Hypertensive disorders in pregnancy (HDP) are common clinical conditions during pregnancy. Blood pressure control is the main therapeutic goal for HDP and a key focus of clinical management.

There are numerous types of antihypertensive drugs with diverse mechanisms of action, and the particularity of the perinatal period leads to many uncertainties in clinical drug selection. To this end, the Chinese Medical Association, together with multidisciplinary experts, has put forward evidence-based recommendations targeting key and hot clinical issues and formulated this guideline. It aims to standardize clinical management and provide a standardized plan for reducing maternal and infant risks of perinatal hypertension.

1-1 First-line antihypertensive drugs: Labetalol, nifedipine, and methyldopa are recommended as first-line antihypertensive drugs. (1B)

1-2 ACEI or ARB drugs: Hypertensive women taking ACEIs, ARBs, or non-peptide renin inhibitors should discontinue these drugs during preconception, switch to first-line antihypertensive drugs for pregnancy, and plan pregnancy after blood pressure stabilizes. For unplanned pregnancy, ACEIs or ARBs are not absolute indications for termination of pregnancy. (1B)

1-3 Individualized regimen: For hypertensive patients with inadequate response to first-line antihypertensive drugs or complicated with organ function damage, joint evaluation by cardiologists and obstetricians is recommended to determine an individualized antihypertensive drug regimen and timing of pregnancy. (GPS)

Labetalol, nifedipine, and methyldopa are the preferred antihypertensive drugs during preconception. A multicenter randomized controlled trial on medication during pregnancy published in The Lancet in 2019 randomly assigned 894 pregnant women to nifedipine, labetalol, and methyldopa treatment groups, with no statistically significant differences between groups.

Multiple studies have shown that the use of ACEIs (e.g., enalapril, captopril) and ARBs (e.g., losartan, valsartan) during pregnancy, especially in the second and third trimesters, may lead to fetal renal hypoplasia, oligohydramnios, and other malformations. Therefore, it is recommended to switch to drugs relatively safe for offspring during preconception.

A systematic review including 14 studies analyzed 6,234 pregnant women exposed to ACEIs or ARBs in the first trimester, 4,104 pregnant women exposed to other oral antihypertensive drugs (e.g., methyldopa, β-blockers, or calcium channel blockers) in the first trimester, and 1,872,733 pregnant women with no exposure to any antihypertensive drugs in the first trimester. The results showed that offspring exposed to ACEIs or ARBs in the first trimester had a higher risk of severe congenital malformations, cardiovascular abnormalities, and stillbirth.

Non-peptide renin inhibitors (e.g., aliskiren) are fetotoxic and should be avoided. Long-term use (≥60 days) of certain β-blockers (e.g., atenolol) may be associated with fetal growth restriction and requires caution. Diuretics (e.g., hydrochlorothiazide) may cause hypovolemia, affect placental perfusion, and thus lead to fetal growth restriction and electrolyte disorders, so they should also be used cautiously during preconception.

Women taking oral antihypertensive drugs should gradually reduce the dosage and discontinue contraindicated drugs under the guidance of doctors, introduce safe alternative drugs, make a smooth transition, and maintain stable blood pressure. Contraception is recommended during drug conversion. If menstruation is delayed, pregnancy should be confirmed in a timely manner and drugs safe for pregnancy should be switched immediately. Accidental exposure to ACEIs or ARBs in the first trimester is usually not an indication for termination of pregnancy, but continued pregnancy and observation should be carried out with the patient's full informed consent.

2-1 Antihypertensive indication: A systolic blood pressure ≥140mmHg or diastolic blood pressure ≥90mmHg is recommended as the indication for perinatal antihypertensive treatment. (1B)

2-2 Antihypertensive target: It is recommended that the target blood pressure during perinatal period be controlled below 135/85mmHg, but not lower than 110/70mmHg. (2C)

An international randomized clinical trial published in the New England Journal of Medicine in 2015 included 987 pregnant women with gestational hypertension. Comparison based on blood pressure control showed that strict control (maintaining diastolic blood pressure at 85mmHg) could reduce the incidence of severe maternal hypertension, with no significant difference in fetal outcomes.

