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Lucy Writes

Having a child with one kidney aka unilateral renal agenesis

By June 25, 2024No Comments

My son is five and a half and perfectly healthy and these days I feel completely calm about the fact he has a condition called unilateral renal agenesis – which means he has one kidney. Sounds scary doesn’t it? I’ll take you back a bit to when I first found out about my unborn baby’s one kidney.

It was September 2018 and I headed off to Margate Hospital in Kent for my 20-week screening scan. Dan was away so I went on my own. I mean I’d done scans many times before and so I breezed in thinking that I’d breeze back out again. I got myself comfy on the scanning bed, the lights were turned down low and the cold blue gel was smoothed over the lower part of my baby bump by the sonographer. As the handheld probe was being pushed into where my womb was, a series of measurements were being taken – click, click, click – something I was very used to after having had two children already.

Around the time of my 20-week scan

The clicking stopped and the gliding continued across my abdomen. I had a sense that something wasn’t… normal. The sonographer called for a colleague and together they scanned and looked at the monitor whilst I was laying on the bed. After what felt like forrrrrever, this line was delivered to me: “we think your baby has only got one kidney”. I have no idea what I said afterwards. All I remember was the news was dellivered in a matter-of-fact way, there was no beating around the bush, or any caring language. In addition to the one kidney new blow, I was told I had polyhydramnios – which means too much amniotic fluid.

OK. Ohhhhhkay. OK. I was OK.

I was not OK.

The one kidney news didn’t sink in at the time. At the appointment I was told it wasn’t 100% that my unborn child had this condition, and it might be that the kidney they couldn’t locate on the scan could be hiding, smaller, or much lower in the baby’s groin area. I would have to come back for additional scans when the baby was bigger at around 28-weeks pregnant. At 20-weeks, the baby is around the size of a banana and so they are scanning organs that are very very tiny, which is why they need further investigations as the foetus grows.

The news that I had too much fluid seemed easier to take I think because my bump was tight and I was quite uncomfortable. I was booked in for a gestational diabetes test to see if that was part of the cause, which happened a few weeks later.

The unilateral renal agenesis news was harder to take because it was all a bit unknown, I had no ‘symptoms’ and so it all felt very weird that my baby might have a life condition. I went home after the scan and cried. I cried a lot. I immediately pulled out of a work speaking engagement that involved a flight and busied myself with the girls (they were 6 and 8 at the time) and cooked, cleaned and tried really hard not to google anything. I was semi-successful in not reading about things online, but did frighten myself a couple of times as I stumbled across content from some of the kidney charities. If you are reading this and have just found out your unborn child has one kidney, don’t google don’t google don’t google anything other than NHS UK (if you are in the UK of course) or if you are elsewhere, consult trusted medical websites only.

Weeks later it was confirmed (via scan) that my baby boy did in fact have just one kidney and I was booked in for regular scans (more than normal) due to a) my age b) my boy having one kidney. Nearing the end of the pregnancy I was given a care-pack and reassured that I could have a normal birth (whatever that means) and was told my newborn would have to be on antibiotics for the first six months of his life. The reason for this is to safeguard against any urine/kidney infections. The dosage was tiny and given to him orally via a little plastic syringe every day. I honestly can’t remember if this was once or twice a day, those newborn days are hazy at best! (recovering from birth, feeding, nappies, other kids, school runs, no sleep etc).

My son was born 8-days after his ‘due date’ and he was a healthy 7lbs 7oz (3.5kg). He breastfed beautifully and gained weight as expected. He hit all his growth and weight milestones and started walking at 10-months!

Lucy and son, aged 5

This is a list of the checks he has had and the ones he continues to have:

  • Urine reflux test (around 5-months) – to check that some of the urine produced doesn’t go the wrong way (back to the kidney). This was done at the hospital and happened in the x-ray room. A liquid with a special dye was put into his bladder via catheter and when he had a wee an x-ray was taken at that very second to capture where the liquid was going.
  • CT scan on his kidney (6-months) – this was to see the size and shape of his left kidney.
  • NHS consultant appointment (just after 6-months) – this was to discuss results of the above – all normal.
  • Annual checks with kidney specialist (nephrologist) – every year my son has height, weight and urine samples checked and on the last check he had an ultrasound scan on his left kidney – which he loved! This was done at our local NHS hospital.

A few extra things that I think might be useful:

  • I treat him as a totally normal child.
  • All care-setting he has been to have known about his condition.
  • I try to make sure he drinks water, milk or weak squash only.
  • We make no dietary adjustments, apart from I am a little cautious with salty foods.
  • I read that he should not play any ‘contact sports’ but his consultant said he is fine to do anything! That said, I will not let him box or play rugby (phew!).
  • As a family we talk to him regularly about his one kidney and normalise it always.
  • There is no known reason for a child being born with one kidney.
  • Many people of my generation who were not scanned at birth (1976 baby here) could be walking around with one kidney and not know. I have been scanned now but my husband hasn’t – so for all we know he could have one, too!
  • Author Bill Bryson found out he had one kidney at 60 when he went for an MRI for a hernia.
  • Many people donate one of their kidneys and live normal lives.
  • The single kidney grows larger to compensate for the other one not being there.
  • This condition is not linked to be an older parent.
  • If you have recently had a scan and been told your baby has one kidney, please try not to panic. Don’t time-travel to a place where you imagine all the worst case scenarios – it might be a shock, but your unborn baby needs you to be strong and try to make sure you only live moment-to-moment and ask all the questions – it is all you can do.

And that’s it!

I receive quite a few emails and DMs about this and am always happy to talk about it, please email me: 

Sending love,

Lucy x



Lucy Baker

Lucy Baker

Lincolnshire-based Lucy Baker is the founder of Geriatric Mum blog and mum to three children who are age 12, 10 and 3. Lucy had her last baby at 43-years-old - which is why this blog was born.

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