Pregnancy and Biology 101
I originally titled this “Pregnancy 101 for Guys,” but given the state of sex education in the U.S., I suspect many of us need some additional learning regardless of gender. But I’m mostly looking at my fellow guys with this thing, especially with all of the recent debate and discussion. Some of this is information I wish I’d learned sooner. Hopefully it will be helpful to others.
This is a very incomplete list. Factual corrections are appreciated. And if you’ve encountered additional myths that need busting, feel free to add them to the comments. (I considered just turning comments off, but I’ll leave them open for now and we’ll see what happens.)
Periods can’t be turned on and off like a tap.
I don’t even know what to say to this one, which came from a Twitter thread. But, um…
- Periods happen when the uterus sheds its lining, resulting in bleeding from the vagina.
- Periods generally happen about once a month, and last for about 5 days. Neither of these numbers are exact.
- For some people, periods are relatively regular and predictable. For others, not so much.
- No, it’s not like peeing. You can’t just “hold it.” WTF is wrong with you, man?
Fertility is cyclical.
About halfway through the menstrual cycle, the ovary releases an egg into the fallopian tube. That egg lives about 12-24 hours after leaving the ovary. If it’s not fertilized, the egg dissolves, and the cycle continues.
This doesn’t mean there’s only a 12-24 hour window when sex can result in pregnancy. Sperm can survive up to five days in the fallopian tubes. If you and your partner have sex, and your partner ovulates two days later, that’s when sperm and egg would potentially meet. In other words, fertilization would occur two days after you had sex.
(This should also help explain why some emergency contraception works by preventing ovulation after sex.)
Conception isn’t instantaneous.
“It can take anything from 45 minutes to 12 hours for a sperm to reach your fallopian tubes, which is where conception usually happens.” (Source)
And once the sperm reaches the egg, “it takes about 24 hours for a sperm cell to fertilize an egg.” (Source)
“X Weeks Pregnant” isn’t the number of weeks from conception.
“Gestational age is the common term used during pregnancy to describe how far along the pregnancy is. It is measured in weeks, from the first day of the woman’s last menstrual cycle to the current date. A normal pregnancy can range from 38 to 42 weeks.” (Source)
In other words, someone who is “six weeks pregnant” has not actually been pregnant for six weeks.
Pregnancy tests don’t work instantly after conception.
“If you are pregnant, your body needs time to develop detectable levels of [human chorionic gonadotropin (HCG)]. This typically takes seven to 12 days after successful implantation of an egg.” (Source)
Healthline advises waiting until the week after your missed period for an accurate pregnancy test result.
If the average menstrual cycle is 28, and gestational age is measured from the first day of the last menstrual cycle, this means you’re already considered to be a minimum of five to six weeks pregnant by the time you get an accurate result from your pregnancy test.
Conception =/= Pregnant.
“Conception doesn’t always mean that a pregnancy will occur and be carried to full term.” (Source)
The American College of Obstetricians and Gynecologists notes, “Fertilization, the union of an egg and a sperm into a single cell, is the first step in a complex series of events that leads to pregnancy.” (Source, Emphasis added)
It takes around a week, give or take, for the fertilized egg to implant in the uterine lining.
Whether you agree or disagree — and I have no doubt people will continue to argue this one — the ACOG has stated that “pregnancy begins upon the implantation of a fertilized egg into the lining of a woman’s uterus. This typically takes place, if at all, between 5 and 9 days after fertilization of the egg – which itself can take place over the course of several days following sexual intercourse.”
What is ectopic pregnancy?
In some cases, the fertilized egg implants outside of the uterus, most often in the fallopian tube. “The fertilized egg can’t survive, and the growing tissue may cause life-threatening bleeding, if left untreated.” (Source)
The incidence of ectopic pregnancy is 1-2% in developed countries. (Source)
Ectopic pregnancy is treated with either medication or surgery to prevent the development of the fertilized, implanted egg, in essence terminating the pregnancy.
Pregnancy can be dangerous. Especially in the U.S.
“With an estimated 26.4 deaths for every 100,000 live births in 2015, America has the highest maternal mortality rate of all industrialized countries—by several times over.” (Source)
“African-American, Native American and Alaska Native women are about three times more likely to die from causes related to pregnancy, compared to white women.” (Source)
We have got to do better with health care, people…
May 19, 2019 @ 8:46 pm
Thanks for this, Jim.
May 19, 2019 @ 8:47 pm
A note on ectopic pregnancy, since apparently it’s being bandied around the Ohio legislature, you CANNOT remove and reimplant an ectopic pregnancy into the uterus.
