My daughter is here. Curled up in a hedgehog ball, but softer than anything in the universe. She is born with a quiff of thick black hair and an expression that says she’s been here before. A knowing, testing look. She is early, and small. I begin assessing my baby as if she’s one of my intensive-care patients. I check her reflexes, pupil reaction, respiratory rate and capillary refill time. Mary, the maternity support worker, watches me and laughs. “Nurses and doctors – always the worst patients.”

I try not to think of all the babies, children and adults I’ve cared for who were seriously ill, but I can’t stop. I realise that when my daughter hurts, I will hurt more. And she is not hurting. She is fine. But something in me shifts. I think of all the faces of the mothers and fathers and aunts and uncles and grandparents of my patients through all my years of paediatric nursing. I try to imagine their primal pain. How could I not have appreciated the extent of it? In the most desperate of unimaginable horrors, in the face of disability, or serious illness, or pain, or loss, how do patients’ families stand upright? How do they find the courage to care?

I pull my daughter closer and kiss her. She smells of honeysuckle and salt, and Plasticine when the packet is first opened, and warm bread, and blood. She is perfect. How could I imagine a love like this?

***

“Crash call for the neonatal, adult and obstetric teams. I repeat: crash call for the neonatal, adult and obstetric teams. Accident and Emergency. Ground floor, Cavell Wing.”

There’s only one explanation for why you would need three crash teams at once: a heavily pregnant woman is in trouble. The adult team is to resuscitate her; the obstetrics team is to get the baby out (within five minutes, if either of them is to have any chance of survival); and the neonatal team is to try to resuscitate the newborn. Like all the other resuscitation nurses, I am on all the crash teams – adult, paediatric, neonatal, obstetric and trauma – but this crash call will also bring specialist doctors: an obstetrician, a neonatologist, an anaesthetist.

Suzanne is wearing a necklace that reads Mama-To-Be. A leopard-print headscarf is holding her ombre hair back from her face. The rest of her is blood and gore and flesh and insides.

There are so many people that it’s hard to know where to start, but the person in charge is a nurse with a military background: Amanda. She is one of the best nurses I have ever worked with, a reservist who has worked in field hospitals in Iraq and Afghanistan. She is always calm, efficient and friendly. “Just because it’s an emergency doesn’t mean you can’t find out the names of the team, and be nice. In fact, it’s even more important in an emergency.”

Amanda glances over, so that she knows I’m here whenever she needs. I start tidying up, working on the periphery.

“RTA [road traffic accident].” A nurse hands over the patient. “No sign of the bleeding stopping.” Two nurses on either side of Suzanne hold up pouches of blood that they are squeezing into her, but nowhere near as fast as the blood is squeezing out.

I do not see how Suzanne or her baby can survive. I focus on the drops of sweat on Amanda’s face, her eyes wildly searching for control, a plan – a way to save this woman and her baby. Or at least one of them. I try to imagine the things she has seen and experienced in her military role. I can’t think of anyone better to lead such a horrific emergency.

“She needs to be in theatre as soon as we have this baby out. Like yesterday!” A doctor is on the phone, asking for flying-squad bloods. I watch the defibrillator. Amanda asks a member of the team to put the pads on Suzanne’s chest in advance of a surely imminent cardiac arrest. The obstetrician pulls the baby from her, lifts it out, wipes off the goo vigorously and places it on the Resuscitaire, for another doctor waiting there with a miniature bag-valve-mask and a stethoscope, straight to the baby’s chest. The obstetrician leaves Suzanne split open: it’s impossible to see where the blood is coming from. Large gauze squares do nothing to mop up anything. Anyone can see it’s a devastating amount to lose.

There are too many people around Suzanne’s trolley. Despite the lack of room, everyone moves at speed without bumping into one another, each person perfectly choreographed by Amanda.

Suzanne’s husband, Simon, is standing outside the room. I go out and stand next to him. His bottom lip is bleeding a little, where he’s bitten it. I tell him I’ll wait with him while they are helping her. But he doesn’t hear me, not really.

“She’s ordered a Bugaboo pushchair and is spending her pregnancy ordering everything possible from the Boden catalogue,” he says. “I never imagined we’d end up as this couple.” He laughs a too-thin laugh. “We met in a squat.” He makes a loud noise as he exhales, as if he has no control of his breath.

