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Hypertension And Pregnancy – Preparing For Pregnancy

Hypertension is the medical term for high blood pressure. Having high blood pressure has significant health risks and increases the chance of heart attack and other acute vascular disorders including, but not limited to, stroke. Controlling one’s blood pressure and maintaining it within a healthy range is important throughout one’s life but is especially so during pregnancy when the body experiences exceptional and sometimes acute and/or chronic stresses.

Emotional stress, too, can have an impact on blood pressure and pregnancy can be an extremely tense experience for some women. Like many medical conditions some women already suffer from high blood pressure before they get pregnant while, for others, pregnancy can induce the condition: this is known as gestational hypertension.

1. Pregnancy in women with existing high blood pressure (hypertension)

Between one and three pregnant women per one hundred already suffer with high blood pressure before they get pregnant. Usually, hypertension is managed with lifestyle changes such as increasing exercise levels, eating healthily, reducing or abstaining from alcohol and caffeine and cessation of smoking.

For some though, those measures alone are inadequate and medication is required. Many of the drugs used in hypertensive patients are unsuitable for use during pregnancy as they restrict the volume of blood reaching the placenta and, therefore, the amount of oxygen and nutrients reaching the developing baby. You must not, however, suddenly stop taking any prescribed medication.

If you are planning to become pregnant and suffer with hypertension consult with your doctor who will manage a change in your medication schedule. If you discover you are pregnant while taking anti-hypertensives then see your doctor promptly to discuss what steps you must take to increase the chances of a safe and successful pregnancy.

2. Pregnancy onset hypertension (gestational hypertension)


Between five and ten percent of women who have never been diagnosed with hypertension previously are diagnosed as suffering with high blood pressure resulting from pregnancy. This is caused by the additional demands placed upon the body as the baby grows and develops in the uterus.

Pre-eclampsia (or more correctly, pre-eclamptic toxaemia) is a condition that occurs late in pregnancy – sometimes beginning just before or at labour – whereby the maternal blood pressure can reach extremely dangerous levels very quickly indeed.

Recognising the signs and symptoms of pre-eclampsia could save your’s and your baby’s life. Without treatment pre-eclampsia can lead to seizures in the mother that can starve the baby of oxygen, which can, in turn, result in the baby being permanently brain damaged or its death. Unrecognised and, therefore, untreated pre-eclampsia can also result in maternal death and significantly increases her risk of stroke and of liver and kidney damage.

In most cases pre-eclampsia only occurs after the twenty eighth week of pregnancy but it may, in rare instances, begin earlier and evidence suggests the more severe cases have an earlier onset. More rarely, the onset pre-eclampsia can begin after birth. It is vital, particularly if you have suffered with hypertension in the past or suffer with it currently, that your blood pressure is monitored closely after delivering your baby.

Pre-eclampsia affects around 10% of all pregnancies and women with a history of hypertension are more at risk if developing the condition than others. Measures in place to detect pre-eclampsia are blood pressure monitoring and checking for protein in the urine. These two checks should be part of every antenatal appointment. Most often, pre-eclampsia is mild and has few or no symptoms.

However, there are the symptoms you should look out for that could indicate pregnancy onset hypertension or pre-eclampsia.

  • Severe or constant head ache
  • Pain just below the rib area
  • Nausea and vomiting
  • Sudden swelling particularly in the face, hands and wrists
  • Blurring of vision or other visual disturbances.

Should the team of professionals responsible for you care deem you are suffering from severe pre-eclampsia late in your pregnancy, they may advise you have your baby early and offer to induce your labour to minimise the risk inherent in this condition for you and your baby.

pregnancy high blood pressure

3. Who is most at risk of developing pregnancy onset hypertension and/or pre-eclampsia?

Women with a history of hypertension are most at risk of developing pre-eclampsia during their pregnancy as are women who have suffered either of these conditions in previous pregnancies. Being overweight significantly increases the risks of developing both pre-eclampsia and pregnancy onset hypertension, as well as a host of other pregnancy-related complications such as gestational diabetes.

Indeed, study after study has indicated that these risks increase the more overweight the mother is. It is, perhaps, more essential when preparing for and during pregnancy than at other times to eat a healthy, balanced diet and to keep one’s weight within a healthy range. In fact, it is recommended that women strive to bring their weight into healthy limits before conception to maximise the chances of a successful and uncomplicated pregnancy.

Taking regular exercise, abstaining from alcohol and quitting smoking are all sensible measures at any time of life but are particularly important steps to take during pregnancy and even when planning to conceive.

Decongestants found in many cold remedies that are often safe to take during pregnancy may have a stimulant effect and cause a rise in blood pressure. Women with a history of hypertension or pre-eclampsia in previous pregnancies should avoid these unless directed otherwise by their physician.

4. Caffeine

Caffeine, the drug found in tea, coffee and some soft drinks, particularly colas, is a stimulant and as such increases blood pressure. Many health agencies around the world advise cutting out caffeine during pregnancy for all women though this advice varies from country to country. It is best utterly avoided during pregnancy if you are deemed to be in a group more at risk for developing pregnancy onset hypertension and/or pre-eclampsia.

Midwife sonographer facilitated

Consultant Led, Centre of Medical Excellence 


All articles on the blog and website are intended as information only. Please do not consider any of the information provided here as a substitute for medical advice. At all times seek medical advice directly with your own doctor and medical team.


This website was formerly Merrion Fetal Health. The clinic has undergone a rebrand and is now known as Merrion Ultrasound.