What Causes Low Blood Pressure in Pregnancy?

Pregnancy hypertension (referred to as pregnancy-induced hypertension) is a unique and common disease of pregnant women. It is characterized by hypertension, edema, proteinuria, convulsions, coma, heart and kidney failure, and even mother and child death. Pregnancy hypertension syndrome is divided into mild, moderate and severe according to the severity. Severe pregnancy hypertension syndrome is also known as preeclampsia and eclampsia, which means convulsions based on hypertension.

Hypertension during pregnancy

Hypertension during pregnancy refers to the symptoms of hypertension, edema, proteinuria and other symptoms that appear transiently after 20 weeks of pregnancy and disappear after delivery. It is a pregnancy-specific disease and is one of the main causes of illness and death of pregnant women and perinatal infants. In late pregnancy, systolic blood pressure is above 140 mm Hg (18.7 kPa) and diastolic blood pressure is above 90 mm Hg (12.0 kPa). Hypertension must be considered. There are many theories of the cause of pregnancy-induced hypertension. Generally, it is believed that a certain substance from the placenta enters the mother's blood, causing the pregnant woman's body to change immune factors, leading to systemic arterial spasm in pregnant women and causing hypertension. Some studies have also found that it is related to genetic factors. Main clinical manifestations

Hypertension: The diagnosis can be made when the blood pressure reaches 140/90 mm Hg twice. Proteinuria: Mid-section urine should be taken for examination. Where the quantitative amount of urinary protein in 24 hours is greater than 0.5 grams, it is abnormal. Have both hypertension and urinary protein as preeclampsia. Edema. Symptoms: whether there are headaches, dazzling, chest tightness, nausea and vomiting. The emergence of these conscious symptoms indicates that the development of the disease has entered the pre-eclampsia stage, and corresponding inspection and treatment should be done in time. Convulsions and coma: Convulsions and coma are manifestations of the development of the disease to a severe stage. You should seek medical treatment immediately and terminate your pregnancy in a timely manner. ^[1]

First-time pregnant women, especially those younger than 20 years old or older than 40 years old; pregnant women with twins and multiple babies; women with susceptibility to hypertension and genetic factors; women with vascular disease, kidney disease, and abnormal glucose and lipid metabolism; Overweight or malnourished women. In addition, a history of severe preeclampsia, unexplained intrauterine or placental disorders, fetal growth restriction, and women with antiphospholipid syndrome who are pregnant again are also at high risk. In short, women in any of these situations should consult an obstetrician as early as possible before pregnancy.

In the second and third trimester of pregnancy, in addition to observing fetal movements, pregnant women should also pay attention to their weight gain, which should not exceed 0.5 kg per week. After 8 months of pregnancy, there may be mild edema in the feet every afternoon and disappear after rest. If the edema appears too early (such as pregnancy in June or July), lasts for a long time, does not disappear after rest, and the edema worsens and extends to the lower leg, you should immediately go to the hospital to check blood pressure and urine routine to know if there is high pregnancy blood pressure.

When lower limb edema occurs, blood pressure and urine routine are normal, the following issues should be paid attention to: Increase the number of birth examinations and go to the hospital for birth examinations once a week. Rest: Properly reduce workload and ensure adequate sleep. You can rest at home and be hospitalized if necessary. Left-side lying position: take the left-side lying position during rest and sleep. The left lying position can reduce the pressure of the right-handed uterus on the abdominal aorta and inferior vena cava, increase the blood volume of the heart, improve the renal blood flow, increase the urine volume, and help maintain normal uterine placental blood circulation. diet: should pay attention to intake of sufficient protein, vitamins, supplement iron and calcium. Pay attention to the above aspects, the condition can be alleviated, but there are a few cases, the condition continues to develop. Severe hypertension with proteinuria is called preeclampsia and requires hospitalization to end pregnancy in a timely manner. ^[1]

1. Perform regular checks in early pregnancy, mainly measuring blood pressure, urine protein, and weight. In particular, blood pressure is measured and edema observed at 20-32 weeks. Early mild mild hypertension during pregnancy can be cured or controlled by active and effective treatment.

2. Pregnant women and lactating women need to be very cautious when using antihypertensive drugs. Do not use them casually. Because some antihypertensive drugs can enter the fetus through the placenta or appear in breast milk, and have toxic and side effects on the fetus or infant. Some of the so-called proprietary Chinese medicines actually contain a certain amount of western medicine ingredients that are unfavorable to the fetus, and the traditional Chinese medicine itself is not without side effects. Pregnant women who use proprietary Chinese medicines and herbal medicines should also pay attention to this.

3. Pay attention to rest and nutrition. You must feel comfortable and relaxed, and strive to stay in bed for more than 10 hours a day, preferably in a lateral position, to improve blood circulation and improve kidney blood supply conditions. Don't eat too salty foods to ensure protein and vitamin intake. Avoid strong light, noise or vibration to prevent convulsions;

4. Correct the abnormal situation in time. If anemia is found, iron should be added in time; if swelling of the lower limbs is found, bed time should be increased and the feet should be raised to rest; when the blood pressure is too high, medication should be taken on time. The pregnancy should be terminated if the pregnancy is near full term or if the condition has not progressed severely during menstrual treatment.

5. Pay attention to past history. Pregnant women who have suffered from diseases such as nephritis, hypertension, and previous pregnancy with pregnancy-induced hypertension syndrome should be monitored under the guidance of a doctor.

Reduce animal fat intake Pregnant mothers with pregnancy-induced hypertension should reduce animal fat intake. Vegetable cooking is best based on vegetable oils, 20-25 grams per day. The heating energy of saturated fatty acids (such as lard, tallow, coconut oil, palm oil, etc.) should be less than 10%.
Controlling total food intake Excessive thermal energy intake during late pregnancy and excessive weekly weight gain are risk factors for pregnancy-induced hypertension. Therefore, pregnant women's intake of heat energy should be appropriate to gain 500 grams of weight per week. For pregnant women who are already obese, it is advisable to gain 250 grams per week.
Controlling sodium salt intake Sodium salt plays an important role in the prevention and treatment of hypertension. If you eat too much sodium every day, it will cause blood vessels to constrict and increase blood pressure. Therefore, pregnant mothers with pregnancy-induced hypertension should be limited to 3 to 5 grams per day. At the same time, keep away from foods with high salt content, such as: sauces, pickled products, smoked dried products, pickles, pickles, canned products, fried foods, sausages, ham, etc. In addition, soy sauce should not be taken too much, 6 ml of soy sauce is equivalent to about 1 gram of salt. If you are accustomed to the salty taste of pregnant mothers, you can use low sodium salt instead of common salt to improve the taste of less salt cooking.
Protein supplementation. Pregnant women with severe PIH often have hypoproteinemia due to excessive protein loss in the urine. Therefore, timely intake of high-quality protein, such as milk, fish, shrimp, eggs, etc., to ensure the normal development of the fetus. Daily protein supplements can be up to 100 grams.
Supplementing calcium-rich foods not only helps the fetus to develop bones and gums, but also stabilizes or lowers blood pressure. Pregnant women with pregnancy-induced hypertension should eat more calcium-rich foods, such as dairy products, soy products, fish and shrimp, sesame, etc., and calcium supplements can also be added appropriately. For hypocalcemia, the daily calcium intake can reach 2000 mg.