His face is creased with pain. “After 10 failed IVF attempts and two miscarriages, we finally felt as if this one would stick around.” He looks at me, unblinking. “She’ll lose the baby, won’t she? We’ll lose the baby. It’s too early. She was on the phone to me from the car. She was hands-free but still, she’d have been distracted.” He sobs. Covers his mouth with his hand.

I don’t say anything. I don’t know yet what he’s been told, but it’s clear that I’m not the right person, and this is not the right time to give significant bad news. I’m terrified that if I open my mouth, the truth will fall out. The terrible truth is that they will probably both die. Not all babies live. Not all mothers live.

We stand in silence for a while, before finally I overcome the urge to cry or say nothing at all. “Is there anyone I can call for you?”

He shakes his head. Nods at the door. “She’s my everyone.”

I nod. “I’ll pop back in and see how things are going.”

As I go through the door again, I have to swallow down sick. I look at the scene in front of me. The staff are covered in blood, as is the floor.

I focus on the baby on the Resuscitaire, grey and small, and stretched out rather than curled over, as is normal. But the neonatologist looks up at the team: he gives us the thumbs up. This baby lives. I exhale.

I rush out to tell Simon.

“They are working on Suzanne and she’s still critical. Everyone is doing all they can.” I pause. I don’t want him to underestimate how sick she is. But I can see that he needs something to hold on to. “Your baby is alive.”

He looks at me in a kind of trance. “I’m a dad?” he asks.

He is clearly so full of love. He doesn’t ask whether the baby is a boy or a girl, and nor do I. When things go this wrong, nobody gives a shit.

Suzanne is somehow stable. She is placed in the high-dependency ward and her baby is on special care.

I bump into Simon in the corridor two days later, rushing between the two. He is carrying a soft toy hippo. He looks like the happiest man in the world.

“Suzanne slept with the hippo against her skin. The midwife said our daughter can smell her, and it’s the closest Suzanne will get to skin-to-skin for now.”

“Daughter?” I am smiling.

He’s crying. Happy tears. “I’m a wreck,” he says. “She’s so beautiful. Like her mum.” He holds the hippo as if it’s his baby. “I’ve turned into one of those baby bores who gets excited every time she moves.” He laughs. Then he bursts into huge, fat tears, a mixture of pain, trauma and relief. He tells me about Suzanne: how she didn’t wake up for a long time, and it was the scariest moment of his life.

“We’re thinking of calling her Amanda, after the doctor who saved her mum’s life.”

I smile. “Amanda is a nurse.”

***

The adoption process is hard, as it must be. In the early stages, we were asked to list the things that led us to adopt. Miscarriage, I write. Hyperemesis gravidarum, extreme morning sickness. Advised by GP not to get pregnant again. Wanting three-year-old daughter to have a sibling as close to her as my brother is to me. Hoping to do some good? The social worker tells us that children who need to be adopted have extra special needs and there are many uncertainties, so many unknowns. But nursing has allowed me to understand that all parenting is full of uncertainties and unknowns. I have seen close up the most extreme suffering and the most extreme love.

The day I bring my son home, it is my birthday. When my social worker asked if I’d like to change days, I laughed out loud. I am desperate to hold him. One night I dream about an umbilical cord that stretches the length of the country and awake with pains in my abdomen.

But we are warned about a honeymoon period and things do get very hard, very quickly. He begins to get frightened. He almost seems to see things that aren’t there and hear loud noises in his head. After the initial few days, my son spends the first six months clinging to me, his fingers digging into my flesh so hard that he once draws blood.

My mum visits. “What if I’m wrong for him?” I whisper, looking at my son.

“Do you love him?” she asks.

“So much,” I say. I lean my head on her shoulder. “I can’t even describe it.”

She kisses the top of my head as if I am a child. “Then it will all fall into place. I promise.”

The following week I take my daughter to her swimming lesson and the noise of the leisure centre freaks my son out so much that he bites me, hard. I yelp. A woman I recognise from the local cafe shouts across the swimming pool viewing area: “Is that the adopted one?” My son turns and listens, and I absolutely know in my bones that he understands what she has said. His face fills with tears. He does not belong. My son and I look at each other. Something shifts. “Is that the adopted one?” she shouts over again. “I see you are struggling.”

