– English Lyrics

Lyrics & Translation

[English]

Pregnancy is a hardcore sci-fi epic of war,  peace and compromise. Babies are basically  

very cute tumors that grow a completely new  organ inside a different human. Their mom’s  

body graciously allows this, while the new  life saps her resources and challenges her  

immune system to its limits for months.  Biology is brutal and beautiful and metal.

Let us zoom in and observe this brutal  struggle for survival – that in the best  

case ends in one of the most  magical things: A new life.

Our story begins with an army of  tens of millions of sperm cells  

that immediately face death. They  are on a tight timer before they  

run out of energy and die. But this is  the least of their problems right now.  

Like all bodily openings, the female reproductive  tract is a fortress defending against invaders.

The future mom’s body has set up deadly  barriers and puts the sperm through a  

brutal process that kills almost all of them and  ideally selects the strongest and fittest one.

The first deadly obstacle is a highly acidic  environment guarded by hundreds of thousands  

of guard cells. The acidity kills millions,  especially of the weaker sperm within the first  

half hour, although they have a bit of protection:  Seminal fluid is alkaline and so it makes this  

first obstacle a little less deadly. The survivors  reach the next obstacle, a treacherous maze full  

of protein nets where millions more find  a brutal end getting stuck and lost.

Now if a woman is in the part of  her menstrual cycle where she is  

ovulating , her body helps the sperm out a  bit, by releasing chemicals that guide the  

way and by being a bit less hostile. Luckily  for our brave sperm this is the case today.

Only a couple hundred - less than 0.0001% of  the original sperm - pass through into the  

uterine cavity, where two tunnels branch out.  Here mucus helps transport the stronger sperm  

to move on, while weeding out the weaker  ones. The mom’s immune cells pick off and  

devour every cell that trails behind or  takes the wrong turn. And then finally,  

maybe just a few dozen sperm reach  their goal, the mighty, giant egg.

10,000 times bigger than them, it is  an industrial scale monster loaded with  

nutrients and nearly 100,000 mitochondria,  the powerhouse of the cell – 50 times more  

than an average cell. But the egg is  not easily conquered – the survivors  

get closer and try to get in until the egg  decides to accept a single one of them.

The genes of two individuals merge. The  egg stops being part of its mother – it  

is something else now. A new being  with its own agenda. Not a human yet,  

but the potential to become one. Like a  thought that is not yet a word. But its  

mom’s body hasn’t decided yet if she wants to  say it out loud. It will have to fight for that.

For a few days it rapidly divides and grows to a  couple of hundred cells, while traveling down to  

the uterus, the part of the female reproductive  system where it will try to make its new home.  

Here it begins to divide into two specialised  teams of cells - one will eventually become the  

baby. The other cells are trophoblasts and  their job is to turn into a temporary organ  

inside the mother: the placenta, that will  make pregnancy possible and eventually die.

This means that when you were an embryo  there was this whole other part of you,  

not like a twin, even closer, maybe like a  guardian angel clone. These cells never had  

the chance to become a human, their only  purpose in life was to make you exist.

In any case, the following days are the most  dangerous for the potential new life. Like a  

tennis ball rolling through syrup the young  embryo moves along the uterus and tries to  

take a hold. An intense chemical dialog between  two living things begins, the embryo releases  

dozens of chemicals that announce its presence  and asks the guard cells of the uterine wall  

to allow it to please, please, please attach  itself so it can survive. The uterus responds  

with dozens of hormones and immune signals  itself. If it is satisfied with the quality  

of the chemical conversation its cells allow it.  If it doesn’t the embryo will be lost and die.

This is where we begin to see that the interests  of both living beings no longer completely align  

anymore. Pregnancy is a huge energy investment  so the mother’s body will eject the embryo if it  

doesn’t see it as viable. The embryo on the other  hand faces a life and death situation and tries  

to stay alive at any price. So it’s not asking  politely but deploying thousands of infiltration  

units: Bubbles filled with genetic material, kind  of like a human virus! They sort of invade the  

uterine cells and try to brainwash them, so they  help it attach itself, rather than rejecting it.

During this time one of the weirdest  features of pregnancy occurs: the  

uterus provides uterine milk, not real milk  but a clear fluid filled with nutrients and  

hormones that the young embryo sucks up hungrily  to gain additional energy until it gets inside.

If the embryo is allowed in, the implantation  was successful, the first critical hurdle. The  

next step is to reach the blood vessels  of its mother, the only way to survive if  

it doesn't want to starve. The trophoblasts  begin to clone themselves on a massive scale  

and turn into different specialists. One of  them turns into a violent invader that starts  

drilling into the uterine tissue like a  tiny parasitic octopus with many arms,  

spreading and growing. This is a brutal  process, ordering loads of it’s mom’s uterus  

cells to destroy themselves, killing others  directly or even devouring some cells whole.

While this sounds brutal, and it is, this process  is highly regulated and doesn’t hurt the mom. It  

is another test. The mom’s body monitors carefully  how the embryo is doing – is it growing quickly  

or if it is more chill. If an embryo has genetic  damage or chromosomal abnormalities it will spend  

way more energy on repairing itself and maybe  grow more erratically. This makes it metabolically  

noisy, releasing loads of chemicals the mom’s  immune cells pick up. Which provokes them and  

makes it more likely that they will destroy it.  On the other hand, if the embryo is weak it is  

metabolically too quiet and the mom will stop  talking to it – which also ends the pregnancy.

