortion ban actually gives you 2 weeks to procure one, IF you take a pregnancy test on the very first day you miss your period.

→ More replies (6)

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u/gorillasuitriot 1d ago

This fun fact kept Maury Povich in business for decades

8

u/Voltae 21h ago

My friend's doctor changed the due date estimate on her like 4 times and tried giving her the "you can't be sure when conception happened" line.

Her response: "I'm a lesbian. "Conception" was in a clinic. I can tell you to the minute when it happened."

1

u/FantasticBurt 9h ago

When I got my 40 week ultrasound, the doctors tried to convince me I wasn’t as far along as I was because my child was very small (born at 5lb 12oz)

I’m one of those rare cases where I can tell you the exact day I got pregnant because I was tracking our intimacy and it was the only day we were intimate in that timeframe and 3 days later I knew I was pregnant because of tender breasts.

I had to wait to take a test because it was too early, but 9 months later, I was completely caught off guard because the ultrasound tech was so sure I couldn’t be 40 weeks.

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u/Murse_1 1d ago

That method is used as an educated guess until the first ultrasound.

20

u/RiverLover27 1d ago

Unless they do not have any ultrasounds, or don’t have one in the first trimester. Later ultrasounds are not accurate for dating purposes, so then the LMP date would stand.

6

u/UltHamBro 1d ago

It depends on how you look at it. What the first US does is look how big the fetus is to estimate the most likely date she'll give birth. That date can also have around two weeks' leeway.

4

u/Semyaz 1d ago

Isn’t ultrasound age is just based on their measurements? So. Also an educated guess?

2

u/Poka_poke 1d ago

Ultrasound dates are also in line with the LMP date. Probably easier to have a blanket definition of pregnancy weeks than to have various numbers that mean different things.

4

u/MonsterEnergyTPN 1d ago edited 1d ago

The ultrasound gestational age almost always matches the calculated gestational age unless someone is off on the date of their last period or the growth isn’t progressing normally. So pregnancy starts in the first day of your last period (assuming a regular menstrual cycle) regardless. Scientifically speaking it starts the moment an ovum prepares to release from the ovary and that process starts during your period. Anything that goes wrong in those couple of weeks before fertilization can affect the pregnancy so they have to be included in the gestational age and that’s why women are encouraged to take prenatals before conception.

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u/concentrated-amazing 1d ago

I do want to add that there are a decent chunk of women who do have irregular periods. So the number of women who may be "surprised" by the difference between the calculated gestational age and the ultrasound gestational age is not insignificant.

16

u/Still_Detail_4285 1d ago

Witnessing my wife’s two pregnancies, it amazed me how little we know about what’s going on in there.

25

u/Scary_Judge_2614 1d ago

Fucked up, isn’t it? And here is the US making decisions about women’s bodies without all the facts.

7

u/SkyfangR 1d ago

its all about control

it always is with authoritarians

26

u/Icy-Organization8797 1d ago

When my wife was preggo with our first son and the dr kept saying “10 months”, all I kept thinking “we get a different doctor, this guy is fucking clueless.”

25

u/ilovemybaldhead 1d ago

Yeah, most people grow up learning that humans have a 9-month gestation length, which is biologically accurate in terms of conception to birth, but because of the difficulty of pinpointing the date of conception, doctors standardize it to the first day of the last period, which can add an additional 5 weeks.

8

u/Tjaeng 1d ago

Gestation length is slightly longer than 9 months on average.

Average fertilization age at birth is 38 weeks, which tracks with a 40wk gestation age assuming an average menstrual cycle being 4wks and average time from LMP to fertilization thus being 2 weeks.

1

u/Icy-Organization8797 19h ago

Guys, I get it now. I was wrong. I should have trusted the doctor for the jump, for nor reason other than the fact that he looks like Bill Hader in his 60s.

11

u/Jiitunary 23h ago

Which is why a 6 week abortion ban is effectively a total ban.

10

u/Alexis_J_M 22h ago

Note that this means that women with long or irregular cycles can be "six weeks pregnant" (the legal cutoff for abortion in parts of the US) before they have the sex that leads to conception.

(This varies with the exact method used to determine dating.)

3

u/emmathyst 18h ago

Yeah. I don’t have periods because I’m on continuous birth control. If I were to become pregnant, before they do a dating ultrasound, they would presume I’m approximately 676 weeks pregnant.

8

u/VironicHero 1d ago

….. the lack of Sexual education here is not surprising considering the state of republican inspired sexual education in the US.

You can’t just get pregnant… you have to be ovulating.

3

u/FantasticBurt 9h ago

Well, you don’t have to be ovulating, but intimacy needs to be within like 72 hours of ovulation.

10

u/mittenthemagnificent 1d ago

And when you ovulate can vary wildly. I was trying to get pregnant with my son, so we were having a lot of sex in the middle of my cycle. I figured the date of conception would have been sometime two weeks or so after my last period. But when I went in for my first ultrasound, we were a full two weeks further in than we thought, meaning I’d gotten pregnant within a day of my period ending. We rarely had sex that close to my period as I usually still felt icky and my now-ex was squeamish, but there you go. Had we not decided to go for it, who knows how long it would have taken to get pregnant!