And I look at my son, this virtual stranger. And he looks at me, this virtual stranger. I stand up and hold him to my body. I walk to the exit, past her, and she touches him. I feel him flinch. I flinch.

I hold him closer still, with my arm around his head, away from her. And I feel his fear through my skin. I lift my head high and stare at her.

“Oh, fuck off, Janet,” I say. And we go. And he relaxes. For the first time he puts his head down gently on my shoulder. He rests it so gently I can barely breathe. I kiss his head. And he lets me. In that single moment, whatever happens, he somehow knows he is OK. We both are. I am reminded so clearly of the day my daughter was born and the enormity of love that I felt. How could I feel a love like that again? Yet here it is. We are so lucky.

***

“Michael is a 23-weeker in bed six, bay two. His dad’s in prison and his mum is in a facility needing round-the-clock care following a traumatic brain injury. Michael has had a grade-four intraventricular haemorrhage overnight and has been unstable on dopamine, and his gases are impressive. We need to put him back on the oscillator this morning. We’ve been trying to organise for his dad, Danny, to get day-release to visit.” She pauses. “He kicked the pregnant mum in the stomach, then threw her down the stairs. She landed on concrete.”

Like the other nurses and student nurses sitting in the staffroom for handover, I shake my head a fraction, but carry on scribbling down the vital information. The nurse in charge pauses a beat, then carries on. She’s seen it all before. “Christie, can you look after him, please? If they agree to the visit, the dad will be accompanied by a prison officer, so we’ll need to make some room around the bed space and be conscious of the other parents.”

I nod, but my knees shake. The oscillator machine, which delivers ventilation to the sickest of all babies, is a scary thing, as is caring for a premature baby with a severe bleed in his brain. But it is not those things that worry me.

Kicked in the stomach and thrown down the stairs.

What kind of monster does that?

I pray to any god I can think of that they won’t let the man out to see his son and that I can simply concentrate on caring for Michael. He is hooked up to every machine imaginable – all big, chugging technology with him in the middle: like a full stop in the centre of a chemistry textbook. He has all the trappings of prematurity: lungs that do not yet produce enough surfactant, a gut that does not yet absorb food properly, poor reflexes, a lack of temperature control. He has suffered the worst kind of bleed to his brain. He also has retinopathy of prematurity, the eye condition that caused Stevie Wonder’s blindness. But these conditions don’t paint the picture of him. When I first meet Michael, I notice the downy hair that I recognise from caring for teenagers suffering from anorexia. His skin is almost entirely see-through, and his entire foot is the size of my thumbnail. He has a permanent frown, which makes him look like a grumpy old man, and he smells of yoghurt.

“He’s the size of half a bag of sugar, but he is oh-so-mighty and has dodged death so many times that we call him ‘the mouse with nine lives’.” One of the nurses, Grainne, is giving a handover at the bedside. She has written Mighty Mouse on his whiteboard. “We shouldn’t have favourites,” she says, as if she’s talking about her own children, “but he’s mine.”

She tells me his history in his short three days of life. Born addicted to crack cocaine and heroin, even in his tiny state he shows signs of foetal alcohol syndrome: characteristic facial features and a small head circumference known as microcephaly. Some children are born with the odds stacked so high against them, it’s impossible to comprehend any meaningful recovery, yet nursing has taught me that it is always a possibility. There is always hope.

Michael’s “Mighty Mouse” nickname hints that he might have the will to survive. “I’ve been singing to him all night,” Grainne says. “I think my voice made him frown.” She laughs. But it’s these things that nurses do, which supposedly make no sense, that make the most sense to me.

Danny is handcuffed to a prison officer and is next to Michael’s incubator when I return from breakfast at 4pm, my first break of the day. Being non-judgmental towards abusers is difficult and I’ve learned to hate and judge while keeping a poker face. I smile at him and explain the tubes and wires. “Michael’s had a very rough few days.” I tell Danny about the cardiac arrests, the bleed in his brain, the fight in him.

Danny laughs at the Mighty Mouse written on the side of Michael’s chart, but he rubs it off and writes Mike Tyson instead. “Little fighter, like me,” he says.

