“Fifth grade”

“Seventh or eighth grade”

“High school”

“High school, but that feels late to me.”

I asked a bunch of my coworkers when they first had the talk.

Not like the sex talk, but the talk about how babies get made from a scientific perspective.

“Honestly, for someone who just successfully gestated and delivered a human baby, I know

an embarrassingly little amount of, like, how my egg was fertilized.”

Even if we don't remember it super well, we were likely taught it. So...how does fertilization work?

“Oh, God, okay”

ummm....

“So, sex happens”

“After the ejaculation happens”

“The little sperm swimmers kind of like to do, do do, do do like”

“Many, numerous sperm”

“It's a bunch of them swimming up there”

“They're like going really fast”

“Um”

“There are so many that are, like, looking for the egg”

“It's weird because I feel like you don't really hear about the egg.”

“The egg is very passive and just like 'Ehhh, fertilize me.' And like the sperm is like

the one doing all the work.”

Everyone I talked to told me similar stories that all had a lot of holes.

And it might be because of what's inside these.

Right, so it's all been modeled off this fairy tale where you have the knight in shining armor

going to save the damsel in distress.

I think most of us have heard some version of that story. And it's just... it's not true.

It's not factual.

Nadia Johnson and Lisa Campo-Engelstein co-wrote a paper about how the fertilization story

we're taught often centers on the male perspective.

In it, they analyzed popular textbooks used from middle school to medical school — keeping

an eye out for gender-biased language.

I ordered some of them on eBay.

This book describes only the sperm's role in fertilization:

“300 million sperm are released...some are attacked...and many simply die along the way.

Only one sperm can fertilize an egg.”

In other textbooks, the female body's role is described using only passive language:

“If an egg is present, there's a good chance of it being fertilized.”

Or “If an ovum is present, the sperm swarm around it and penetrate those layers.”

The books show the sperm actively swimming, surviving, and penetrating while the egg just...sits

there.

It's sending these really problematic messages about what it means to be male and female

and who has agency and who is passive.

The truth is, fertilization involves two equally important reproductive systems collaborating

in an awesome two-player adventure.

Real quick before we start: There are different ways of making babies for different types

of people.

In this video, we'll be focusing on the fertilization story between male and female

reproductive organs.

That story starts with the egg's journey, beginning in the ovaries.

Once a month, during ovulation, a mature egg bursts out of the ovary.

A finger-like membrane at the end of the fallopian tubes scoops that egg up.

And other membranes pull it toward the uterus.

It's a complicated, necessary trip.

And for the best chance of fertilization, millions

of sperm enter the vaginal canal around the same time.

Some go in the complete wrong direction, and it's game for them over early on.

The ones that go in the right direction encounter

a more acidic environment than they're used to.

That acidity in the vaginal canal can harm a few sperm, but the seminal fluid they're

ejaculated in acts as a sort of shield potion, protecting them.

And while some textbooks describe parts of the female reproductive tract as a place that

sperm never make it out of, or are attacked by...

They don't talk about the ways in which the female body actually helps.

After the sperm travel through the vaginal canal, they enter the cervix.

The environment of the cervix can be really helpful.

It enables the sperm to survive for a little bit longer

and then it facilitates the migration of sperm.

Then sperm swim rigorously towards the egg, but...let's just say that they're not

Michael Phelps.

It has this tail and you think, oh, this tail must be responsible for it swimming from

the cervix basically to the egg.

We know now that most of the motility is because of the things that the uterus and the female

reproductive tract is doing to move the sperm along.

First, during ovulation, the thickness of the fluid in the cervical canal is thinned

out.

Then, the muscles of the uterus contract, propelling the sperm faster than they could

ever swim, toward the fallopian tubes.

At the same time, the egg is releasing a chemical signal that acts almost like a GPS, so that

the sperm have a good indicator of which fallopian tube to go to.

There, the egg and the sperm are almost within reach of each other.

The female reproductive tract releases a cocktail of protein and calcium, which gives the sperm

the strength to beat their tails harder and swim faster than they did before.

This fluid also helps the sperm weather away this little cap.

And once it's gone, they secrete enzymes that help it dig through the two layers of

the egg's protective outer shell.

I feel like every text we looked at had the word penetrate.

We think of the word penetrate as neutral, but think about when we use that language

of penetrate.

We talk about forces penetrating army lines and we think about war. Penetrate is this

language of like an assault, of doing harm.

Penetrate is not a friendly, like, welcome in.

The egg doesn't just wait around to see which sperm will break through:

It uses chemicals to select the best sperm, the one that will produce the healthiest offspring.

And its work doesn't just stop there.

Once the egg and the sperm come together, the selected sperm deposits its genetic information.

The egg essentially self destructs all of its other sperm receptors to make sure no

other candidates can get it.

And it combines with the egg to start forming what will soon be an embryo.

And that is how fertilization really happens.

This idea of who decides and who the experts are in the field...in science it's been white

men for a very long time.

Like the first person who ever saw sperm under a microscope scope was a man. And he had assumptions

about what it was.

If the assumption is that the sperm is the most important part of the whole puzzle, it's

not like that's going to necessarily be challenged if all the people at the table are men.

80% of the textbooks Lisa and Nadia analyzed had descriptions that were at least somewhat

gender-biased.

It can be done. It can be explained in a fact based, unbiased way. But it isn't always.

What we're talking about is not just changing language in a textbook.

What we're also talking about is systems that are in place and have been in place for a

very long time.