Hypertensive disorders of pregnancy are a group of disorders that occur during pregnancy with elevated blood pressure, urinary protein, and often edema. Most of these manifestations occur during pregnancy and disappear after delivery, but some patients have hypertension before pregnancy, further increase in blood pressure after pregnancy, and develop urinary protein, or have urinary protein before pregnancy and increase in urinary protein after pregnancy. The disease is very common during pregnancy and affects about one out of every 10 pregnant women. In addition, the disease seriously affects maternal health and has a great impact on the development of the fetus in the womb.
Who is at risk for this disease?
It is not possible to predict exactly which pregnant women will develop this disease after pregnancy, but the following groups have been found to be at risk: pregnant women who are pregnant for the first time, pregnant women who are too young (<18 years old), pregnant women who are too old (>35 years old), pregnant women with multiple pregnancies (e.g., twins, triplets, etc.), pregnant women who have had this disease in past pregnancies or whose mothers or sisters or other family members have had this disease in pregnancy, pregnant women with chronic hypertension, chronic nephritis, diabetes, obesity, malnutrition, and poverty. Pregnant women with chronic hypertension, chronic nephritis, diabetes, obesity, malnutrition, poverty and low social status are more likely to suffer from hypertensive disorders during pregnancy.
What are the manifestations of hypertensive disorders in pregnancy?
Hypertensive disorders during pregnancy include two types of cases: one is women who do not have hypertension before pregnancy and develop hypertension and proteinuria after 20 weeks of pregnancy; the other is women who have hypertension before pregnancy, that is, women who have chronic hypertension on top of pregnancy.
The first condition is characterized by an increase in blood pressure for the first time after 20 weeks of gestation, with a systolic blood pressure ≥ 140 mmHg or a diastolic blood pressure ≥ 90 mmHg, and in severe cases, proteinuria, which can range from “+” to “++++”, and pregnant women The degree of proteinuria can vary from “+” to “”, and pregnant women often have different degrees of edema. Patients feel dizziness, headache, blurred vision, nausea, loss of appetite, abdominal distention, and epigastric pain, etc. In severe cases, blindness, convulsions, coma, etc. can even cause the death of the mother and child. As the disease affects all organs of the body, especially the heart, brain, liver, kidneys and other important organs, there are often manifestations of insufficiency of these organs, such as elevated serum alanine aminotransferase, portal aminotransferase and lactate dehydrogenase; when the kidney function is impaired, serum creatinine, urea nitrogen and uric acid are elevated, and in severe cases, electrolyte disorders and acid-base imbalance may occur.
In the case of chronic hypertension before pregnancy, most of the cases are aggravated during pregnancy, with further increase in blood pressure and proteinuria or increased urine protein, and with the development of the disease, all the above-mentioned manifestations can occur.
Why does hypertensive disorders in pregnancy have these manifestations?
Why is hypertensive disorders during pregnancy so serious and harmful to so many organs of the body? In fact, the essential change of this disease is the spasm of small blood vessels throughout the body of the pregnant woman and the decrease of blood flow to all organs of the system, which causes a series of damages caused by ischemia and hypoxia to all organs of the body. Let’s analyze the changes of the main organs.
Brain: Due to the spasm of small blood vessels throughout the body, the blood vessels in the brain also spasm, and the permeability of small blood vessels in the brain increases, resulting in cerebral edema, congestion, ischemia, thrombosis and hemorrhage. Because of these changes in the brain, it is not difficult to understand why patients experience the aforementioned symptoms of dizziness, headache, blurred vision, convulsions and coma.
Kidney: Due to vasospasm, renal blood flow is reduced, resulting in glomerular and tubular damage, hence proteinuria, elevated uric acid and creatinine, and in severe cases, oliguria and renal failure.
Liver: Due to the systemic small blood vessel spasm, the liver is not supplied with enough blood and oxygen, so the liver is damaged and liver function abnormalities occur.
Cardiovascular: Due to the spasm of small blood vessels throughout the body, the peripheral resistance increases, therefore, the blood pressure increases, the compensatory contraction of the heart muscle increases the burden on the heart, and in severe cases, cardiac insufficiency and even heart failure occur.
