What is protein with urine in pregnancy?

A pregnant woman is holding a container for a sample, collecting urine.

by Adejumoke Ilori |
Published on

Protein in urine, or proteinuria, is a common and significant finding during pregnancy. This condition can range from mild to severe and may indicate various underlying health issues. Typically, small amounts of protein in the urine are normal, but excessive levels can signal potential complications.

During pregnancy, the presence of proteinuria often warrants careful monitoring and further investigation, as it can be a marker for conditions such as preeclampsia, a serious pregnancy-related disorder characterized by high blood pressure and damage to organs, most often the liver and kidneys.

Understanding the implications of proteinuria in pregnancy is crucial for ensuring maternal and fetal health, as it helps in the timely diagnosis and management of potential complications.

According to midwife Lesley Gilchrist, founder and clinical director at My Expert Midwife: "Urine plays a significant role throughout your pregnancy from first peeing on an ovulation stick when tracking your fertility, or on a pregnancy test stick, through to having urine testing at every antenatal contact and measuring your first post-birth pee volume. Midwives and obstetricians are urine obsessed, or so it appears, but why? Quite simply, your urine can tell us so much about your wellbeing and general health in pregnancy."

Read on as we find out more about protein in your urine during pregnancy.

How is urine produced?

Urine is produced in the kidneys which in effect clean the bloodstream up, so during pregnancy they work even harder than they do in a non-pregnant person clearing waste from mum and the pregnancy. For some women this might mean they feel the strain a little, and any burning or stinging when urinating needs reporting to a midwife or GP.

Who is my urine assessed by in pregnancy?

Your urine will be assessed by a midwife, doctor, or healthcare assistant by dipping a sample with a special stick which can detect several different substances such as glucose, infection markers, and protein. "You should be offered a urine test at every antenatal appointment as well as other routine screening tests such as blood pressure," says Lesley.

Woman holding toilet roll
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What is my midwife looking for in my urine?

Protein is the main substance that healthcare staff will be looking for in your urine. Protein can indicate the presence of infection, or a more serious pregnancy-related condition called pre-eclampsia. If it is found in your urine your sample might be sent to a lab for further investigations to find out what microbes it grows, if any, and what antibiotics those particular microbes are sensitive to. Protein alone could be the result of sample contamination from a heavy vaginal discharge, so midwives prefer you to obtain a mid-stream urine (MSU) sample to avoid any contamination from an otherwise healthy discharge.

To obtain a MSU pee a small amount into the toilet, catch the middle of the stream, allow the rest to go back into the toilet. Ask your midwife for a white top urine bottle before you leave each appointment, so you have one for next time. Lesley suggests, "You might find it easier to use a clean pot or jug to catch the sample and then decant into the bottle, especially in later stages of pregnancy when your growing baby bump might make this task slightly more difficult."

What if I have protein in my urine?

If you have protein in your urine before 20 weeks of pregnancyit is likely to be chronic proteinuria due to a pre-existing condition affecting the kidneys, or other health problems that might not even be related to your pregnancy, like heart disease.

If you have protein in your urine and you also have raised Blood Pressure (BP), then it is likely that you will be diagnosed with pre-eclampsia. Pre-eclampsia is a condition that can affect any pregnancy, usually later in pregnancy, but can present as early as 20 weeks, and even earlier in some rare circumstances. "For some women it can start during labour or even in the postnatal period up to six weeks following the birth of a baby," Lesley adds.

What is pre-eclampsia?

Pre-eclampsia is a serious condition determined in the very early stages of pregnancy when the placenta has formed and is embedding into that wall of the uterus. Long story short, the vessels that transport blood from mum to placenta to baby and back don’t form correctly, resulting in uterine arterial restriction, constriction of the blood vessels, and a reduction in transfer of essential nutrients and oxygen. This does three things:

• It raises mum’s BP

• The raised BP causes protein to leak out of the blood through the walls of the vessels into the extra-cellular fluid, which is then excreted in urine

• Baby can be compromised and growth restricted by lack of nutrients.

