Preeclampsia: Hypertension in Pregnancy

As you might have read from the previous edition, hypertension develops when narrow blood arteries create more resistance to blood flow. In today's edition of The Missing Link, you will be learning about hypertension in pregnancy.

Hypertension does not usually make you sick, but it can often lead to some fatal problems during pregnancy.

A woman that has high blood pressure during pregnancy needs close monitoring, her midwife will have to check her blood pressure at all her antenatal appointments.

In most cases, if the pregnant woman has a history of hypertension, you should refer her to a specialist in hypertension and pregnancy so the specialist can discuss the risks and best treatment. If the woman is developing high blood pressure for the first time in pregnancy, then you have to refer her to a healthcare professional, often a midwife, who is trained in caring for high blood pressure in pregnancy.

Categories of high blood pressure

There are 3 categories of high blood pressure:

• Stage 1 hypertension: The systolic number is between 130 and 139 mm Hg, and the diastolic number is between 80 and 89 mm Hg.?
• Stage 2 hypertension: The systolic number is 140 mm Hg or higher, and the diastolic number is 90 mm Hg or higher.?
• Hypertensive crisis: The systolic number is over 180 mm Hg, and the diastolic number is over 120 mm Hg.?

Stage 2 hypertension has 3 levels:

• Mild hypertension occurs when blood pressure is between 140/90 and 149/99mmHg.
• Moderate hypertension occurs when blood pressure is between 150/100 and 159/109mmHg
• Severe hypertension happens when blood pressure is 160/110mmHg or higher.

How to reduce your hypertensive patient's and her baby's risks of having complications during pregnancy

Remember to tell your patient to talk to you or any general practitioner or specialist first if she wants to try for a baby and is already taking medicine to lower her blood pressure before pregnancy.?

That way, you will be able to switch her to a different medication before she gets pregnant if necessary.

You should recommend a preconception appointment with a healthcare provider who is a specialist in managing pregnancies complicated by hypertensive disorders.?

You should also advise your patient to keep in touch with you.?

And if they're overweight, advise them to lose weight before becoming pregnant.

You should also ask her to tell you or any general practitioner or specialist if she finds out that she is already pregnant so that you can change her medication as soon as possible.

It is necessary to change some high blood pressure medications during pregnancy because some of these medications may not be safe to take when a woman is pregnant because they can reduce the blood flow to the placenta and the baby, or affect the baby in other vital ways.

Types of hypertension during pregnancy

As you've read above, sometimes a woman has a history of hypertension before pregnancy.

In other cases, the blood pressure rises during pregnancy. Here are the four types of hypertension that develop during pregnancy;

• Chronic hypertension: develops either before pregnancy or during the first 20 weeks of pregnancy.? It is quite hard to know exactly when it began since hypertension does not usually have symptoms.
• Chronic hypertension with superimposed preeclampsia: this happens when chronic hypertension leads to worsening hypertension during pregnancy. Pregnant women with this condition may develop protein in the urine or other complications.
• Gestational hypertension: develops after the first 20 weeks of pregnancy. Although there is no excess protein in the urine and there are no other signs of organ damage, gestational hypertension can lead to preeclampsia.
• Preeclampsia: occurs when hypertension develops after the first 20 weeks of pregnancy.?

Preeclampsia might be associated with signs of damage to other organ systems, including the kidneys, liver, blood, or brain.

Untreated preeclampsia can lead to fatal complications for the mother and baby. Complications may include eclampsia, in which seizures develop.

This is why it's important to measure your patient's blood pressure after the first 20 weeks of pregnancy, and offer a placental growth factor(PlGF) test to rule out preeclampsia.

You must also know that checking your patient's urine for protein won't tell you whether or not they have preeclampsia because preeclampsia can be diagnosed with or without having protein in the urine.

It is also essential to check if your patient's blood pressure falls during the first half of pregnancy. If her blood pressure falls, you have to decide whether or not she should stop her medications.

Symptoms of preeclampsia

Hypertension and having protein in your urine are one of the major symptoms of preeclampsia but there are others symptoms of preeclampsia. Other signs and symptoms of preeclampsia include:

• Extra protein in the urine or other signs of kidney problems
• Severe headaches
• Temporary loss of vision, blurred vision, or sensitivity to light
• Upper stomach pain, usually under the ribs on the right side
• Nausea
• Decreased levels of platelets in the blood
• Impaired liver function
• Shortness of breath, caused by fluid in the lungs
• Sudden weight gain and swelling — particularly in the face and hands — often occur with preeclampsia. The swelling associated with preeclampsia is more severe than the typical swelling during pregnancy.