An international multicenter randomized controlled study in 2022 included 2,408 pregnant women with chronic hypertension. The active antihypertensive group started treatment when blood pressure ≥140/90mmHg, and the traditional antihypertensive group started treatment when blood pressure ≥160/110mmHg. The incidence of severe adverse outcomes (progression to preeclampsia, preterm birth <35 weeks due to maternal or fetal diseases, placental abruption) was followed up. The active antihypertensive group was 30.2%, which was lower than 37% in the traditional antihypertensive group.

A meta-analysis in 2023 included 12 randomized controlled trials and 4,461 pregnant women with mild to moderate hypertension (2,395 in the intervention group and 2,066 in the control group). The results found that antihypertensive treatment was associated with a reduced incidence of 7 adverse outcomes, including severe hypertension, preeclampsia, placental abruption, electrocardiographic changes, renal impairment, pulmonary edema, and neonatal mortality. There were no statistically significant differences in other neonatal outcomes (such as fetal growth restriction, fetal death, low birth weight infants, admission to neonatal intensive care unit, etc.) between the two groups. These results support the beneficial effects of pharmacotherapy for mild hypertension on maternal and neonatal outcomes without significant adverse fetal events.

Another multicenter randomized controlled trial on postpartum non-severe hypertension in 2024 showed that compared with the control group, the treatment group had better blood pressure control (56.7% vs. 51.5%), indicating that antihypertensive treatment for mild chronic hypertension during pregnancy helps control postpartum blood pressure below 140/90mmHg.

Based on the analysis of multiple guidelines and studies, a systolic blood pressure ≥140mmHg or diastolic blood pressure ≥90mmHg is recommended as the indication for initiating antihypertensive treatment during perinatal period. The blood pressure should be controlled below 135/85mmHg, but not lower than 110/70mmHg as the target blood pressure to ensure uterine-placental blood perfusion.

3-1 Second-line antihypertensive drugs: Amlodipine, diltiazem, and other second-line antihypertensive drugs may be considered when first-line drugs have inadequate antihypertensive effects during pregnancy. (2B)

3-2 Alternative regimens: For inadequate response to antihypertensive drugs during pregnancy, 24-hour ambulatory blood pressure monitoring is recommended. If conditions permit, hemodynamic typing should be performed to guide the use of antihypertensive drugs; for severe or malignant hypertension, multidisciplinary team consultation should be conducted as soon as possible to identify the cause of hypertension, adjust the antihypertensive drug regimen, determine the appropriate antihypertensive target, and assess whether pregnancy can continue. (1C)

A meta-analysis in 2022 included 17 randomized controlled trials and found that amlodipine could better control systolic and diastolic blood pressure. There were no statistically significant differences in pregnancy outcomes such as cesarean section, preterm birth, placental abruption, fetal growth restriction, fetal distress, and neonatal asphyxia compared with nifedipine, indicating that the therapeutic effect of amlodipine was slightly better than that of nifedipine. Another clinical observational study on pregnant women with chronic hypertension showed that exposure to amlodipine in the first trimester did not significantly increase the incidence of birth defects in offspring compared with other antihypertensive drug groups or the non-exposure group.

A network meta-analysis in 2024 included 8 randomized controlled trials and 1,192 patients with preeclampsia. The antihypertensive effect of diltiazem was superior to that of labetalol, nicardipine, methyldopa, and other drugs.

In a recent clinical study by Davis et al. including 1,120 pregnant women with hypertension, 653 and 467 received antihypertensive treatment based on hemodynamic typing and experience, respectively. The results found that the dosage of antihypertensive drugs required for treatment based on hemodynamic typing was significantly reduced, and the probability of needing drug replacement was also significantly lower. Therefore, selecting antihypertensive drugs during pregnancy based on hemodynamic typing may be the focus of management for severe HDP patients in the future.

24-hour ambulatory blood pressure monitoring provides comprehensive information on blood pressure in both work and life states, and can assess diurnal blood pressure patterns, blood pressure phenotypes, and short-term blood pressure variability. Antihypertensive treatment based on 24-hour ambulatory blood pressure monitoring can better control blood pressure and accurately guide the use of antihypertensive drugs.

