How to Prevent Hypertension in Pregnancy

The importance of blood pressure as a mandatory part of every pregnancy checkup speaks volumes about its importance. Clinically common hypertensive disorders in pregnancy will pose a great risk to the health of mother and child if not well controlled, so let's take a closer look at blood pressure during pregnancy today.

1. Definition of blood pressure and physiological factors affecting blood pressure fluctuations.

Definition of blood pressure.

Blood pressure is the lateral pressure of the flowing blood for a unit area of the vessel wall. Generally refers to the upper arm brachial artery normal for systolic pressure of 90-140 mm Hg, diastolic pressure of 60-90 mm Hg, under normal circumstances a person's blood pressure in the two upper extremities can be different, a difference of 10-20 mm Hg.

Physiologic factors of blood pressure variation

Blood pressure is not constant and is subject to physiological changes due to multiple factors, such as exercise, sleep, environment, season, age, gender, and emotion.

• The pattern of blood pressure changes throughout the day: 6-10 am, 4-8 pm the highest, evening or night the lowest, a double peak and a valley fluctuation trend. 

• Age: generally speaking, the older you are, the higher your blood pressure is. 

• Blood pressure rises after exercise and meals, and returns to normal after rest. 

• Mood swings: such as tension, fear, anxiety, happiness, anger, etc. can cause a sudden rise in blood pressure.

• Environment and season: blood pressure is higher in cold areas and winter, and lower in warm places and summer.

• Different parts of the same person have different blood pressure, for example, the blood pressure of the left and right upper limbs, and the blood pressure of both upper and lower limbs can be different.

The main factors affecting blood pressure

• Blood volume and volume ratio, the greater the ratio, the higher the blood pressure.

• Heart rate: the faster the heart rate, the higher the blood pressure.

• The elasticity of the large arteries. If the elasticity of blood vessels decreases in the elderly, the systolic pressure increases.

• Diastolic blood pressure increases when peripheral resistance increases.

• Cardiac output: the higher the cardiac output, the higher the blood pressure, all other factors being equal.

2. Changes in blood pressure during pregnancy

Pregnancy is a special physiological period for women in their reproductive years, the body will make some adaptations and most of them can go through pregnancy smoothly, therefore, the blood pressure of most pregnant women is in the normal range, and very few of them may have hypotension or hypertension.

Hypotension is mainly caused by the early pregnancy reaction and the decrease of peripheral resistance in the middle of placental blood circulation.

Some pregnant women may have elevated blood pressure, which may develop into gestational hypertension and systemic small artery spasm causing ischemia and hypoxia of important organs, endangering the health of mother and child, such as placental abruption, pulmonary edema, gestational hypertensive heart disease, acute renal failure, postpartum hemorrhage, etc. It may also cause intrauterine growth retardation, stillbirth, stillbirth, placental hypofunction, placental insufficiency of blood supply, etc.

3. How to self-monitor blood pressure at home

For those who have previous history of hypertension, family history of hypertension, obesity, diabetes, etc., or those who need to observe hypertension at home for the first time should advocate self-monitoring blood pressure at home.

• Choose a regular manufacturer's upper arm cuff electronic sphygmomanometer, avoid using a desktop mercury sphygmomanometer, and prepare a record book and pen.

• Before measuring blood pressure, take 15 to 20 minutes of calm rest, and use the same sphygmomanometer at the same time every morning and evening to measure in the same area, with the height of the sphygmomanometer in line with the position of the heart, and take the average of each measurement 2-3 times and record it well, and bring it to the doctor at the time of consultation.

4. Understanding hypertensive disorders in pregnancy

Hypertensive disorders in pregnancy are a disease specific to pregnancy and are a series of conditions mainly related to increased blood pressure, including the following types.

gestational hypertension: 

a systolic blood pressure ≥ 140 mm Hg and/or a diastolic blood pressure ≥ 90 mm Hg at 20 weeks of gestation, with a return to normal blood pressure and negative urine protein at 12 weeks postpartum, confirms the diagnosis.

Pre-eclampsia.

• Mild preeclampsia: systolic blood pressure ≥ 140 mm Hg and/or diastolic blood pressure ≥ 90 mm Hg after 20 weeks of gestation, accompanied by 24-hour proteinuria greater than or greater than 0.3 g.

• Severe pre-eclampsia: systolic blood pressure ≥ 160 mm Hg and/or diastolic blood pressure ≥ 110 mm Hg during pregnancy, 24-hour proteinuria greater than or greater than 3.0 grams, or impaired liver and kidney function and other organs.

Eclampsia: 

It is the most dangerous stage of hypertensive disorders in pregnancy and is the sudden onset of convulsions on top of preeclampsia that cannot be explained by other causes.

Chronic hypertension in pregnancy: 

A patient who was hypertensive before pregnancy and whose blood pressure did not significantly worsen during pregnancy; or hypertension first diagnosed after 20 weeks of pregnancy and fails to return to normal after 12 weeks postpartum.

Chronic hypertension complicated by preeclampsia

Chronic hypertensive pregnant women with 24-hour urine protein greater than or equal to 0.3 grams or random proteinuria (+) after 20 weeks of pregnancy; or proteinuria before pregnancy and significant increase in urine protein after pregnancy, blood pressure continues to rise, and thrombocytopenia.

5. Prevention of hypertensive disorders during pregnancy

During pregnancy, the mother must pay attention to a reasonable mix of coarse and fine, meat and vegetable balanced nutrition, abstain from high salt foods, the daily intake of sodium is not more than 6 grams, and the daily intake of calcium in the middle and late pregnancy is 600-1200 mg.

Have enough sleep and suitable physical exercise. Pregnant mothers should get 10 hours of sleep a day, especially a 2-hour lunch break. Appropriate exercise can promote blood circulation, improve appetite and facilitate sleep. For example, walking for about 30 minutes a day is the best way for pregnant women not to feel fatigued, and it is also good to do some household chores that you can do.

In conclusion, it is especially important for pregnant women to learn about blood pressure and hypertensive disorders in pregnancy to prevent and detect hypertensive disorders in pregnancy. It is necessary to take some preventive measures in order to avoid the health damage caused by hypertensive disorders in pregnancy to mother and child.

If you need more information, you can also refer to the links below:

NIH.US

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CDC