May 19, 2019 @ 10:10 pm
You might want to note that a menstrual cycle is measured from the first day of one period to the first day of the next period. That’s important for figuring out *approximately* when ovulation happens – if the cycle is 28 days long, and the period is 6 days, then ovulation will *probably* be about 6-9 days after the end of the period. (I had a guy tell me once that I couldn’t possibly get pregnant by having unprotected sex right then because I wasn’t bleeding – so I wasn’t fertile!)
May 19, 2019 @ 10:17 pm
Thank you for this, Jim. The current level of debate over abortion is so incredibly uninformed…. perhaps on purpose. It’s like people don’t really want to know how complex the process is. They want to simplify it and make it all easy to judge. Life is never like that.
Best to you and yours.
May 19, 2019 @ 10:34 pm
I can’t believe that there are so many people who don’t know these basic facts. (Among others.) The ectopic pregnancy one blows my mind. “Transplant it into the uterus” is an insane and dangerous misconception.
This whole discussion is driving me mad. Thank you for injecting a note of sanity.
Eleanor C Ray
May 19, 2019 @ 11:25 pm
Another note about conception–a woman *may* become pregnant from sex during her period, or at any other time in that month-long cycle, as there is a variable delay in women, even in the same woman, between each of the steps in that cycle. Asserting (not you, Jim, I presume you know this) that ovulation occurs at [a to b] number of days is too simple, as it must be remembered that the *average* dates are not the *only* dates, and that even healthy humans vary widely from the “average” of the species. (For example: Me! I was conceived the 27th day after my Mom’s last period started.)
The point I really run into trouble with a lot of glib opinions is when they are asserted as though because it happened one time, we can legislate that it will always happen that way. We can imagine you ought to be able to theoretically make something work once under the perfect set of circumstances, therefore we can legislate it, because “a woman can just do that, right?” From “heard of it once”, straight to “must be repeatable”!
No two people are alike, things that work for one don’t always hold true for another, and legislation should not be made based on “I heard about this in the locker room, it is totally real, right?”
May 20, 2019 @ 12:39 am
A person with a uterus — and do let’s remember that not everyone who has one is a woman, and not all women have them — can also ovulate more than one time per cycle or while already pregnant, which is what leads to getting pregnant while menstruating, and situations like a friend of mine who was conceived six weeks before her twin brother.
May 22, 2019 @ 9:00 am
I suspect a lot of the ignorance expressed by the forced-birth advocates is more strategic than genuine. Becker in Ohio, for instance, says he has no idea what effect his “no insurance coverage for abortion” will have on contraceptive coverage, but he’ll leave that to smarter people. Possibly he’s that dumb; possibly he’s playing defense (honest, he had no idea it would be interpreted to ban the pill and IUDs, and that someone wouldn’t instantly invent alternative methods! He’s no doctor!).
Likewise I suspect his claims about ectopic pregnancy are less moronic and more about pretending that ectopic pregnancies are viable.
May 22, 2019 @ 11:45 am
I would add to the ectopic pregnancy section that is is essential to terminate ectopic pregnancies, they can not come safely to term. And by that I mean they are extremely likely to kill the woman if untreated. *graphic detail*
*I mean it*
When there is no more room in the fallopian tube where the placenta is attached for the growing placenta and foetus the fallopian tube will will burst, the placenta has an extremely good blood supply, there is a high probability that the woman will bleed to death.. The earlier they are aborted the better as there may be the possibility of saving the fallopian tube and therefore half of the woman’s fertility.
If your fallopian tubes are sufficiently damaged you can’t get pregnant without IVF, been there, done that, doesn’t always work and didn’t in my case. However I was thoroughly educated about the dangers of ectopic pregnancies as having IVF can put you at higher risk so they want you to be alert to the possibility, so they can abort it before you risk bleeding out.
May 24, 2019 @ 10:25 am
And this twitter thread, reposted on Bored Panda is also worth a read for the *ridiculous* things some folks (mostly dudes) believe about reproductive anatomy: https://www.boredpanda.com/dumbest-thing-man-said-to-women-reproductive-health-menstruation
May 28, 2019 @ 5:45 pm
I see MadGastronomer beat me to the ‘more than once per cycle’ comment. This was actually significant news when I first saw it several years ago, and was brought up with ‘this is (at least part of) why the rhythm method seems to work reliably for some people, but fails utterly for others’.
The fact that this was news when I first read about it (within the last 25 years or so, anyway) is in and of itself a bit of a damning statement about how well even the medical profession pays attention to such things.