Pregnant women with twin pregnancies are more likely to suffer from gestational hypertension. How to prevent it?

Author: Sun Yu, Chief Physician, Peking University First Hospital

Reviewer: Zou Liying, Chief Physician, Beijing Obstetrics and Gynecology Hospital, Capital Medical University

As we all know, twin pregnancy itself is a heavy burden on the mother, because after pregnancy, the mother's blood volume will increase significantly in order to supply the enlarged uterus, the placenta attached to the uterus, and the growth needs of the fetus.

The mother needs to bear this increased blood burden. If she is pregnant with twins, the pregnant mother's blood burden will definitely be heavier. Therefore, for the pregnant mother, she is prone to various complications.

For example, the incidence of gestational hypertension in pregnant women with multiple pregnancies is about 4 times higher than that in pregnant women with single pregnancies. Generally, the incidence of gestational hypertension in single pregnancies is about 5%, while the incidence of gestational hypertension in twin pregnancies is about 20%.

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1. Is the occurrence of gestational hypertension related to the placenta?

Hypertensive disorders complicating pregnancy are a very common and unique complication during pregnancy. So far, its pathogenesis has not been explored very clearly, but generally speaking, it is a disease related to the placenta. Because the placenta only exists during pregnancy, if the placenta is expelled from the body, that is, the delivery is over, hypertensive disorders complicating pregnancy will generally improve.

As for twin pregnancies, if they are dichorionic twins, there are two placentas, and if they are monochorionic twins, there is only one placenta. However, the development of this placenta is definitely different from that of a single pregnancy, so there will definitely be some problems with placental implantation, which may be related to gestational hypertension.

In addition, due to twin pregnancy, the pregnant mother's blood burden will be heavier, which makes her more susceptible to gestational hypertension. Because some manifestations of gestational hypertension, such as pulmonary edema and heart failure, are related to the blood burden.

2. What harm does hypertension during pregnancy do to the fetus?

The main impact of gestational hypertension on the fetus is that it affects the blood vessels of the placenta. If the blood vessels of the placenta are affected, the fetus will grow smaller, which we call fetal growth restriction. This is the most common impact of gestational hypertension on the fetus.

In addition, gestational hypertension can also easily lead to placental abruption. Because of high blood pressure, blood vessels will contract, especially when blood pressure fluctuates greatly, placental abruption is more likely to occur. Placental abruption is the separation of the placenta before the fetus is delivered, and the fetus relies on the placenta for blood supply, so the fetus will soon be in danger of life. This is also a relatively large impact on the fetus.

Another issue is premature birth. If the pregnancy-related hypertension is very severe, the pregnancy needs to be terminated immediately. This will cause iatrogenic premature birth and increase the overall complications, so the perinatal mortality rate will also increase relatively.

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3. To prevent gestational hypertension, what special attention should pregnant women with multiple pregnancies pay?

For twin pregnancies, to prevent gestational hypertension, one thing is to pay attention to the amount of water you drink. If edema occurs, you must limit your intake more strictly and don't drink too much water.

In addition, you should monitor your blood pressure. Generally speaking, during prenatal checkups, we may have a checkup every four weeks in the early pregnancy, every two weeks in the middle pregnancy, and once a week in the late pregnancy. However, when we do not have prenatal checkups, we should also monitor our blood pressure.

As for gestational hypertension, it has some other high-risk factors, such as obesity, so you need to control your weight; it is also related to malnutrition, so you need to have a balanced diet.

More importantly, we must detect the problem of high blood pressure early. If we can diagnose and treat it in time when the condition is not very serious, we can prevent the occurrence of serious complications.

4. Which pregnant women can take low-dose aspirin to prevent gestational hypertension?

At present, a relatively effective measure to prevent hypertension during pregnancy is to take a small dose of aspirin orally. Studies have now confirmed that if a small dose of aspirin is taken orally from the 12th week of pregnancy, it can prevent severe hypertension during pregnancy.

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However, we currently only recommend this preventive measure for high-risk groups, not that all pregnant mothers need to take it.

For example, pregnant women who are obese or malnourished are all high-risk groups. There are also people with a corresponding medical history or family history, such as having had gestational hypertension in the last pregnancy, or her mother or sister having had gestational hypertension during pregnancy.

In addition, if she has some chronic diseases, such as chronic hypertension, and had chronic hypertension problems before pregnancy, including chronic kidney disease, rheumatic autoimmune diseases such as lupus erythematosus, these are high-risk groups. They can take small doses of aspirin under the guidance of a doctor to prevent gestational hypertension.