Hypertension during pregnancy is a disease that seriously affects the health of mothers and children around the world.

The Pregnancy Hypertension Diseases Group of the Obstetrics and Gynecology Branch of the Chinese Medical Association issued in April 2020. The guide aims to provide basic clinical treatment standards based on the current research status and current understanding of the pregnancy hypertension diseases worldwide.

This article only interprets the main parts that have been adjusted and modified, and the other parts are still interpreted in order to better understand and apply the Chinese Guide published in the series.

1. How to read the guide

1. The regional and continuous changes in the guidelines cannot be ignored: the guidelines have continuous changes. In recent years, various countries and academic organizations have successively updated relevant guidelines. Although there are some consensus and consistency in the classification and diagnostic standards and treatment of hypertensive diseases during pregnancy, there are still differences.

The Pregnancy Hypertension Diseases Group of the Obstetrics and Gynecology Branch of the Chinese Medical Association, based on the latest research progress at home and abroad, combined with my country's national conditions and clinical practice experience, the members of the histology group and relevant experts, after repeated discussions and modifications, referring to different foreign guidelines, were finally formed.

It should be noted that the guidelines have limitations of the historical era, and with the in-depth understanding of disease research and understanding, the guidelines will continue to be updated; the guidelines have more specificity of regional conditions, and for different regions, different groups and different medical conditions, it is more necessary to adapt to local conditions.

When applying guidance to clinical practice, it is necessary to understand that the guidelines and their clinical guidance are non-specified. Guidelines are suitable for common and general common problems in clinical practice and cannot replace the doctor's comprehensive analysis, judgment and decision-making of specific situations in complex clinical situations.

2. How to view research evidence and recommendations commonly found in guidelines: What is more important about clinical guidelines is to propose clinical guidelines based on evidence-based evidence.

Clinical evidence and recommendation recommendations were also classified. Most guidelines make recommendations of different levels based on research evidence. However, how to view recommendations is also a problem that cannot be separated from the actual clinical situation. Although some high-level recommendations are derived from high-level research results, they are not entirely true.

Research evidence and recommendations in obstetric guidelines collide in time. Among the recommended recommendations for the treatment of hypertensive diseases in severe pregnancy released by the WHO in 2018, the recommendations for antihypertensive drugs for severe pregnancy and their use methods were slightly revised on the recommendations for prevention and treatment of preeclampsia-eclampsia issued in 2011.

In both guidelines, WHO uses quantitative systematic evaluation of evidence rating tools to evaluate and level stratify research evidence, and classify the levels of evidence quality into high, medium, low and very low.

In the 2018 WHO guidelines, it is still emphasized that antihypertensive drugs should be used for pregnant women with severe pregnancy hypertension. Although the evidence level is very low, it is strongly recommended;

It is still recommended that the selection of antihypertensive drugs should be better than other drugs. Prescription administration is mainly based on the application, cost and availability of the drug by the clinician. Although the evidence level is very low, it is a conditional recommendation, which emphasizes that users need to refer to notes and evidence summary in order to correctly understand the guidelines and clinical use.

2. Understand the pathogenic mechanism of preeclampsia-the multi-factor, multi-mechanism and multi-pathways of eclampsia

In this paper, the pathogenic mechanism of preeclampsia-eclampsia is more clearly proposed, and the pathogenic mechanism of multiple factors, multiple mechanisms, and multiple pathways are more clearly proposed. The pathophysiological changes include chronic uterine placental ischemia, immune intolerance, lipoprotein toxicity, genetic blotting, increased trophoblast apoptosis, and maternal overreacting inflammatory responses to tolerated trophoblasts, etc.

It is also clearly pointed out that the common clinical problem is that the disease has developed into a severe disease when it is discovered due to the failure to identify and detect it early.

The purpose of this is to emphasize the early detection and screening of risk factors, prevent and early warning, and make early diagnosis and early intervention. This is an important clinical measure to prevent and treat hypertensive diseases during pregnancy.

