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Low PAPP-A

PAPP-A (Pregnancy-Associated Plasma Protein-A) is a protein produced by the placenta in early pregnancy, helping with fetal growth and development. Low PAPP-A levels may be linked to complications like restricted fetal growth, pre-eclampsia, and an increased risk of miscarriage, but it can also occur in normal pregnancies

Low PAPP-A: Key Information

Low PAPP-A (Pregnancy-Associated Plasma Protein-A) means that the placenta may not be working as well as it should, which can affect the baby’s growth and pregnancy health. It is usually detected during the first-trimester combined screening test for Down’s syndrome. While most pregnancies with low PAPP-A progress normally, studies suggest it may be linked to a higher risk of restricted fetal growth (IUGR), pre-eclampsia, preterm birth, and stillbirth. Because of this, women with low PAPP-A are often monitored more closely with extra ultrasound scans to check the baby’s growth and placenta function.

The NHS considers a PAPP-A level below 0.41 MoM (multiples of the median) as low, which may require additional care. Women with low PAPP-A are usually offered extra growth scans in the third trimester to track the baby’s development and ensure the placenta is functioning properly. If other risk factors are present, some may be advised to take low-dose aspirin to improve blood flow to the placenta and reduce complications. However, low PAPP-A alone does not always mean there will be problems, and most babies are born healthy. If you have concerns, speak to your midwife or obstetrician about your individual pregnancy care plan.

3rd Trimester Growth Scan

Low PAPP-A pregnancies are recommended additional scans in the 3rd Trimester

Low PAPP-A Statistics and facts

  • Prevalence: Low PAPP-A (Pregnancy-Associated Plasma Protein-A) is detected in around 1 in 20 pregnancies in the UK, with levels below 0.41 MoM (multiples of the median) considered low.

  • Function: PAPP-A is a protein produced by the placenta that plays a crucial role in fetal growth and development, particularly in early pregnancy.

  • Risk factors: Women over 35 years, those with high BMI, pre-existing hypertension, multiple pregnancies, or a history of pregnancy complications may be more likely to have low PAPP-A.

  • Potential complications: While many pregnancies with low PAPP-A progress normally, it has been associated with an increased risk of intrauterine growth restriction (IUGR), pre-eclampsia, preterm birth, and, in rare cases, stillbirth.

  • NHS guidelines: The NHS offers extra growth scans in the third trimester for women with low PAPP-A to monitor fetal development and placental function. In some cases, low-dose aspirin may be recommended to improve blood flow to the placenta and reduce risks.

  • Birth outcomes: Most women with low PAPP-A have healthy pregnancies and babies, but close monitoring helps detect any complications early. If concerns arise, obstetricians may recommend early delivery or induction to ensure the baby’s safety.

Most Low PAPP-A Pregnancies result in healthy babies

Despite these associations, most pregnancies with low PAPP-A result in normal outcomes. Many women with low PAPP-A experience no complications, carry their pregnancy to full term, and give birth to healthy babies. The presence of low PAPP-A alone does not guarantee problems but rather serves as an early indicator for healthcare providers to monitor pregnancy more closely. Additionally, PAPP-A is used as part of the first-trimester combined screening test for chromosomal conditions like Down’s syndrome (Trisomy 21), Edwards’ syndrome (Trisomy 18), and Patau’s syndrome (Trisomy 13). Lower levels of PAPP-A, combined with abnormal hCG and nuchal translucency measurements, could indicate a higher likelihood of these conditions. At London Pregnancy clinic, we prefer using the more modern approach of NIPT (Non-Invasive Prenatal Testing) as a screening test for chromosomal abnormalities. Low PAPP-A alone does not confirm a genetic condition, and most babies with low PAPP-A levels are genetically normal and born healthy.

Informational image by London Pregnancy Clinic showing the advantages of NIPT over traditional screening methods with statistics on false positives.

As always, NIPT is the best way to screen for chromosomal abnormalities

Frequently Asked Questions

Your questions answered

What is PAPP-A and why is it important in pregnancy?

PAPP-A (Pregnancy-Associated Plasma Protein-A) is a protein produced by the placenta in early pregnancy. It plays a key role in placental development and blood flow, ensuring that the baby receives enough oxygen and nutrients to grow properly. PAPP-A levels are measured as part of the first-trimester screening test, which checks for chromosomal conditions like Down’s syndrome (Trisomy 21), Edwards’ syndrome (Trisomy 18), and Patau’s syndrome (Trisomy 13). Although low PAPP-A levels can sometimes indicate a higher risk of complications, most pregnancies with low PAPP-A progress normally.

