High-blood pressure and miscarriage

You may have read reports recently of a US study that appears to link high-blood pressure before pregnancy to miscarriage. We explain more about how this study was made and what it means.

Tommy's news, 04/04/2018

A recent study in the US has made the link between women with slightly elevated blood pressure before pregnancy and an increased risk of miscarriage.

This headline has since been picked up and shared by the UK media. If you are anxious as to how your blood pressure might affect your pregnancy, we want to reassure you that while this study does identify a potential risk factor for miscarriage, it does not prove a conclusive link between elevated high blood pressure and miscarriage. 

'Pregnancy loss is not well understood yet. The authors found an association of hypertension and pregnancy loss which was independent of the age or weight of the women. We cannot be certain that hypertension per se causes miscarriage but we know it causes several obstetric complications and now can also be considered a risk factor for pregnancy loss.'

Clinician Scientist at Tommy's National Centre for Miscarriage Research, Dr Loannis Gallos

Here are the facts about the recent report:

  • The study wasn’t a controlled experiment designed to prove whether or how slight elevations in blood pressure might contribute to miscarriage

  • Researchers lacked data to examine the connection between blood pressure and different types of pregnancy loss.

  • All the women who participated in the survey had experienced a previous miscarriage, it is possible these results might not apply to women who have a history of pregnancy loss. 

Whilst it’s important that studies continue to be conducted into the causes of pregnancy loss, it can be very worrying for women and their partners who are expecting a baby, and may have suffered miscarriages previously, to read broad statements in the media. Remember that if you are every worried about something you read or hear, you can get in touch with us at Tommy’s to talk it through. We have world renowned experts at our four centres in the UK who can check and verify reports from around the world, and a team of midwives who can talk you through the best options for you and your health.

If you are pregnant and anxious about your blood pressure, go to see your GP as soon as you can so you can get the support that you need.

Our midwife Sophie says if you are worried about your blood pressure, there are a few things you can do to manage your risk: 

Managing your blood pressure

Having high blood pressure is not always down to controllable factors both pre and during pregnancy- but if you keep active and get some physical activity each day, such as walking/swimming/yoga, this will help to reduce your risk of developing high BP.

Also, eating a healthy, balanced diet  and keeping your salt intake down can reduce your risk of developing this problem in the beginning.

While the type of treatment you are given for high blood pressure (if this is necessary) will depend on the cause of your high blood pressure, the key to a healthy pregnancy is to make sure that your blood pressure remains under control. Having check-ups with your antenatal team is the best way of monitoring your condition.

You should be offered additional antenatal appointments based on your needs and the needs of your baby.

Hypertension and Tommy's Research 

Hypertension, or high blood pressure, affects 10-15% of pregnancies and can increase the risk of complications for mother and baby. There are different types of hypertension in pregnancy. The most common are chronic hypertension and pre-eclampsia

In 2015, Tommy’s opened the Hypertension in Pregnancy Clinic at St. Thomas’ Hospital in London. Here, we research new ways to help women with chronic hypertension and provide specialist care to women suffering from high blood pressure.

Our current focus is providing care for women with chronic (pre-existing) hypertension in pregnancy, who are at particularly high risk of adverse outcomes in pregnancy, such as pre-eclampsia, preterm birth and delivering small for gestational age infants.

Read more about our research into Hypertension