Hypertension in Pregnancy

Dr. Panagiotis Polyzos, obstetrician gynecologist in Athens
Dr. Panagiotis Polyzos MD PhD MSc

Obstetrician-Gynecologist
PhD, University of Athens Medical School

Obstetrician-gynecologist Panagiotis Polyzos practices at the Institute of Life, the IVF Unit of IASO Maternity Hospital.

Contents

Hypertension in pregnancy

Hypertension in Pregnancy

What is hypertension?

Hypertension is defined as systolic blood pressure (SBP) above 140 mmHg or diastolic blood pressure (DBP) above 90 mmHg. In order to accurately diagnose arterial hypertension (AH), blood pressure (BP) must be elevated in at least two measurements taken at least 6 hours apart.

What is preeclampsia?

Preeclampsia is defined as the combination of hypertension during pregnancy and proteinuria (more than 300 mg of protein in a 24-hour urine sample).

Preeclampsia can present in a mild or severe form.

It is considered severe preeclampsia when the following are present:

  1. SBP above 160 mmHg or DBP above 110 mmHg
  2. Visual and neurological disturbances (blurred vision, dark spots, severe headache, and even altered consciousness)
  3. Symptoms of liver distention (pain in the stomach or right upper abdomen, nausea, vomiting)
  4. Impaired liver function (elevated liver enzymes on laboratory testing)
  5. Thrombocytopenia (severe decrease in platelet count)
  6. Pulmonary edema (shortness of breath, a feeling of choking)
  7. Increased serum creatinine (impaired kidney function)
  8. Reduced urine output (less than half a liter in 24 hours)
  9. Severe fetal growth restriction

Sometimes, high blood pressure is present before pregnancy. In other cases, high blood pressure develops during pregnancy.

Gestational hypertension: Women with gestational hypertension have high blood pressure that develops after 20 weeks of pregnancy. There is no excess protein in the urine or other signs of organ damage. Some women with gestational hypertension eventually develop preeclampsia.

Chronic hypertension: Chronic hypertension is high blood pressure that existed before pregnancy, or that appears before 20 weeks of pregnancy. But because high blood pressure usually has no symptoms, it can be difficult to determine when it started.

Chronic hypertension with superimposed preeclampsia: This condition occurs in women who had chronic hypertension before pregnancy and then develop worsening high blood pressure and protein in the urine, or other complications related to blood pressure, during pregnancy.

Preeclampsia: Preeclampsia occurs when high blood pressure develops after 20 weeks of pregnancy and is accompanied by signs of damage to various organs, including the kidneys, liver, blood, or brain. Without treatment, preeclampsia can lead to serious — even life-threatening — complications for both the mother and the baby, such as the development of seizures (eclampsia).

Find a solution to your problem.
Schedule your appointment

Reduced blood flow to the placenta. If the placenta does not receive enough blood, your baby may get less oxygen and fewer nutrients. This can lead to slow growth (intrauterine growth restriction), low birth weight, or premature birth. Premature delivery may result in breathing problems, an increased risk of infection, and other complications for the baby.

Placental abruption. Preeclampsia increases the risk of this condition, in which the placenta separates from the inner wall of your uterus before delivery. Severe abruption can cause heavy bleeding and may be life-threatening for both you and your baby.

Intrauterine growth restriction. High blood pressure can slow or reduce your baby's growth.

Damage to your other organs. Poorly controlled hypertension can damage the brain, heart, lungs, kidneys, liver and other major organs. In severe cases it can be life-threatening, and preterm delivery then becomes necessary.

Future cardiovascular disease. Preeclampsia can increase the risk of future heart and blood vessel (cardiovascular) disease. The risk of future cardiovascular disease is higher if you have had preeclampsia more than once or had a preterm delivery because of high blood pressure during pregnancy.

 

MEDIA

Follow us on YouTube

Prenatal screening during pregnancy
Interview on the TRT show “Kentriki Ellada Kalispera” (Good Evening, Central Greece)

Treatment of Preeclampsia

The goal of treatment is to maintain blood pressure at very good levels throughout the pregnancy, combined with continuous and thorough laboratory monitoring.

 

To manage high blood pressure in general, outside of pregnancy, antihypertensive medications are prescribed. Antihypertensive therapy is necessary in cases of severe hypertension, mainly to prevent cerebrovascular events.

