- Old wives' tales, you know 'em, you love to repeat 'em,
but are any of them actually true?
I'm Mama Doctor Jones,
a board-certified OBGYN and mom to four.
And today, we're going through seven old wives' tales
that are common to pregnancy and birth,
and seeing if any of them actually hold up to the science.
This is actually the first video I am filming
since we hit a million subscribers, which is wild to me.
I'm still in shock. It's, how did this happen?
Thank you so much.
I am so proud of this channel, where we came from,
where we're going, and all the good we have done here.
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Let's jump in to the video.
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An old wives' tale is basically a word-of-mouth superstition
or urban legend that has been passed down
through folklore from generation to generation.
And for some reason, a lot of them tend to center
around pregnancy and birth.
So the first one we're talking about today
is that the fetal heart rate is predictive of the fetal sex.
And this is one I hear in my clinic all the time.
I actually hear it both ways.
I will have someone in one room say,
"Oh my gosh, the heart rate is high.
That means it's a boy."
And then in the next room, they'll say,
"Oh my gosh, the heart rate is high.
That means it's a girl."
Nobody can keep it straight what the actual legend is.
Unfortunately, this one has not held up
to the test of science,
at least not in the way that we would expect it to,
based on how people use it
to try to predict the sex of their baby.
So if that's the case,
how does it keep getting passed along?
Well, one, because back in the day,
when all of these started, we didn't have any way
to accurately predict what baby you were having,
and two, it's right 50% of the time,
as are any of these that are trying to predict the sex.
There is actually some very limited data
that says maybe a female fetus
is more likely to have a higher heart rate
during the process of labor and delivery.
And the theory here
is that they just have a little bit of a different reaction
to stress hormones than a male fetus,
but that is only in the final moments of labor and delivery.
That is not going to be very helpful
if we're just trying to guess the sex of a baby,
based on the average heart rate.
There's also limited data
that says a female fetus might mature their heart rate
and the dynamic changes in that heart rate
a little bit quicker in pregnancy.
What that means is, as we go through pregnancy,
you see a fetal heart rate pattern changes a little bit
the further along you get,
and they think maybe a male fetus
is just a little bit slower
to develop those dynamic changes.
You might have a little bit lower heart rate in a male fetus
during the third trimester,
but again, that only comes down
to about one beat-per-minute difference,
which, obviously, is not going to be super helpful
if you're trying to use it to predict the sex of a baby.
It might show up as statistically significant in literature,
but if we're just looking at a baby's heart rate,
that's not going to help us at all.
So unfortunately, I do have to say, this one is debunked.
The speed of a fetal heart rate,
when you go in for that first ultrasound early on,
is not going to be very helpful
in predicting the sex of your baby.
This next one is one that I am certain everybody has heard.
And that is, how much heartburn you have
during the pregnancy is predictive
of whether your baby will be born with hair.
And this one actually has some scientific support behind it.
But the way they studied this one
is actually really funny to me.
They basically got people
to rate their heartburn throughout pregnancy,
and then at the time of birth,
they took two pictures of each baby,
and sent them to independent reviewers
to rate how luscious their locks were.
And the independent reviewers would write that down,
and then they would go back
and compare the heartburn ratings
to the babies' hair ratings.
And what they found
is that people who reported more heartburn
during their pregnancy,
and more severe heartburn during their pregnancy,
actually did end up having babies
who were independently rated
as having more luscious locks of hair on their head
at the time of birth.
In fact, an even more interesting correlation to me in this,
because my babies were born completely bald,
is that 10 of the 12 babies they looked at
who had no or below-average amounts of hair,
their parent had no heartburn at all
during the entire pregnancy.
So what's the theory
behind why this might actually be a real association?
The authors of this notably small, but interesting study
came to the conclusion
that they think it may be hormonally related.
Just to quickly explain,
I think we've talked about this a bunch of times before,
but basically, the lower esophageal sphincter,
which is at the bottom of your esophagus,
keeps acid in the stomach and out of the esophagus.
During pregnancy, changes in your hormones
cause that to be able to open more easily,
letting acid from the stomach into the esophagus.
They theorize that those same hormones would be related
to how well the hair on a baby's head grows.
So they're saying, if your hormone levels are higher,
you're more likely to have reflux or heartburn.
And if your hormone levels are higher,
the baby is more likely to grow more hair.
Who knows? It's really interesting.
Anecdotally, for me, my babies were all bald,
and I had very little to no heartburn during my pregnancies.
But, you know what? I don't know.
I think it's interesting,
and I love using this study to talk about it in clinic.
This is another one you've probably heard
in many different ways.
And that is weight distribution
on the person who is pregnant
is predictive of the sex of the baby.
You may be noticing a theme here
that a lot of these revolve
around predicting the sex of the baby.
This is likely because back in the day,
when these started becoming urban legends
that were passed down through folklore,
there was no reliable way
to determine what sex baby you were having
before the time of birth.
So they came up with these ideas and associations
to see if they could make any predictions.
This one doesn't have any science to back it up either.
So you might've heard people say, "Oh, you're carrying high.
Are you having a girl?"
"Oh, you're carrying low. Are you having a boy?"
Or vice versa.
You might've heard people say, "Oh, your hips are wide.
That's because you have a girl."
You may have even heard it in the way,
not necessarily of weight, but, "Oh, you're glowing.
That means it's a boy."
"Oh, you look tired.
The girl is stealing all of your beauty."
