Risk factors for pre-eclampsia and fetal growth restriction

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What is pre-eclampsia?

Pre-eclampsia is a complication that occurs in 5 to 8% of pregnancies. It involves a rise in blood pressure which is accompanied by a leakage of protein from the kidneys into your urine. This protein can be detected by testing your urine at each antenatal visit. In severe cases, headaches, visual disturbances, stomach pain, facial swelling and nausea may occur.

Why am I being offered aspirin?

Aspirin belongs to a group of drugs called antiplatelet drugs: these drugs stop the platelets in your blood sticking together so you are less likely to get blood clots. If you are otherwise healthy there are no known concerning risks or side effects to you or your unborn baby.

During pregnancy and the post-natal period, some women / people have an increased chance of developing pre-eclampsia and / or fetal growth restriction (see explanation of these conditions below). Midwives assess all pregnant women/people at booking regarding their chances of developing pre-eclampsia, or fetal growth restriction. Often, these conditions co-exist and risk factors overlap.

Those with risk factors who may be more likely to develop these conditions will be advised to take 150mgs of Aspirin daily by mouth, from 12 to 16 weeks of pregnancy until 36 weeks of
pregnancy as there is evidence this can help lower the chances of developing the conditions.

Aspirin 150mg can be bought over the counter or your GP / obstetrician can provide a prescription.

Am I at risk for developing pre-eclampsia?

Pre-eclampsia can occur in any pregnancy but you are at higher risk if your blood pressure has already been high before you became pregnant, or if your blood pressure was high in a previous pregnancy.

If you have a medical disorder such as diabetes or a kidney condition, or if you have a condition that affects the immune system such as lupus, you are at a higher risk of developing pre-eclampsia.

The importance of other risk factors is less known, but generally you are more likely to develop pre-eclampsia if you have 2 of the following:

• Aged 40 or over.
• This is your first pregnancy.
• It is more than 10 years since your last pregnancy.
• Your BMI is 35 or more.
• You have a family history of pre-eclampsia.
• If you are expecting twins / triplets.

What is fetal growth restriction?

Babies who are small for gestational age (SGA) or very small, referred to as, fetal growth restriction (FGR) do not do as well through pregnancy and labour. Smaller babies with a lower body weight do not have the energy reserves to cope with any stress that they may incur.
Antenatal detection of growth restricted babies is vital and has been shown to reduce stillbirth risk.

Am I at risk of developing fetal growth restriction?

Fetal growth restriction is more likely if you have had a previously small / growth restricted baby, or any of the below risk factors:
• Smoking in pregnancy, or taking recreational drugs.
• Aged over 40 years.
• Other medical disorder such as diabetes, a kidney condition, or if you have a condition that affects the immune system such as lupus.
• Previously had a pregnancy affected by high BP or pre-eclampsia.
• Previous stillbirth related to fetal growth issues.
• Low PAPP-A level (blood test checked during the early combined screening test): the screening team will contact you about this if it is found to be low.

Will I need any other tests for pre-eclampsia or fetal growth restriction?

If you have any of these risk factors, you will be referred to the obstetric antenatal clinic for planning the pregnancy.

You may be offered an extra scan performed at the time of the anomaly (20 weeks) scan to check the uterine artery Dopplers (UADs). This assesses the flow of blood in the vessels which supply the uterus (womb) and can provide an indication as to whether the baby will grow to its full potential or raise the possibility of developing pre-eclampsia.

Very rarely the sonographer may not be able to obtain your UAD’s. According to the results, your consultant will discuss the on-going care plan for you including extra growth scans in the third trimester.

Who do I get in touch with for more information?

For more information, speak with your midwife or GP or phone 01273 664794.

At the end of the leaflet is a form for the patient to complete and sign. Please print off the PDF version to obtain the form.