Gastrointestinal tract: Due to smooth muscle edema and poor peristaltic function of the gastrointestinal tract, coupled with a large amount of ascites, patients often experience nausea, loss of appetite and abdominal distension and other discomforts.
Uteroplacental blood perfusion: Due to the spasm of small blood vessels throughout the body, the small spiral arteries of the uterus also spasm, making the placenta insufficient blood and oxygen supply, so the placental function decreases, the intrauterine fetus grows slowly, or even growth arrest, fetal distress and fetal death in the uterus.
How to treat hypertensive disorders in pregnancy?
There is no good treatment for hypertensive disorders in pregnancy so far, and all treatment is symptomatic. The aim of treatment is to prolong the gestational weeks as long as possible while keeping the mother safe so that the fetus can survive after birth. Therefore, if the onset of the disease is late and close to the full term of pregnancy, the treatment is relatively simple. If the condition does not improve after symptomatic treatment or is worse, termination of pregnancy is the best treatment method. However, for pregnant women with early onset of hypertension, treatment is more difficult. Although termination of pregnancy is the best treatment for this disease, the fetus cannot survive after birth or has serious preterm complications because the gestational age is too small at this time. Therefore, the treatment of such early-onset pregnant women should take into account both the health of the mother and the fetus.
In general, there are the following methods.
1. Pay attention to rest.
Ensure sufficient sleep, usually in left-sided position, and ensure not less than 10 hours of sleep per day. Left side
lying position can reduce the compression of the uterus on the abdominal aorta and inferior vena cava, so that the return blood volume increases and improve the blood supply to the uteroplacenta.
2.Sedation.
Sedation can be given to those with mental tension, anxiety or poor sleep. Appropriate sedation can eliminate the patient’s anxiety and mental tension, to lower blood pressure, relieve symptoms and prevent convulsions. Choose drugs that have less effect on the fetus and newborn, such as diazepam.
3.Antispasmodic treatment.
For more severe cases, antispasmodic treatment can be used. General antispasmodic treatment should be used for: ① control eclampsia convulsions and prevent further convulsions; ② when severe pre-eclampsia patients with severe headache, blurred vision, in order to prevent its development into eclampsia convulsions can use antispasmodic treatment; ③ severe pre-eclampsia patients used before delivery to prevent convulsions.
Antispasmodic drugs preferred magnesium sulfate, but magnesium sulfate if the use of excessive will occur toxic reaction, the first manifestation of the knee tendon reflex is weakened or disappeared, followed by general hypotonia, dyspnea, diplopia, slurred speech, serious respiratory muscle paralysis, and even respiratory arrest, cardiac arrest, life-threatening. Therefore, in the process of using magnesium sulfate, should promptly check whether the knee tendon reflex is weakened or disappeared, breathing should not be less than 16 times / min, urine volume of not less than 25ml per hour or not less than 600ml per 24h.
4, antihypertensive treatment.
The purpose of blood pressure lowering is to prolong the gestational weeks or improve the perinatal outcome. For those with blood pressure ≥ 160/110mmHg, or diastolic blood pressure ≥ 110mmHg, as well as those who had hypertension before the gestational period and have been treated with antihypertensive drugs, antihypertensive drugs must be applied. The recommended antihypertensive drugs are labetalol, nitroprusside, nicardipine and others. Sodium nitroprusside is effective in lowering blood pressure, but its metabolite (cyanide) has toxic effects on the fetus and should not be used before delivery. After delivery, if the blood pressure is too high, the application of other antihypertensive drugs is not effective, the party to consider using.
5.Diuretic therapy.
Generally not advocated, only used for systemic edema, acute heart failure and pulmonary edema.
6, timely termination of pregnancy.
As mentioned above, the treatment of the disease is only symptomatic. When the condition is severe, symptomatic treatment is not effective and the life of the mother and fetus may be endangered at any time, termination of pregnancy should be considered, or in patients who are close to full term and the fetus can survive after birth, the pregnancy should also be terminated. Is it more appropriate to terminate the pregnancy by vaginal delivery or by cesarean delivery? Generally speaking, the disease is not an indication for cesarean delivery, but for those with small gestational age and immature cervix, or those with obvious headache, blurred vision, nausea, vomiting and other aggravations during vaginal trial of labor, or those who fail to induce labor after labor induction, or those with obvious placental hypoplasia, or those with obstetric indications for cesarean delivery, the pregnancy should be terminated by cesarean delivery.