All of these things that people say,
but unfortunately, none of these
have any science to back them up.
The overall determination of where you gain weight
during pregnancy is primarily related to genetics.
The shape of the belly, how high it is, how low it is,
is primarily related to both fetal positioning
and the body type of the who is carrying the baby.
So, I am very short-waisted.
That means that all of my babies
looked like they were up in my lungs
because I had nowhere to grow babies except that way.
My torso is very short.
Someone who's long-waisted
may carry their babies a little bit lower.
It just depends on your body type,
your genetics, and the way the baby's sitting.
If you have a baby that's transverse,
where it's straight across in the abdomen
instead of up and down,
of course your belly's gonna be wider
because the baby is laying
and taking up space in that direction.
So, no science for this one. Sorry to break any hearts.
So, this one is one that actually came up in my clinic
a while back that I had never heard before.
And when I went to look it up,
it turns out this is a common belief
that people have been told by their grandparents
or parents at some point in their life.
So what this person said to me was,
"If I put my hands above my head,
will it actually make my baby's cord wrap around its neck?"
This is one I've now heard in many different forms,
but that tends to be the most common thing that people ask.
And the answer is absolutely not.
What you do with your body has no bearing
on where the cord is around the baby.
If a baby has a cord wrapped around its neck
at the time of birth,
it is most likely because it's rolling around in there
and getting wrapped up in its cord.
In fact, about a third of babies are born
with what we call a nuchal cord,
meaning the cord is wrapped around its neck.
And most of the time,
this does not cause any problems at all.
Certainly, there are rare instances
where this can be very dangerous,
but most of the time, it is really common,
and not that big of a deal.
But none of the time is it ever related
to maternal positioning at all during the pregnancy.
The next one comes also in a variety of fashions,
but the most commonly repeated one I hear
is that if you eat a bunch of bananas
leading up to the time that you conceive,
you're more likely to conceive a boy.
Why would people think this?
Well, actually, this one is, interestingly,
maybe a little bit science-related.
So there's this one study,
which basically came to the conclusion
that a higher-calorie diet in the preconception period
and notably, a higher potassium intake
in the preconception period was associated
with an increased chance of getting pregnant with a boy.
However, I am a little bit skeptical
when it comes to this one, and let me explain why.
First off, we know how sex is determined, right?
It's carried on an X or Y chromosome
that comes from the sperm.
So it makes absolutely zero sense to me
how we would take preconception diet
in the person who is getting pregnant,
and associate that with likelihood to have a boy or girl,
because that's coming from the other side.
Maybe we could look at that in a male,
and whether their sperm live longer,
if they're X or Y, depending on their diet,
but I don't see how this would be related
to maternal diet before conception in any way.
Maybe that would be theorized then,
that instead of it being the likelihood
to conceive a male or female embryo,
it's the likelihood of that embryo to implant.
If that were the case,
I think we would see that in IVF studies.
And I don't know if that's specifically been studied or not,
but I've never seen any data
that would indicate preconception diet is more likely
that a male or female embryo will be the one that implants.
And then, third, these have never been reproduced.
So this is a single study with these findings
that never have been able to be reproduced
by any independent researchers.
And finally, these numbers are really close to 50-50 chance.
They range anywhere from about 46% to 55%,
which is really not that far off from a 50% chance.
So, I have a hard time believing it.
The data is there. It's never been reproduced.
It's pretty close to chance, but we'll leave it at a maybe.
If you've ever worked in a labor and delivery,
or you know anybody who has worked in a labor and delivery,
then you have absolutely heard this one,
and probably even if you haven't.
And that is, full moons cause people to go into labor.
Every seasoned labor and delivery nurse
and obstetrician that I know will die on this hill.
Unfortunately, the science isn't really backing us up here.
There's quite a bit of data to look at on this one,
but most of them are pretty small studies.
One of the bigger studies was a five-year data review.
In this study, they looked at five years worth of data,
and found absolutely no association
with how many people delivered their babies
or went into labor and the lunar cycle that was happening
at the time of that delivery.
That being said, interestingly,
there is some data on barometric pressure drops,
and the association with the chances that your water breaks
or that you go into spontaneous labor.
We see this clinically,
and especially me, living in central Texas,
when there is a hurricane or big storm coming.
Any time people are evacuating from the coast,
we will see an influx of people coming in
with their water broken.
There is some data to support
that these big drops in barometric pressure
that happen in the days or hours leading up to a big storm
could be causing people to break their water
or go into labor at higher rates.
I think it's really interesting.
I don't know that the full moon is actually affecting people
to the extent that we would like to believe
in our superstitious labor and deliveries,
but the barometric pressure drops leading up to storms
is something that we have also all heard
on a labor and delivery unit,
and it does have some science to back it up.
So this is one you've probably heard
in a variety of forms as well,
and that is, looking at something ugly,
particularly an ugly animal, while you are pregnant,
will make your baby ugly.
And while we all know that beauty is subjective,
especially when it comes to newborn babies,
there's no reason to think that something you look at
or think about or do during pregnancy
is going to make your baby ugly.
How your baby looks
is almost solely dependent upon genetics,
and I promise, you're not going to ruin its beauty
by looking at a skunk while you are pregnant.
All right, y'all, I hope that you learned something today.
This was a really fun video to research and make.
If you'd like to watch another video,
I will link a playlist right over here.
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Hit that subscribe button,
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I promise, you will leave with things to tell your friends.
And I will see you next Monday.
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