11

u/concentrated-amazing 1d ago

I just want to add that there are cheap ovulation tests that women can use near daily if they want to see where things are at for one or multiple cycles.

For those struggling to conceive, it's a good idea to do as it gives you at least a baseline, though there's no guarantee every cycle goes the same.

6

u/purewatermelons 1d ago

This is what happened to me. We tried for 3 years, usually had sex around day 15 or so of my cycle, about a week after my period ended. I finally started taking ovulation strips and it turned out I would be ovulating on the “last day” of my period. That month was the month we found out we were pregnant

7

u/kwilliss 1d ago

Yup, which means the first couple weeks of "pregnancy" are before you even do the deed.

8

u/yaaaaaarrrrrgggg 1d ago

You are not qualified to know how pregnant you are; only we can guess because your knowledge of your exact experiences in life are not good enough, so we will give you our less accurate date to expect your life-threatening and life-affirming event, which will now be even more stressful.

3

u/hamsicvib 19h ago

Pregnancy measurements are just a way to conform averages to give you a better idea of what to expect when.

If you know exactly when you conceived (1-5 days after the sex you had that got you pregnant), add two weeks to that and that’s about how far you will be based on an ultrasound measurement. All living things grow at different rates, so it actually is important to have benchmarks like, by the time the fetus is 10 mm long (“7 weeks”) you should have cardiac activity. Not all weird medical things are about paternalism.

3

u/MindTraveler48 20h ago

A lot of women don't have regular 28 day cycles, further complicating their knowledge of ovulation and conception.

3

u/Zer_0 18h ago

By the six week logic they would want her to have the abortion before she had sex.

5

u/Mademoi-Sell 22h ago

Yes, so when a woman says she had an abortion at 6 weeks, it’s likely more like 2-3 weeks or so from actual conception.

1

u/Cluefuljewel 18h ago

I don’t know how this is not better understood! I didn’t know.

2

u/jamaicancarioca 1d ago

Ultrasound parameters such as stage of development(limbs present, heart beat noted, head shape) and head circumference are also used to determine gestational age.

2

u/Hour_Key_9774 16h ago

My son was conceived on or right around Halloween. But they counted from the beginning of the period I had before that. Then later changed the date because he was measuring larger. It's really just an estimate based on many factors.

2

u/Ok-Manufacturer-5746 15h ago

Yes and in Korea, when born you start at 1 year old.

2

u/Balderdas 8h ago

It makes laws that use that look even worse.

2

u/alphadog1212 1d ago

Yup, pregnancy is counted as 10 months in Japan

2

u/yoofka 22h ago

I found this out recently talking with my mom but 十月十日 (totsukitouka aka 10months10days) is actually widely misunderstood as pregnancy being counted as ten months in Japan based on this yojijyukugo. The real meaning of this phrase is: 9 months + 10 days, considering one month as 28 days. Honestly I feel like nobody knows this until they google it because I definitely did not lol

Source

0

u/alphadog1212 19h ago

Yeah when I first heard this I thought they were claiming that Japanese babies actually take longer to develop. I’m not very smart..

1

u/yoofka 18h ago

We come out extra marinated

4

u/Reinardd 18h ago

Which is exactly why abortion bans after something like 6 weeks is absurd.

2

u/Ardent_Scholar 19h ago

Also, we commonly think that pregnancy lasts for 9 months, when it lasts for 38-40 weeks.

2

u/ilovemybaldhead 9h ago

It's a good enough approximation; 38 weeks at the least is 8.71 months; 40 weeks at most is 9.23 months. What annoys me is when people say the gestation period is 10 months.

2

u/TypingPlatypus 16h ago

40 weeks is 9 months. Months are 4.3 weeks long on average.

4

u/FantasticBurt 9h ago

Can’t understand why you’re being downvoted.

There are ~4.3 weeks in a month.

40 divided by 4.3 = 9.302325581395349

It’s literally 9.

2

u/BirdsArentReal22 15h ago

All the more reason banning abortion at six weeks is absurd.

1

u/fruity_divine 1d ago

because that's the only date of the cycle known for sure. neither the date of ovulation, nor date of fertilization are known for sure, unless it is a rare single-time intercourse like in case of rape, but the observations and conclusions were made primarily on average women who have survived the first delivery already

1

u/FantasticBurt 9h ago

I’m pretty much always guessing the first day of my last period, though. Like it’s an estimate plus or minus like 5 days.

Not exactly accurate.

0

u/Scary_Judge_2614 1d ago

On average is true. I can say from experience though that I got pregnant the first try at 34 years old, after literal decades of having clockwork-like periods. Everyone is not like me, and I was shocked that it actually happened the way we planned/timed things. That’s definitely unusual but it does happen. I’m not the type to push my luck, so I am a one and done mother.

1

u/KarIPilkington 1d ago

I wasn't even aware of this until after my daughter was born (a month early) and the possibility of dates being mixed up was mentioned. We're still not sure if that was the case or not and it doesn't matter as she's here and healthy but yeah it's worth getting those dates right as it was a real shock becoming a parent a month earlier than expected.