Low PAPP-A is not a diagnosis but rather a risk marker, meaning that it helps doctors identify pregnancies that may require extra monitoring. If your PAPP-A levels are low, your healthcare provider may recommend additional ultrasound scans in the third trimester to check your baby’s growth and placental function. In some cases, low-dose aspirin may be prescribed to improve blood flow to the placenta and lower the risk of complications.

What does it mean if I have low PAPP-A?

f your PAPP-A levels are below 0.41 MoM (multiples of the median), this is considered low and may suggest that your placenta is not working as efficiently as expected. While many women with low PAPP-A have completely normal pregnancies, some are at a slightly higher risk of intrauterine growth restriction (IUGR), pre-eclampsia, preterm birth, and stillbirth. Because of this, extra growth scans are recommended in the third trimester to ensure your baby is developing well.

It’s important to remember that low PAPP-A does not mean your baby will have a problem, only that there is a higher possibility of certain complications. Most babies with low PAPP-A are born healthy and do not experience any issues. If you have concerns, speak to your midwife or obstetrician, who can tailor a pregnancy care plan based on your individual needs.

Does low PAPP-A mean my baby has a genetic condition?

Low PAPP-A alone does not mean your baby has a genetic condition, but it is one of the markers used in first-trimester screening for chromosomal abnormalities. The NHS combined screening test assesses the risk of Down’s syndrome, Edwards’ syndrome, and Patau’s syndrome by measuring PAPP-A and hCG levels along with the nuchal translucency scan. If the combined results show a higher risk, your doctor may recommend Non-Invasive Prenatal Testing (NIPT) or amniocentesis for a more accurate screening or diagnosis.

However, the majority of women with low PAPP-A have babies without genetic abnormalities. Low PAPP-A can occur without any underlying cause and does not always indicate a problem. If your screening test results are normal, there is usually no reason to worry about genetic conditions.

How does the NHS manage pregnancies with low PAPP-A?

The NHS recommends additional monitoring for women with low PAPP-A to ensure the baby continues to grow well. This usually includes extra ultrasound scans in the third trimester to check the baby’s growth, amniotic fluid levels, and blood flow in the placenta. If any concerns arise, your obstetrician may discuss early delivery options or induction of labour to keep both you and your baby safe.

In some cases, low-dose aspirin (150mg per day) may be recommended to improve blood circulation to the placenta and reduce the risk of pre-eclampsia and growth restriction. However, most pregnancies with low PAPP-A progress without complications, and these extra measures are mainly taken as a precaution.

Can I do anything to increase my PAPP-A levels?

Currently, there is no proven way to increase PAPP-A levels once they have been measured in early pregnancy. However, certain lifestyle choices may help support placental health and overall pregnancy well-being. Eating a balanced diet rich in protein, iron, and healthy fats, staying well-hydrated, and engaging in gentle exercise (if advised by your doctor) can all contribute to a healthy placenta and baby.

If your doctor recommends taking low-dose aspirin, it’s important to follow their advice, as this has been shown to improve placental blood flow and reduce pregnancy complications. Most importantly, attending all scheduled scans and appointments will ensure that any potential issues are identified early and managed appropriately.

Will low PAPP-A affect my baby’s growth?

In most cases, low PAPP-A does not affect the baby’s growth, and many women go on to have completely healthy babies. However, some studies suggest that low PAPP-A may be linked to intrauterine growth restriction (IUGR), meaning the baby may grow more slowly than expected. This is why extra growth scans are recommended in later pregnancy for women with low PAPP-A.

If growth restriction is detected, your healthcare team will closely monitor your baby’s progress and may suggest early delivery if necessary. However, most babies with low PAPP-A grow normally, and the additional scans are simply a precaution to ensure your baby continues to thrive.

Does low PAPP-A mean I will have pre-eclampsia?

Low PAPP-A is considered a risk factor for pre-eclampsia, but it does not mean you will definitely develop the condition. Pre-eclampsia is a pregnancy complication caused by problems with the placenta, leading to high blood pressure and potential organ damage. Because PAPP-A is involved in placental development, low levels may indicate a slightly higher risk of pre-eclampsia, particularly if combined with other risk factors like high BMI, maternal age over 35, or a history of hypertension.

To reduce the risk, some women with low PAPP-A are advised to take low-dose aspirin daily from 12 weeks until birth. Regular blood pressure checks and third-trimester growth scans also help detect any early signs of pre-eclampsia. While the risk may be slightly higher, most women with low PAPP-A do not develop pre-eclampsia, and careful monitoring helps ensure a safe pregnancy and delivery.

Do you want to know more about your options of NIPT?