This embryo is just right, so the mom’s cells  release a flood of different chemicals to help  

it out, support it growing and most importantly,  they activate her immune system. Usually this  

would be very bad – the immune system kills  everything that is not part of the mom’s body,  

and this embryo is clearly not part of her. But  the immune cells of the uterus surround the embryo  

and start helping it, guiding the trophoblast  to grow further. They create a physical and  

chemical safe zone that tells dangerous  immune cells like T Cells to stay away.

The embryo has its own motives and doesn't want to  rely on its mothers goodwill alone – so defensive  

trophoblasts send out signals that kill her  immune cells if they get too close and could  

start attacking it. Hundreds of cells go even  further and leave the embryo behind. They spread  

all across the mom’s body, entering organs, even  the brain. We don’t know what all of these cells  

are doing but we think that they are probably  telling her immune system that the embryo is not  

to be attacked. That it should be left alone or  even protected. These cells may stay inside the  

mother for years or even decades. It is likely  that parts of you are still in your mother.

Around 8 weeks after the egg was fertilized,  

the transition from the embryo to  fetus begins – the size of an olive,  

its organs begin to form and it turns from a blob  into something vaguely human-like. Is there a  

clear point where a clump of cells becomes a  human? Not really – it is a fluid transition  

and every society and person - be it morally  or legally - marks this moment differently.

Meanwhile construction trophoblasts  are busy building a spongy fingerlike  

structure that expands further into  the uterus, a completely new organ:  

The placenta – an organ that you once grew inside  your mother, that was ejected after your birth  

and died a silent death while everybody  was busy welcoming you into the world.

In our story the placenta is now the new  home of the fetus. An enormous fortress,  

protecting it from microbes that could infect and  kill it in its still pretty fragile state. It even  

has its own mini immune system, placental  immune cells that gobble up anything that  

poses a threat. Other placental cells creep  along the inside of the mom's blood vessels,  

stretching them and connecting the fetus  through the umbilical cord on the other  

side. With the blood flow secured, it’s  time to load it with as much food as  

possible. The placenta releases hormones  that funnel glucose directly to the fetus,  

stealing energy from its mom. If the fetus goes  too far and asks too much, this can sometimes  

lead to gestational diabetes for the mom during  the pregnancy, starving her body of energy.

The mothers body is trying to support the  new life, but not at the cost of her own  

survival. In a sense the mothers genes inside  the fetus still have a stronger allegiance to  

her than to the new being – but it’s fathers  genes don’t. They want the fetus to survive  

at all costs. So while there is a sort of  fragile peace between both parties, it is  

just that – their interests are not perfectly  aligned and both sides have to deal with that.

In the next few months the fetus will  increase its weight over a billion times,  

which demands a staggering amount of energy  and cooperation. They still need to work  

together to get out of this alive. But if the  fetus gets to this point in the pregnancy,  

chances are pretty high that it will  become a baby like you once were,  

a proper human, like you are today.  A being with immense potential.

If you are alive today then you went through  an amazingly brutal selection process. From a  

little pack of genes traveling through  an incredibly deadly obstacle course,  

fighting for your survival, with desperate  words spoken through chemicals and sneaky  

actions trying to outsmart the system,  fighting to be alive in this world.

But this is only one side of the story –  you were also chosen – by hormones that  

led you to the right place, by the egg  allowing you to merge into one. By your  

mom’s body that liked how you spoke to her,  by her cells that protected and cared for  

you. Nourished by an incredible amount  of energy that your mother gifted you.

Our biology is a brutal, unforgiving, but  necessary part of the greatest wonder there is:  

The creation of new life, of you, of all of us.

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Key Vocabulary

Vocabulary	Meanings
pregnancy /ˈprɛɡnənsi/ B1	noun - the state or condition of having a developing embryo or fetus inside the womb
sperm /spɜːrm/ B2	noun - a mature male reproductive cell
egg /ɛɡ/ A1	noun - the female reproductive cell
embryo /ˈɛmbriəʊ/ C1	noun - an unborn or unhatched offspring in the early stages of development
fetus /ˈfiːtəs/ C2	noun - an unborn human baby more than eight weeks after conception
placenta /pləˈsɛntə/ C2	noun - the organ that connects the developing fetus to the uterine wall
cells /sɛlz/ B1	noun - the basic structural and functional units of living organisms
body /ˈbɒdi/ A1	noun - the physical structure of a person or animal
life /laɪf/ A1	noun - the existence of an individual human being or animal
organ /ˈɔːɡən/ A2	noun - a part of an organism that is typically self-contained and has a specific vital function
survival /sərˈvaɪvəl/ B1	noun - the state or fact of continuing to live or exist
grow /ɡroʊ/ A1	verb - to increase in size or develop
invade /ɪnˈveɪd/ B2	verb - to enter a place in large numbers, often aggressively
attach /əˈtætʃ/ B1	verb - to join or fasten something to something else
development /dɪˈvɛləpmənt/ A2	noun - the process of growing or becoming more advanced
human /ˈhjuːmən/ A2	adjective - relating to or characteristic of people noun - a human being
immune /ɪˈmjuːn/ B2	adjective - relating to immunity or the immune system