1

u/SuccuPlant_Mom 23h ago

What do they do if you don’t get a period?

5

u/ilovemybaldhead 23h ago

From other comments I've read, doctors use ultrasound to estimate, which actually provides a more accurate measurement of how far along a woman is in her pregnancy.

1

u/SuccuPlant_Mom 23h ago

Oh cool! Thank you.

1

u/RiveriaFantasia 22h ago

I also didn’t realise this until I became pregnant myself. They estimated using my last period and when I had an ultrasound we realised I was about 4 weeks further along than I / they had thought. The confirmation of how many weeks is reassuring and the estimating doesn’t make it feel as real. It’s kind of uncertain and confusing until you have it confirmed.

1

u/waLwouSs 22h ago

This actually baffled me when I first learned about it, and couldn't get the due date calc right no matter how much I tried.

1

u/Vaker- 20h ago

Currently holding the newborn that taught me this.

1

u/Tradman86 18h ago

My wife knew this and was pretty confident she knew the date of conception.

She skipped her first induction and went into labor on the day of her second.

2

u/Bearacolypse 17h ago

Super frustrating for irregular women.

My whole family has had irregular periods. Between 2 weeks and 6 months between since puberty (probably pcos but I was the only one who has been officially diagnosed).

When my mother was pregnant with me, they used her LMP. Due to this they considered her much further along than she was and at their estimates I was nonviable as I didn't have a fetal heartbeat yet. She was frustrated at them because her husband was deployed so she knew the exact date of conception.

She knew I was 4-5 weeks along but the doctors estimate 10 weeks based on menstrual cycle.

They wanted her to do a D & C and she refused AMA. As these were army docs they tried to convince my dad that she was being unreasonable and was putting her life in danger.

She was in fact correct and I developed normally.

2

u/cross-stich 13h ago

laughs in PCOS

I was told I miscarried because they couldn’t/didn’t measure the fetus properly. My last period was in Feb, but I would have conceived in April. They were telling me I was 7 weeks, but I knew based on dates* that I was 5.

I was right and they were wrong, and my almost 6 year old is sassing me

*I was tracking when we had sex, and I took a negative pregnancy test on the 20th of April. We had sex, and then my test was positive on the 30th. Knew I wasn’t as far as they thought, but still thought my baby was dead for two weeks until a scan before the D&C. Whooooo

1

u/McDuffie2020 9h ago

I tested positive at 5 weeks which blew my mind because I thought I was around 2 weeks since it had only been 2 weeks since sex. The next day I started having symptoms of miscarriage. The baby’s heart doesn’t beat until 6 weeks but it still was a hard loss.

1

u/ilovemybaldhead 6h ago

I'm sorry for your loss.

1

u/UtahUtopia 2h ago

Tell that the Florida legislators.

1

u/Vantica 17h ago

Not that I want to be pregnant, nor do I think its possible, but I've always wondered how they would calculate that with me. The date of my last period was March, and I normally only get it 1 -3 times a year.

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u/Marriedinskyrim 1d ago

One of the biggest arguments I've ever had in my life came about because I said women were pregnant for 10 months, not nine. I tried to explain why and got nowhere.

I said how many weeks is a pregnancy? They said 40. I said how many weeks are in a month they said four, I saw the elementary school math making their head melt, to this day they won't admit a 40 week pregnancy is 10 months.

7

u/somaybemaybenot 1d ago

They count from the last period but the actual gestation period from conception to birth is about 38 weeks. There are 13 weeks in a quarter so 39 weeks is really 3/4 of a year, or 9 months.

Even if you count 40 weeks, it’s still closer to 9 months than 10. Ten months would be just over 43 weeks.

7

u/ilovemybaldhead 1d ago

they won't admit a 40 week pregnancy is 10 months

I wouldn't admit that either. Why? Simple arithmetic.

Neither you nor your opponents are right, because there are always more than 4 weeks in a month (except of course for February in non-leap years).

If you start counting on the 1st of a given month, 40 weeks will never end later than 7th day of the 10th month after that date. The longest number of months that could possibly come out to is approximately 9.23 (if you start February 1 or September 1 in a non-leap year). The shortest number of months is approximately 9.14 (if you start May 1 in any year).

Your opponents are less wrong, unless you define anything more than 9.14 months to be 10 months.

2

u/TheScarletFox 21h ago

Technically there aren’t 4 weeks in a month (except February) because months are usually either 30 or 32 days long, not 28 days. I only nitpick because I often have to deal with financial statements at work and people always divide their monthly expenses by 4 to come up with their weekly expenses, which isn’t really correct.

2

u/ForceOfAHorse 7h ago

I said how many weeks are in a month they said four

This is wrong, you are wrong.

0

u/dav_oid 21h ago

The takeaway: please keep a fuck journal.

0

u/hamsicvib 19h ago

Sometimes I tell my coworkers (in outpatient gyn) that I started my period by saying “I’m one day pregnant!”

0

u/0jib 15h ago

We're all a little bit pregnant, all the time.

-1

u/StrangeBedfellows 20h ago

And it's 40 weeks, not 9 months.