4-1 Indication for emergency antihypertension: Emergency antihypertension is recommended when systolic blood pressure is persistently ≥160mmHg or diastolic blood pressure is persistently ≥110mmHg during pregnancy, and blood pressure should be reduced to a safe range as soon as possible. (2C)

4-2 Emergency antihypertensive drugs: For patients not taking any antihypertensive drugs, oral nifedipine tablets or other available equivalent drugs (labetalol, nitrendipine, etc.) are preferred. The dosage can be repeated after 10-20 minutes according to the blood pressure reduction. If the effect is still unsatisfactory after 3 consecutive repeated doses, it is recommended to switch to an intravenous antihypertensive regimen. (1B)

4-3 Emergency antihypertensive regimen: Oral drugs are preferred. If oral antihypertensive drugs are ineffective or emergency antihypertension is required due to severe complications, intravenous injection of labetalol, urapidil, nicardipine, nitroglycerin, phentolamine, and other drugs safe for the fetus is recommended for antihypertension. (2C)

Severe hypertension during pregnancy is diagnosed when systolic blood pressure ≥160mmHg and/or diastolic blood pressure ≥110mmHg. If blood pressure suddenly rises above 160/110mmHg and lasts for more than 15 minutes, it is persistent severe hypertension, also known as hypertensive emergency. Most guidelines at home and abroad use 160/110mmHg as the antihypertensive threshold.

A systematic review in 2023 showed that for pregnant women with severe hypertension, oral nifedipine achieved the target blood pressure faster than intravenous labetalol, and the nifedipine group required a lower dose to reach the target blood pressure, with no increase in maternal and neonatal complications. Therefore, for emergency antihypertension, nifedipine is the first choice for patients who have not used antihypertensive drugs.

In emergency antihypertension, if oral antihypertensive effect is poor, intravenous drugs are often needed. Labetalol is suitable for blood pressure control during pregnancy and puerperium, especially for situations requiring rapid blood pressure reduction. Intravenous labetalol takes effect quickly (within 5 minutes) and has α and β receptor blocking effects. Women with a history of myocardial disease, cardiac decompensation, cardiac conduction block, asthma, and bradycardia should avoid using it to prevent inducing underlying diseases.

Nicardipine is a commonly used calcium channel blocker in clinical practice. A randomized controlled trial of severe hypertension during pregnancy showed that both intravenous nicardipine and urapidil achieved effective blood pressure control targets. The incidence of maternal discomfort such as headache, nausea, and vomiting in the urapidil group was lower than that in the nicardipine group. Another randomized controlled study of severe hypertension comparing intravenous labetalol and nicardipine found that the nicardipine group achieved the blood pressure control target faster with a lower incidence of respiratory distress syndrome, but neonatal hypoglycemia was more likely to occur.

For patients with contraindications to labetalol or nicardipine or unable to obtain these drugs, nitroglycerin and phentolamine can be used alone or in combination to achieve emergency antihypertension. Nitroglycerin can dilate blood vessels, and its side effects include headache, tachycardia, and methemoglobinemia. Nitroglycerin is contraindicated in patients with hypertensive encephalopathy. The combined use of nitroglycerin and phentolamine can alleviate adverse reactions such as headache to a certain extent.

If blood pressure is still not up to standard 6 hours after the combination of two drugs, it is recommended to transfer to the intensive care unit; for undelivered patients, termination of pregnancy needs to be considered, and intravenous sodium nitroprusside can be selected if necessary, with the prenatal application time not exceeding 4 hours. For example, in the following situations: (1) Severe hypertension unresponsive to other antihypertensive drugs; (2) Pregnant women with clinical manifestations of hypertensive crisis; (3) Pregnant women with severe complications (such as acute heart failure, pulmonary edema, intracranial hemorrhage, etc.) requiring emergency antihypertension. Prenatal application for more than 4 hours poses a risk of fetal cyanide poisoning.