“I was born early, too.” Danny is stroking Michael’s head in the softest way possible. “A small bag of sugar.” He looks up at me. “Six foot two now.”

“It’s a strange phenomenon that ex-premmies often end up so tall,” I say. We both look at Michael. He is extremely unlikely to survive.

I encourage Danny to touch Michael, to talk to him and sing to him. He cracks up laughing at the suggestion of singing, but puts his hand gently underneath Michael’s miniature body and lifts him slightly as I pull the corner of his special sheet to make sure there are no creases. There is a moment, between the two of them. Michael is curled into the palm of his dad’s hand. Danny’s eyes change. It’s one of those extreme moments of love that shock us out of who we are and remind us of who we could be.

I take a photo with one of the instant cameras that are always kept in the neonatal intensive care unit, for when a picture urgently needs to be taken. Usually when a baby is close to dying, I take two photos. I take one of Danny’s face, and then a closeup of Michael, curled up in Danny’s hand.

It’s a short visit and when it’s time to go, I give Danny the photos. He looks at the one of Michael and he is crying. “I’ll treasure this, nurse.”

And I see that he will. It does not allow me to feel pity for him, but he is no longer a monster to me. Just a weak man.

“Wait,” I tell him. I disappear and come back with the camera. “Can you hold him carefully again.” Danny picks Michael up and I get the photo – almost exactly the same as the first one. Michael’s heart rate, which was much too high, falls at the touch of Danny’s hand. His father leans towards him and sings, off-key, a few lines of Danny Boy.

I wonder if a man ever sang that song to Danny. If that’s how he got his name. And what kind of man he was.

Like teachers, nurses can’t influence who a person becomes as much as their parents can. We cannot change the cards they are dealt. Even so, after Danny leaves, I wipe the words Mike Tyson from Michael’s whiteboard. I stick the extra photo to the top of his incubator and write at the top: Important. Please Keep, along with the date and Danny’s name. I write on the whiteboard:

Michael, son of Danny and Hannah.

***

Spring 2020. I am walking across Westminster bridge. Behind me, the Houses of Parliament are empty. In front of me, the hospital is full of people seriously ill and dying from Covid-19. The bridge is empty of cars and people, even rough sleepers. I wonder where they have gone.

I walk slowly at first. I am so worried for my mum, on her own. And for my nan, shielding and in her 90s. I stop for a moment and text my children. They have grown up overnight. I am a single parent and my 15-year-old daughter, instead of going out to parties and falling in love for the first time, is offering to stay on top of her home schooling and keeping an eye on her younger brother, so I can work long days in nursing. She is planning to cook, so there is a meal waiting when I get home. I tell her she doesn’t need to do that because her adult sister – her dad’s eldest – has offered to stay to help, but she is already writing a menu. Pesto pasta features heavily.

“I feel bad about not focusing on you. We ought to be together during this time,” I say at home.

“Will you help people?” my daughter asks. I nod and tell them I’m rusty but that, with training and support, I’ll help the nurses, and the patients and their families. I’m planning to help for the first peak, though I have no idea how long that will last. “Do it,” she says.

I stand back and look at her grinning, remembering her newly born, curled up in a hedgehog ball. How astonishing she turned out to be. I may not be feeling brave, but my children are. It is always from them that I find the courage to care. My son nods and puts on his determined expression. “You must.”

Back on the bridge, I am almost running now. I think of the nurses I have worked with, these expert and compassionate people, and what they have taught me. I get to stand next to them, for a while at least. This pull of my feet and my heart and my head is older and deeper than I can describe in language. Perhaps, for me at least, this is a calling.

I slow down at the entrance to the hospital and walk in, catching my breath. My colleague, Sandra, is waiting for me, wearing scrubs and carrying a spare pair for me. We haven’t seen each other for a few years, but there is no time for small talk. She hands the scrubs over and nods. “Welcome home.”

• Some names and details have been changed. The Courage To Care by Christie Watson is published by Chatto & Windus on 17 september at £16.99. To order a copy for £14.78, go to guardianbookshop.com. Comments on this piece are premoderated to ensure the discussion remains on the topics raised by the article. Please be aware that there may be a short delay in comments appearing on the site.