What should your hypertensive pregnant patient's antenatal visits include?

• Frequent laboratory tests.
• Checking weight and blood pressure at every visit.
• Frequent ultrasounds to monitor her baby's health and track growth.?
• Fetal testing to evaluate her baby's well-being.?

Why is hypertension a fatal problem during pregnancy?

Hypertension during pregnancy leads to various fatal risks, especially for the baby. Some of these risks are as follows:

• Less blood flow to the placenta: Hypertension in pregnancy leads to less blood flow to the placenta.?If the placenta doesn't get enough blood, then the fetus might receive less oxygen and fewer nutrients. This can lead to intrauterine growth restriction, low birth weight, or premature birth, and babies born early can have breathing problems, increased risk of infection, and other complications.
• Placental abruption: Placental abruption separates the placental from the inner wall of the uterus before delivery. Preeclampsia and hypertension increase the risk of placental abruption. Severe abruption may lead to heavy bleeding, which can be life-threatening for your patient and her baby.
• Intrauterine growth restriction: This occurs when high blood pressure slows or decreases fetal growth.
• Injury to other organs: Hypertension that is not well taken care of during pregnancy can cause injury to the brain, eyes, lungs, heart, kidneys, and other major organs. In severe cases, it can be life-threatening.
• Premature delivery: When life-threatening complications are predicted or surface, early delivery is needed to prevent further damage.
• Future cardiovascular disease: A woman that has preeclampsia might be more prone to having future heart and cardiovascular disease. The risk of future cardiovascular disease is higher if the woman has had preeclampsia more than once.

How to reduce the risk of complications

The best way your patient can reduce the risk of the above complications is by taking good care of herself. Others include:

• Showing up for antenatal appointments
• Taking blood pressure medication and low-dose daily aspirin as prescribed.
• Staying active and following recommendations for physical activity.
• Eating a healthy diet.
• Avoiding smoking, alcohol, and illegal drugs.?
• Talking to a health practitioner before taking medications that are not prescribed.

How to prevent preeclampsia

Scientists continue to study the different ways to prevent preeclampsia. Some studies show that taking low-dose aspirin (81 milligrams) daily lowers the risk of preeclampsia in those who are at high risk.

How does having hypertension affect labour and birth?

You should strongly advise your hypertensive pregnant patient to give birth in a standard hospital with the support of a consultant-led maternity team.

It is also highly recommended that your patient has induced labour before her due date to avoid complications.

The timing of the induced birth is based on how well-controlled the blood pressure is, whether she has end-stage organ damage and whether her baby has complications.

There are 6 things you want to make sure of during labour:?

1. If your patient is taking medication throughout pregnancy to control her blood pressure, she has to keep taking it during labour.
2. If your patient has mild or moderate hypertension, her blood pressure should be monitored hourly during labour.
3. If her blood pressure remains within target levels, she should be able to have a natural vaginal birth.
4. If your patient has preeclampsia and her condition is getting worse, you might have to recommend medication during labour to help prevent seizures.
5. If your patient has severe hypertension, her blood pressure will be monitored every 15 to 30 minutes in labour.?
6. You should recommend for her baby to be delivered using forceps or ventouse, or by caesarean section.

Can a mother with hypertension breastfeed her baby?

Breastfeeding is encouraged for most women who have hypertension, even those who take medication. But just like before pregnancy, you must make sure the medications your patient is taking are harmless to her baby.

Should your hypertensive patient come for appointments after giving birth?

If your patient has hypertension before pregnancy, she should get back to her usual treatment 2 weeks after giving birth.

If your patient developed hypertension during pregnancy and is still taking medications after the birth, you should offer her an appointment 2 weeks after the birth to check her blood pressure and to check whether her treatment needs to be changed or stopped.

This appointment should go on for 6 to 8 weeks after the baby is born.

I hope this edition of The Missing Link has been enlightening and that you can use the information in this newsletter to serve your hypertensive patients during pregnancy better.

I am Helen Fosam , a medical writer passionate about improving health outcomes through continuing medical education in Africa.

To learn more about our courses and what we do, connect with The MiLHO Initiative and check out our website https://milho.net/ to learn more about hypertension.

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Research Credits:?

NHS: https://www.nhs.uk/pregnancy/related-conditions/complications/high-blood-pressure/

Mayo Clinic: https://www.mayoclinic.org/healthy-lifestyle/pregnancy-week-by-week/in-depth/pregnancy/art-20046098#:~:text=High%20blood%20pressure%20during%20pregnancy%20poses%20the%20following%20risks%3A,birth%20weight%20or%20premature%20birth.