7. Close monitoring of maternal and child status during pregnancy.
Many methods of treatment for the disease have been described earlier, but the condition of the mother and child should be closely monitored during all the above treatments. Pregnant women should be asked if they are experiencing symptoms such as dizziness, changes in vision, upper abdominal discomfort, etc. They should also have their weight and blood pressure measured daily, and their urine protein and liver and kidney functions checked regularly to assess the extent of their condition. While monitoring the mother, the fetal development and placental function should be monitored regularly, which can be done by ultrasound, electronic fetal heart monitoring and fetal ECG.
Is there a way to predict hypertensive disorders of pregnancy?
There is no valid and reliable prediction method. The following methods have some predictive value and should be performed in the middle of pregnancy. Those with a positive prediction should be followed closely.
1. Mean arterial pressure (MAP) measurement.
MAP = (systolic pressure + diastolic pressure × 2)/3. When MAP ≥ 85 mmHg, there is a tendency for the disease to occur.
2.Turning test.
The blood pressure of pregnant women is measured in the left lateral position, and then the blood pressure is measured again after 5 minutes of turning over in the supine position, if the diastolic blood pressure in the supine position is ≥20mmHg compared with the diastolic blood pressure in the left lateral position, there is a tendency of the disease.
3.Uric acid measurement.
Serum uric acid > 5.9mg/L at 24 weeks gestation has a tendency to occur.
4.Blood rheology test.
When hematocrit ≥ 0.35, whole blood viscosity > 3.6 and plasma viscosity > 1.6, it indicates a tendency to develop pre-eclampsia.
Can hypertensive disorders during pregnancy be prevented?
Although its occurrence cannot be completely prevented, if the following points are achieved, the onset of the disease can be delayed or alleviated, so that the fetus can grow in utero for as long as possible and the survival rate of the newborn can be effectively improved.
1.Strengthen health education.
Make pregnant women understand the importance of regular checkups during pregnancy. Given that the incidence of the disease is higher among poor and backward people with low socio-economic status, part of the reason is related to the fact that such people do not do regular pregnancy health care or even never have pregnancy checkups during pregnancy. If regular perinatal health care is performed, and the doctor gives proper guidance when signs of the disease appear, the onset of the disease will be delayed to a certain extent or the disease will not develop too fast.
2.Guide pregnant women to have a reasonable diet and rest.
Pregnant women should eat food containing protein, vitamins, iron, calcium, zinc, selenium and other trace elements and fresh vegetables and fruits, reduce the intake of animal fat and over-salty food, but do not restrict salt and fluid intake; keep enough rest and a happy mood, and take more left-sided position to increase the blood supply to the placenta.
3, appropriate calcium supplementation.
For those who have high risk factors for hypertensive disease during pregnancy, appropriate calcium supplementation can prevent its occurrence and development. Domestic and international studies have shown that 1-2g of calcium supplementation daily can effectively reduce the occurrence of hypertensive disorders during pregnancy.
What is HELLP syndrome?
HELLP syndrome is a serious complication of hypertensive disorders in pregnancy, characterized by intravascular hemolysis, elevated liver enzymes and thrombocytopenia, which is a critical condition with serious effects on both mother and fetus, often endangering the life of mother and child. The clinical manifestations of the disease are similar to those of severe gestational hypertensive disorders. The key to diagnosis is to be on high alert for patients with gestational hypertensive disorders with right upper abdominal or epigastric pain, nausea and vomiting, and a clear diagnosis is needed through laboratory tests.
Intravascular hemolysis: patients with hemoglobin 60-90 g/L and broken red blood cells, spherical red blood cells, etc. seen in peripheral blood smears.
Elevated bilirubin in the serum.
Elevated liver enzymes: alanine aminotransferase, portal aminotransferase, and lactate dehydrogenase are elevated in the serum, with lactate dehydrogenase elevation appearing earliest.
Thrombocytopenia: platelet count <100x109/L.