 

Treating preeclampsia requires special caution, since aggressive management during pregnancy (e.g., sudden and uncontrolled decrease in blood pressure, early use of medication) may lead to maternal or fetal complications (e.g., stroke, myocardial ischemia, sudden intrauterine fetal death).

Find a solution to your problem.
Schedule your appointment

Monitoring During Pregnancy

Pregnant women must be informed promptly by their obstetrician about the signs and symptoms of preeclampsia and report them immediately if they appear. They should also contact their doctor right away in cases of vaginal bleeding, severe abdominal pain, reduced fetal movements, or symptoms of threatened preterm labor.

 

Strict bed rest is no longer recommended, because it does not improve pregnancy outcomes and increases the risk of blood clots. Your doctor will tell you what level of activity is safe for you.

 

Preventive low-dose aspirin (usually 75 to 150 mg a day), ideally started before week 16, in women at moderate or high risk of preeclampsia significantly reduces the risk of developing it. More on the use of Salospir in pregnancy can be found in the related article.

Systematic monitoring of the pregnant woman with hypertensive disease is essential and should take place at intervals of approximately every 2 weeks, and in some cases every week.

At each visit, blood pressure must be measured, fetal growth must be assessed via ultrasound, and a urine dipstick test performed.

Laboratory testing in hypertensive disease during pregnancy must be performed very regularly and includes:

  • Complete blood count
  • Urinalysis
  • Urea
  • Creatinine
  • Uric acid
  • Electrolytes
  • Liver enzymes: SGOT, SGPT, ALP, γGT, LDH
  • Coagulation profile

Fetal Monitoring

In hypertensive disorders of pregnancy, daily monitoring of fetal movements is recommended. Ultrasound assessment of fetal growth  is performed every 1–2 weeks.

 

Fetal development is monitored using a biophysical profile along with uterine artery blood flow assessment, ultrasound measurement of amniotic fluid volume and cardiotocography  (these tests are repeated at least weekly, or much more often if indicated). Doppler evaluation is essential for assessing fetuses with intrauterine growth restriction.

 

The administration of corticosteroids (betamethasone, CELESTONE CHRONODOSE) for enhancing fetal lung maturity before 34 weeks of gestation is mandatory in cases of mild or severe preeclampsia, as well as in cases of severe hypertension.

Vaginal Birth or Cesarean Section?

The definitive treatment for preeclampsia is the completion — termination — of the pregnancy.

When determining the timing of delivery, the risks to the mother and fetus, the gestational age, and the severity of the hypertensive disease are taken into consideration.

In cases of mild hypertension or preeclampsia without additional complications, delivery may be planned at a gestational age beyond 37 weeks.

In any case, delivery should not be delayed beyond 40 weeks. For severe hypertension or preeclampsia, delivery may be planned at 34 weeks of gestation, or earlier if clinically indicated.

Hypertensive disease in pregnancy — especially when the cervix is favorable — is not a contraindication to vaginal delivery, as long as the condition of the mother and fetus allows it and there are no other obstetric indications for cesarean section.

Prolonged labor should be avoided, especially in severe hypertension or preeclampsia.

In women with hypertensive disorders of pregnancy undergoing labor, we monitor at least every hour: vital signs, urine output/proteinuria, and any signs or symptoms of severe preeclampsia.

Routine laboratory tests are repeated at least every 6 hours.

The epidural and spinal anesthesia appear to be advantageous, provided there is no thrombocytopenia.

First trimester preeclampsia screening and prevention with aspirin

Preeclampsia can largely be predicted before it appears. At 11 to 14 weeks, along with the measurement of nuchal translucency, a risk calculation can be made that combines:

  • the woman's history (first pregnancy, previous preeclampsia, chronic hypertension, kidney disease, autoimmune diseases, IVF pregnancy),
  • mean arterial pressure,
  • blood flow in the uterine arteries with Doppler,
  • placental growth factor (PlGF) in the blood.

When the risk comes out high, low-dose aspirin every evening, started before 16 weeks and stopped around 36 weeks, significantly reduces the risk of preterm preeclampsia. In the large ASPRE trial, preterm preeclampsia was reduced by about half or more. The dose and duration are set by your doctor. Do not start aspirin on your own.