5-1 Monitoring indicators: It is recommended to monitor vital signs, blood routine, liver and kidney function, myocardial enzymes, urinary protein, and assess fetal status during antihypertensive treatment to identify organ function damage, hemolysis, elevated liver enzymes, and low platelets (HELLP syndrome) and fetal hypoxia as early as possible. (2C)

5-2 Monitoring of severe complications: Pregnant women are advised to conduct immediate condition assessment when clinical symptoms such as decreased fetal movement, dyspnea, headache, dizziness, altered consciousness, chest and back pain, visual changes, and abdominal pain occur to detect disease progression and severe complications early. (2C)

The occurrence and development of HDP are rapid. While standardizing antihypertension, it is necessary to strengthen the monitoring of mothers and fetuses and dynamically adjust the treatment plan to maximize the safety of mothers and fetuses.

A retrospective study in 2023 showed that standardized blood pressure monitoring can effectively predict severe preeclampsia. A retrospective study in 2024 showed that hemoglobin, liver and kidney function, coagulation function, myocardial enzymes, and D-dimer are effective biochemical indicators for evaluating and predicting preeclampsia complicated with HELLP syndrome.

During antihypertensive treatment for HDP, pulmonary embolism and heart failure should be vigilant. Their common clinical manifestations are shortness of breath, tachycardia, chest pain, and lower limb pain and swelling. Acute heart failure, one of the complications of HDP, is characterized by progressive dyspnea, chest discomfort, cough, orthopnea, wheezing, and paroxysmal nocturnal dyspnea. HDP is a risk factor for pregnancy-related stroke, with headache as the initial symptom, mostly severe headache, which may be accompanied by neurological changes such as confusion and disturbance of consciousness, and symptoms of increased intracranial pressure such as vomiting and seizures. Placental abruption, one of the severe complications of HDP, is mostly clinically manifested by abdominal pain, vaginal bleeding, and abnormalities in fetal heart rate and fetal movement.

Preeclampsia patients are often complicated with placental insufficiency, and chronic fetal distress is a common clinical phenomenon. Fetal movement is the most direct monitoring indicator of fetal status. Therefore, once preeclampsia patients experience tearing, stinging, or severe pain in the abdomen, chest, back, and other parts, severe complications such as placental abruption, aortic dissection, and HELLP syndrome with liver rupture should be highly vigilant, and differentiation from diseases such as acute myocardial infarction and pulmonary embolism should be noted.

6-1 Postpartum medication adjustment: It is recommended to adjust the type of medication according to the severity of target organ damage and whether breastfeeding is needed postpartum. (GPS)

6-2 Postpartum antihypertensive drugs: For postpartum patients with new-onset hypertension or poorly controlled blood pressure, calcium channel blockers (e.g., nifedipine, diltiazem, amlodipine) are recommended as the first choice; if monotherapy is ineffective, combination antihypertension with labetalol, methyldopa, or ACEIs (e.g., captopril, enalapril) is recommended; for patients with refractory hypertension or large blood pressure fluctuations, cardiologist consultation is recommended to guide the antihypertensive treatment plan. (1B)

6-3 Postpartum medication and breastfeeding: Maternal breastfeeding is not recommended for postpartum women taking ARBs. (GPS)

6-4 Postpartum depression and medication: Methyldopa is contraindicated in postpartum patients with depression or high risk of depression. (GPS)

Postpartum 7-10 days is the peak period of blood pressure fluctuation and a high-risk period for cerebrovascular accidents. Therefore, continuous blood pressure monitoring and antihypertensive treatment after delivery are important measures to prevent severe postpartum complications. However, factors such as postpartum breastfeeding and changes in postpartum drug metabolism should be considered, and antihypertensive drugs should be selected according to the degree of organ function damage and whether breastfeeding is performed. For patients with new-onset or poorly controlled blood pressure, it is necessary to replace antihypertensive drugs or adopt combination therapy.

Nifedipine used in the treatment of HDP can be continued as a first-line antihypertensive drug during lactation. For breastfeeding women after delivery, labetalol, nifedipine, enalapril, or captopril are recommended, and diltiazem and verapamil can also be selected.

A randomized controlled trial in 2023 observed the effect of oral labetalol or amlodipine on postpartum hypertension control. The results showed that the average time to achieve sustained blood pressure control in the amlodipine group was shorter than that in the labetalol group, and the number of severe hypertension episodes was less than that in the labetalol group. The concentrations of amlodipine and enalapril