High blood pressure (hypertension) and Pregnancy
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High blood pressure (hypertension) is a common condition in which the long-term force of the blood against your artery walls is high enough that it may eventually cause health problems, such as heart disease. High blood pressure, or hypertension, does not usually make you feel unwell, but it can sometimes be serious in pregnancy.
Due to CDC;
- Nearly half of adults in the United States (108 million, or 45%) have hypertension.
- Only about 1 in 4 adults (24%) with hypertension have their condition under control.
- About half of adults (45%) with uncontrolled hypertension have a blood pressure of 140/90 mm Hg or higher. This includes 37 million U.S. adults.
- About 30 million adults who are recommended to take medication may need it to be prescribed and to start taking it. Almost two out of three of this group (19 million) have a blood pressure of 140/90 mm Hg or higher.
- High blood pressure was a primary or contributing cause of death for more than 494,873 people in the United States in 2018.
- High blood pressure costs the United States about $131 billion each year, averaged over 12 years from 2003 to 2014.
Your midwife will check your blood pressure at all your antenatal (pregnancy) appointments.
If you are pregnant and have a history of high blood pressure, you should be referred to a specialist in hypertension and pregnancy to discuss the risks and benefits of treatment.
If you develop high blood pressure for the first time in pregnancy, you will be assessed in a hospital by a healthcare professional, usually, a midwife, who is trained in caring for raised blood pressure in pregnancy.
What is high blood pressure?
There are 3 levels of hypertension:
- Mild – blood pressure between 140/90 and 149/99mmHg (millimetres of mercury); may be checked regularly but does not usually need treatment
- Moderate – blood pressure between 150/100 and 159/109mmHg
- Severe – blood pressure of 160/110mmHg or higher
What are types of high blood pressure conditions before, during, and after pregnancy?
Your doctor or nurse should look for these conditions before, during, and after pregnancy:
Chronic hypertension means having high blood pressure* before you get pregnant or before 20 weeks of pregnancy. Women who have chronic hypertension can also get preeclampsia in the second or third trimester of pregnancy.
This condition happens when you only have high blood pressure during pregnancy and do not have protein in your urine or other heart or kidney problems. It is typically diagnosed after 20 weeks of pregnancy or close to delivery. Gestational hypertension usually goes away after you give birth. However, some women with gestational hypertension have a higher risk of developing chronic hypertension in the future.
Pre-eclampsia happens when a woman who previously had normal blood pressure suddenly develops high blood pressure and protein in her urine or other problems after 20 weeks of pregnancy. Women who have chronic hypertension can also get preeclampsia.
Preeclampsia happens in about 1 in 25 pregnancies in the United States. Some women with preeclampsia can develop seizures. This is called eclampsia, which is a medical emergency.
Symptoms of preeclampsia include:
- A headache that will not go away
- Changes in vision, including blurry vision, seeing spots, or having changes in eyesight
- Pain in the upper stomach area
- Nausea or vomiting
- Swelling of the face or hands
- Sudden weight gain
- Trouble breathing
- Some women have no symptoms of preeclampsia, which is why it is important to visit your health care team regularly, especially during pregnancy.
You are more at risk for preeclampsia if:
- This is the first time you have given birth.
- You had preeclampsia during a previous pregnancy.
- You have chronic (long-term) high blood pressure, chronic kidney disease, or both.
- You have a history of thrombophilia (a condition that increases risk of blood clots).
- You are pregnant with multiple babies (such as twins or triplets).
- You became pregnant using in vitro fertilization.
- You have a family history of preeclampsia.
- You have type 1 or type 2 diabetes.
- You have obesity.
- You have lupus (an autoimmune disease).
- You are older than 40.
In rare cases, preeclampsia can happen after you have given birth. This is a serious medical condition known as postpartum preeclampsia. It can happen in women without any history of preeclampsia during pregnancy. The symptoms of postpartum preeclampsia are similar to the symptoms of pre-eclampsia. Postpartum preeclampsia is typically diagnosed within 48 hours after delivery but can happen up to 6 weeks later.
Tell your health care provider or call 9-1-1 (or your local emergency line) right away if you have symptoms of postpartum preeclampsia. You might need emergency medical care.
If you are already taking medicine for high blood pressure
If you’re already taking medicine to lower your blood pressure and want to try for a baby, talk to your physician first. They may want to switch you to a different medicine before you get pregnant.
If you find out you’re already pregnant, tell your doctor immediately. They may need to change your medicine as soon as possible.
This is because some medicines that treat high blood pressure may not be safe to take when you’re pregnant. They can reduce the blood flow to the placenta and your baby, or affect your baby in other ways.
Your pregnancy appointments
It’s important that your antenatal team monitors you closely throughout your pregnancy to make sure your high blood pressure is not affecting the growth of your baby and to check for a condition called pre-eclampsia. Make sure you go to all your appointments.
Your doctor or midwife will measure your blood pressure and check for protein in your urine. After 20 weeks of pregnancy, you may be offered a PlGF (placental growth factor) test to rule out pre-eclampsia.
During the first half of pregnancy, a woman’s blood pressure tends to fall. This means you may be able to come off your medicine for a while. But this should only be done under your doctor’s supervision.
Things you can try yourself to reduce high blood pressure
Keeping active and doing some physical activity each day, such as walking or swimming, can help keep your blood pressure in the normal range. Eating a balanced diet and keeping your salt intake low can help to reduce blood pressure.
There isn’t enough evidence to show that dietary supplements – such as magnesium, folic acid or fish oils – are effective at preventing high blood pressure.
Labour and birth
If you’re taking medicine throughout pregnancy to control your blood pressure, keep taking it during labour.
If you have mild or moderate hypertension, your blood pressure should be monitored hourly during labour. As long as your blood pressure remains within target levels, you should be able to have a natural vaginal birth.
If you have severe hypertension, your blood pressure will be monitored every 15 to 30 minutes in labour. Your doctors may also recommend your baby be delivered using forceps or ventouse, or by caesarean section.
After the birth, your blood pressure will be monitored.
If you had hypertension before you got pregnant, your treatment should be checked 2 weeks after your baby is born.
Check-ups after the birth
If you developed hypertension while you were pregnant and you’re still taking medicine after the birth, you should be offered an appointment with a doctor 2 weeks after you transfer from hospital care to community midwives, or 2 weeks after the birth if you had a home birth.
This is to check whether your treatment needs to be changed or stopped.
Everyone with hypertension in pregnancy should also be offered an appointment with a GP or specialist 6 to 8 weeks after their baby is born.
This appointment is to check your blood pressure and is separate from your 6-week postnatal check.
You should be able to breastfeed if you need to take hypertension medicine. Your treatment can be changed if needed, in agreement with your doctor.
Hypertension medicines can pass into breast milk. Most lead to very low levels of breast milk, and the amount taken in by babies is very small.
Most medicines are not tested during pregnancy or breastfeeding. Disclaimers or warnings in the manufacturer’s information are not because of specific safety concerns or evidence of harm.
Find out about specific medicines and pregnancy at the website for Bumps (Best use of medicines in pregnancy).
Talk to your midwife or doctor about breastfeeding if you’re taking medicine.