How to measure your blood pressure correctly at home

Home monitoring catches a rise in blood pressure early and avoids the falsely high readings often seen at the office. To make it reliable:

  • Use an upper arm monitor, not a wrist monitor, with a cuff of the right size for your arm.
  • Sit for five minutes before measuring, with your back supported and your feet flat on the floor, legs uncrossed.
  • Rest your arm on a table, at heart level.
  • Take two readings one minute apart and write them down.
  • Avoid coffee, smoking and exercise for half an hour beforehand.

What to do with your readings

  • Below 140/90: continue as instructed.
  • 140/90 or higher on two readings: let your doctor know the same day.
  • 160/110 or higher, or any high reading with headache, vision problems or pain in the upper abdomen: go to the maternity hospital immediately.

Blood pressure medication in pregnancy: what is allowed and what is not

Antihypertensive treatment in pregnancy has a dual goal: to protect the mother from stroke and other damage, and not to cause a sudden drop in blood flow to the placenta.

  • Safe and commonly used: labetalol, extended-release nifedipine and methyldopa.
  • Contraindicated: ACE inhibitors and sartans (ARBs), because they can harm the fetal kidneys. Diuretics are generally avoided.

If you have chronic hypertension and are planning a pregnancy, your medication should be changed before conception or as soon as the pregnancy is confirmed, always on medical advice. Do not stop your medications on your own.

In severe preeclampsia, intravenous magnesium sulfate is given at the maternity hospital. It does not lower blood pressure, but it prevents eclamptic seizures and protects the brain of the preterm newborn.

HELLP syndrome: the severe form that can look like a viral illness

HELLP syndrome is a serious complication linked to preeclampsia. Its name comes from the initials of its three findings: Hemolysis (destruction of red blood cells), Elevated Liver enzymes and Low Platelets.

The difficulty is that blood pressure may be only slightly raised or even normal. The symptoms often resemble gastroenteritis or the flu:

  • pain in the stomach area or under the right ribs,
  • nausea and vomiting,
  • marked malaise and fatigue,
  • headache.

In the third trimester, or in the first days after delivery, these symptoms need an urgent blood test at the maternity hospital. Do not put them down to something you ate. Treatment takes place in the hospital and usually includes delivery.

After delivery: why blood pressure still needs attention

Blood pressure does not always drop right after the birth. It often peaks 3 to 6 days later, when the mother has already gone home. Preeclampsia can even appear for the first time after delivery, up to six weeks later.

  • Keep measuring at home, as instructed when you were discharged from the maternity hospital.
  • Medication is reduced gradually and only on medical advice.
  • Most medications used after delivery are compatible with breastfeeding.
  • Headache, vision problems, shortness of breath or chest pain in the postpartum period need immediate assessment.

Heart health in the years ahead

A pregnancy with preeclampsia acts like a “stress test” for the blood vessels. That is why blood pressure checks at least once a year, cholesterol and blood sugar testing, maintaining a healthy weight and regular exercise are recommended. Tell every doctor who looks after you that you had high blood pressure in pregnancy. In a future pregnancy you will be offered early aspirin and closer monitoring, as is also the case for women with gestational diabetes (they also have an increased cardiometabolic risk).

Frequently Asked Questions

What blood pressure is considered high in pregnancy?

140/90 mmHg or higher, on two readings. Values of 160/110 or more are considered severe hypertension.

In preeclampsia, along with high blood pressure there is protein in the urine or organ involvement, such as the liver, the kidneys and the platelets.

Severe headache, vision problems, pain in the upper abdomen, sudden swelling of the face and hands. They need immediate assessment.

Yes, in most cases. The timing and type of delivery depend on the severity.

It usually returns to normal within weeks. However, future cardiovascular risk remains higher, which is why regular checkups are recommended.

Strict bed rest is not recommended, because it has not been shown to improve outcomes and it increases the risk of blood clots. You may be advised to limit strenuous activity and rest more, depending on the severity.

It is a blood test that measures two substances produced by the placenta. It is used in women with suspected preeclampsia after 20 weeks and mainly helps rule out its onset in the following days, so that unnecessary hospital admissions are avoided.

The likelihood is higher, especially if the preeclampsia was severe or appeared early. In the next pregnancy, low-dose aspirin from early on, first trimester risk screening and closer blood pressure monitoring are recommended.

Strict salt restriction has not been shown to prevent preeclampsia. A balanced diet with sensible salt intake is recommended, as throughout pregnancy.

CONTACT Call Us