If pre-eclampsia is left untreated it can result in eclampsia, a severe complication as a result of pre-eclampsia. Women with eclampsia present with seizures which are a medical emergency and require immediate treatment. Evidence shows that approximately 10 per cent of pregnancies worldwide will be affected by hypertensive diseases of pregnancy including pre-eclampsia, and of those approximately 3 per cent (0.3 per cent of all pregnancies) will go on to develop eclampsia. Early diagnosis and treatment of pre-eclampsia is vital to reducing the risk of developing eclampsia.

Symptoms of pre-eclampsia

As well as proteinuria (presence of protein in urine) and raised BP, there are a number of other red flag symptoms that could indicate pre-eclampsia. Pre-eclampsia can develop very quickly, and it is important that if you experience any of the symptoms below you should alert your healthcare team so they can investigate further:"

• Nausea/vomiting

• Persistent headache that does not settle with paracetamol

• Visual disturbances – spots, blurred vision, or flashing lights

• Epigastric pain – persistent pain underneath the ribs

• Oedema – swelling mainly to hands, face, and feet but can be generalised

• Reduced fetal movements – noticing baby moving less than their normal pattern

Who is at risk of developing pre-eclampsia?

Although pre-eclampsia can affect any pregnancy, we know that some women are at increased risk of developing it including:

• Primiparous (first baby)

• First baby with a new partner

• First degree female relative (sister or mother) diagnosed with pre-eclampsia

• Existing hypertension (raised BP)

• Pre-existing diabetes or kidney disease

• Pre-eclampsia in a previous pregnancy

• Aged 40+ years

• Body Mass Index (BMI) of 35+

• Expecting multiples (twins, triplets or more)

• 10+ years since last baby

If you are identified as being at increased risk of pre-eclampsia during your booking appointment, you will be offered a prescription of aspirin from 12 weeks of pregnancy until you give birth. You will also be advised to follow a programme of regular low-impact exercise and ensure you have a healthy and varied diet.

I have been diagnosed with pre-eclampsia. What next?

You might be prescribed oral anti-hypertensive medication to reduce your BP such as labetalol, nifedipine, or methyldopa, or in rare circumstances you might need to be admitted for intravenous (IV) treatment. It is believed that pre-eclampsia will resolve when the placentais birthed although, as already mentioned, some women develop post-natal pre-eclampsia and, for those diagnosed antenatally, they might still require medication postnatally for a period of time. "It is likely that any woman diagnosed with pre-eclampsia in pregnancy will be offered an induction of labour from 37 weeks but this will be a decision made between you and your healthcare team, however, if suffering from severe pre-eclampsia you might be advised to birth your baby even earlier," Lesley says.

You will be offered extra appointments during your pregnancy for regular BP checks, medicine reviews, blood tests, electronic fetal monitoring (CTG) to assess baby’s wellbeing, and will be advised to have additional ultrasound scansto monitor your baby’s growth, and dopplers which measure the blood flow between mum and baby. "It is important that you understand the importance of attending these additional appointments and of adhering to any medication you have been prescribed." adds Lesley.

Meet the expert:

Lesley Gilchrist from My Expert Midwife started her path to midwifery in 1997 when she started training to be a nurse in Glasgow. On graduation, she moved to England and worked on the Cardiothoracic Intensive Care ward in Newcastle, working with patients undergoing heart and lung transplants. Lesley’s mum had been a midwife and she had always been fascinated by pregnancy and birth and so started midwifery training at Northumbria University. Lesley’s training at South Tyneside General Hospital gave her a good grounding in woman-centred care and on graduation she moved to the RVI in Newcastle, a large referral unit, working on the antenatal and postnatal wards before moving to the labour ward. Here she experienced caring for a large range of women, including those who went into labour early on in their pregnancies and very poorly women. At the same time Lesley was working on major research projects on the time limits for the second stage of labour. On completion of her studies, Lesley wanted to create a role for herself that allowed for holistic care for women before, during and after birth, which led to her becoming an independent midwife. It was during this time she started to develop products that could help women during pregnancy and help them to recover following birth.

Mummy to a little girl, Adejumoke Ilori is Commercial Content Writer for Mother&Baby. With a BA hon in Creative Writing, she has worked for digital platforms, where she has empowered women from the inside and out, by sharing real life stories based on relationships, loving yourself and mummyhood.

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