3. Diagnostic classification of hypertensive diseases during pregnancy

Acute attacks of hypertension and severe hypertension during severe pregnancy

In the 2019 guidelines of the American Society of Obstetricians and Gynecologists, the criteria not found in the ACOG 2013 guidelines were added to the diagnosis of hypertension during pregnancy, and systolic blood pressure ≥160mmHg and diastolic blood pressure ≥110mmHg are included in the guidelines as diagnostic criteria for hypertension during severe pregnancy.

Regarding this point, my country has clearly included the diagnosis of hypertension during severe pregnancy as early as the middle stage. It not only continues to emphasize that when systolic blood pressure ≥160mmHg and diastolic blood pressure ≥110mmHg, it is necessary to repeat the measurement several minutes apart to obtain a timely diagnosis;

It is also emphasized that if severe hypertension occurs acutely, it will be persistent severe hypertension when the duration is >15 minutes, which is also called hypertension acute. Pay attention to severe hypertension, which can also lead to adverse outcomes of mother and child, and active anti-hypertensive drugs are needed. Hypertension during pregnancy can develop into preeclampsia;

Whether mild or severe hypertension is combined with symptoms involved in other systems, it should be diagnosed as preeclampsia and treated in accordance with preeclampsia; severe pregnancy hypertension should also be treated in accordance with preeclampsia.

White coat hypertension and occult, transient or transient hypertension

1. Positioning of hypertension and concealment, transient or transient hypertension in white coat:

Regarding white coat hypertension, occult hypertension, transient hypertension or transient hypertension, the status is not consistent in the classifications of various countries. For example, in the Canadian Obstetrics and Gynecology Association's 2018 Guidelines, systolic blood pressure 140mmHg and diastolic blood pressure 90mmHg are used as the definition of hypertension, and white coat hypertension is excluded;

In Australia's guide, white coat hypertension was included in the category of pregnancy hypertension as early as 2008;

In the classification, diagnosis and international clinical management guidance recommendations of the International Society for Pregnancy Hypertension Research in 2018, the classification, diagnosis and international clinical management guidance of the International Society for Pregnancy Hypertension, the previous classification of chronic hypertension was changed, and the Australian guidelines added the category of white coat hypertension, and also added one item of occult hypertension. Among the hypertension that occurs after 20 weeks of pregnancy, in addition to pregnancy hypertension and preeclampsia, transient hypertension was also added.

In the ISSHP category, you can see both one side of following the Australian guide and another aspect of it.

However, in the 2009 guideline in the United States, in addition to adding severe standards to the diagnosis of hypertension during pregnancy, there is neither white coat hypertension nor hidden, transient or transient hypertension classification in the diagnosis of hypertension. In fact, American scholars have always warned to pay more attention to relative hypertension.

2. The essential connotation of white coat hypertension and concealment, transient or transient hypertension: What is white coat hypertension? What is hidden, transient or transient hypertension?

It is not difficult to understand hypertension. On the one hand, there are two numerical standards of 140 and 90mmHg, and on the other hand, there are retest requirements for 4 hours or more intervals. From the current definition of hypertension, it can be seen that it can be diagnosed by meeting this standard.

Hypertension can occur in any place and occasion, or it can also show intermittentness rather than persistence; hypertension can vary from high or low to different degrees, and will also cause different forms of manifestations due to the individual cause and course of the disease, degree of condition and organ damage.

Therefore, white coat hypertension and occult, transient or transient hypertension are within the numerical range of hypertension, but dynamic monitoring is more needed.

Only through dynamic monitoring can we understand and discover the patient's real blood pressure changes, and provide corresponding response decisions, monitoring and treatment measures. Compared with SOGC's theory of excluding white coat hypertension, it is better to say that Australia has consistently alert to white coat hypertension.

With such a perspective and alertness, it can be found that occult hypertension will also have a dynamic excavation of transient hypertension. The human blood pressure changes continuously, but there is also individual heterogeneity. Not only does the degree of hypertension vary, but also includes differences in the location and time of occurrence.

Unfortunately, because it is impossible to monitor continuously all the time, it is impossible to obtain the value of continuous blood pressure changes at any time. However, using dynamic monitoring for a certain period of time, it is possible to discover the true blood pressure changes of these so-called white coat hypertension and hidden, transient or transient hypertension, and find more information worth obtaining.

This will allow clinical practitioners to take different intervention measures and active complication prevention and monitoring methods from an active perspective, so that early warnings can be taken first and actions will be taken first.

We should pay attention to white coat hypertension and relative hypertension, and pay attention to the problems of blood pressure regulation and underlying pathological conditions in this type of pregnant women, which are the basic factors for the development of preeclampsia.

For the early stage of hypertension, it has been suggested that blood pressure is at the normal high limit, and there are also problems with blood pressure regulation, which is also a risk factor, especially the problem of the continued development of hypertension and whether potential hypertension can be discovered.

For any relative hypertension, pay attention to the increase in the blood pressure or the change in the blood pressure within the normal range. For example, 20% of patients with eclampsia only have relative hypertension. The so-called transient and transient hypertension has problems with the body's self-regulation and balance, the problem of the development of the disease, and the problem of whether clinical monitoring is in place.

Regarding occult hypertension, occult means "seemingly normal" but with high blood pressure, the key is whether it can be discovered in time. Because hypertension is a conclusion on continuous variables based on instantaneous measurements, whether changes in blood pressure can be discovered in time is fundamental. Whether occulters can be found in seemingly normal people need high alertness and deep exploration, and attention should be paid to dynamic monitoring of changes in blood pressure and checking basic pathological conditions and hidden diseases.

3. What is dynamic blood pressure monitoring: Some people simply understand dynamic blood pressure monitoring as using dynamic blood pressure monitoring instruments for monitoring, or believe that once dynamic blood pressure monitoring does not find any problems, no longer pay attention to the changes or fluctuations of pregnancy blood pressure during pregnancy. This fixed thinking mode is not advisable in blood pressure monitoring management.

Dynamic blood pressure monitoring can be performed using dynamic blood pressure monitors, or self-monitoring at home, and hospitalized patients can also be monitored regularly by doctors or nurses.

Using dynamic blood pressure monitors has medical resources or economic expenses and does not require continuous use. They can be used when white coat hypertension and concealment, transient or transient hypertension and early hypertension, or when the patient needs to be surveyed for blood pressure changes, or when the condition progresses, or when determining the effect of antihypertensive drugs, the necessary monitoring should be used as appropriate in hospitals with conditions.

Family self-blood pressure monitoring is economical, simple and practical. It teaches pregnant women how to use their own blood pressure instruments and adjusts the frequency of blood pressure monitoring as appropriate. It can be 4 times a day, early, midnight, evening, and before going to bed, or 1 to 3 times a day, and records it on a list.

Hospitalized patients need to understand the fluctuations in blood pressure. Mild hypertension can be tested 2 hours apart within 24 hours of admission. Severe hypertension needs to be tested several minutes apart. After the anti-hypertension reaches the target blood pressure, continuous monitoring at intervals of 0.5 hours or 1 hour is required, depending on the condition.

4. Handling measures:

There are various means to antihypertension, and drug treatment is only one aspect.

Adjustment of living habits, diet and environment factors, and drug treatment are all intervention methods under different blood pressure levels.

Antihypertensive drugs are not required for white coat hypertension and occult, transient or transient hypertension, as well as relative hypertension and pre-hypertension, but it is not allowed to be left.

To understand the overall changes in blood pressure, not only dynamic monitoring and evaluation are required, but also management is required. If the blood pressure is increased by 30/15mmHg compared with the basal blood pressure but is lower than 140/90mmHg, although it is not used as a basis for diagnosis, it requires close follow-up. Pay attention to the change in the amplitude of blood pressure increase, that is, the problem of relative hypertension;

Pay attention to the pre-hypertension period, whether it is called the normal high limit or the pre-hypertension period, or it may be included in the hypertension category by some countries.

For the above situations, not only should family blood pressure monitoring be recommended, but should people with conditions do 24-hour dynamic blood pressure measurement, but they should also pay attention to the adjustment of living habits, diet and environment factors. These are the primary intervention measures to consider. Give these pregnant women confidence, avoid various tensions, pay attention to proper rest and proper diet. These are intervention methods to prevent the blood pressure from transforming into adverse aspects.
Chapter completed!