In order to bring you the best possible user experience, this site uses Javascript. If you are seeing this message, it is likely that the Javascript option in your browser is disabled. For optimal viewing of this site, please ensure that Javascript is enabled for your browser.
Did you know that your browser is out of date? To get the best experience using our website we recommend that you upgrade to a newer version. Learn more.

Hypertension in pregnancy

Hypertension (HTN) is the most commonly encountered disorder during pregnancy. High blood pressure has a negative impact on the mother and the foetus, which is why early diagnosis and proper control are mandatory to avoid complications. There are many forms of HTN disorder during pregnancy. The threshold for initiation of antihypertensive medications differs for gestational and chronic HTN during pregnancy, being lower in gestational HTN. Pre-eclampsia/eclampsia syndrome is a severe form of gestational HTN, which is only curable by delivery of the foetus.  Management of HTN during pregnancy is challenging and it requires collaboration between obstetricians and cardiologists.


Introduction and prevalence

Hypertension (HTN) is a worldwide health problem that affects about 25-40% of individuals. It is a major cardiovascular risk factor and it is associated with many cardiovascular complications (e.g., stroke, heart failure). The prevalence of raised blood pressure is highest in Africa, where it is 46% for both sexes combined. HTN can affect people at any age; women at child-bearing age are no exception.

HTN is the most common medical disorder during pregnancy, with a prevalence of 5-10% of all pregnancies worldwide [1,2]. HTN and antihypertensive drugs have adverse effects on both the mother and the foetus.

Management of HTN during pregnancy needs expertise in the field of high-risk pregnancy and cardiovascular diseases, which is why a combined team of obstetricians and cardiologists is an important prerequisite.

Definition and forms of HTN disorders in pregnancy

Diagnosis of HTN during pregnancy is based on the standard office blood pressure (BP) measurements. Although ambulatory blood pressure monitoring (ABPM) is more accurate in diagnosing HTN and is better in predicting outcomes [3], it cannot be routinely applied because of time and money constraints. The use of automated BP measuring devices is not recommended because they tend to under-record BP and they are unreliable in pre-eclampsia [2].

Hypertension disorders in pregnancy (HDP) are classified into mild HTN (systolic BP 140-159 mmHg and/or diastolic BP 90-109 mmHg) or severe HTN (BP ≥160/110 mmHg) [1].

The nomenclature of the different forms of HDP depends on the timing of the first diagnosis of HTN and the persistence of high BP after delivery. The following forms are described in the recent European guidelines [1]:

  • Pre-existing hypertension

HTN diagnosis before pregnancy, early in pregnancy (before 20 weeks of gestation), or HTN continues after six weeks post-partum.

  • Gestational hypertension

HTN first diagnosis during pregnancy, after 20 weeks of gestation; it usually resolves within six weeks post-partum. Gestational HTN is considered a form of secondary HTN [1].

  • Pre-existing hypertension plus superimposed gestational hypertension with proteinuria
  • Pre-eclampsia (vide infra)
  • Antenatally unclassifiable hypertension

This term is used when HTN is first diagnosed after 20 weeks of gestation and it is unclear if hypertension was pre-existing. Reassessment six weeks post-partum will help distinguish pre-existing from gestational hypertension.


In addition to the well-known risks of HTN, maternal risks include placental abruption and disseminated intravascular coagulation.

The foetus is at high risk of intrauterine growth retardation (25% of cases of pre-eclampsia), prematurity (27% of cases of pre-eclampsia), and intrauterine death (4% of cases of pre-eclampsia) [2].

The long-term risks of HDP and pre-eclampsia include a fourfold higher risk of chronic HTN and a twofold higher risk of stroke and ischaemic heart diseases [4].

Women who develop severe hypertension have higher rates of adverse maternal (pre-eclampsia, HELLP syndrome [haemolysis, elevated liver enzymes, and a low platelet count], and maternal length of hospital stay ≥10 days) and perinatal outcomes (perinatal death, high-level neonatal care for >48 hrs, birth weight <10th percentile, pre-eclampsia, and pre-term delivery) [5].


Basic laboratory workup includes haemoglobin and haematocrit, urinalysis, liver enzymes, serum creatinine, and serum uric acid [1]. Hyperuricaemia in HDP is considered a marker of adverse maternal and foetal outcomes [6]. Proteinuria defines renal affection. A dipstick test of >1+ warrants further investigations such as an albumin-creatinine ratio (ACR), that can be measured by a single spot urine sample. An ACR cut-off level of 30 mg/mmol can be used to identify proteinuria. Specific tests should be carried out whenever secondary HTN is suspected.

Doppler ultrasound of the uterine arteries (performed after 20 weeks of gestation) can detect those at a higher risk of gestational hypertension, pre-eclampsia, and intrauterine growth retardation [7].

Pre-eclampsia/eclampsia syndrome


Gestational hypertension with significant proteinuria (>0.3 g/24 hrs or ≥30 mg/mmol ACR). As proteinuria may be a late manifestation of pre-eclampsia, it should be suspected when de novo HTN is associated with symptoms (e.g., headache, visual disturbances, abdominal pain, or abnormal laboratory tests). Eclampsia is a severe form of pre-eclampsia associated with generalised tonic-clonic seizures [2]. In a few cases, pre-eclampsia may develop in the early post-partum period.

Risk factors

Women at increased risk of developing pre-eclampsia are primigravida, those with multiple pregnancy, morbid obesity (body mass index [BMI] >35 kg/m2), diabetes mellitus, renal disease or autoimmune diseases (i.e., systemic lupus erythematosus, antiphospholipid syndrome). Chronic pre-existing hypertension, a history of pre-eclampsia in a previous pregnancy or familial history of pre-eclampsia are also considered risk factors for developing pre-eclampsia [8].


This is still unclear, but many theories propose a placental vascular insufficiency due to endothelial dysfunction, vasoconstriction and micro-thrombosis. Oxidative stress of the syncytiotrophoblast (the epithelial covering of the placental villi in contact with maternal blood) is one of the explanations. When stressed, the syncytiotrophoblast releases many factors, including pro-inflammatory cytokines, anti-angiogenic agents, exosomes and cell-free foetal DNA, into the maternal circulation. These disrupt maternal endothelial function resulting in a systemic inflammatory response and cause hypertension and other manifestations of the disease (haematologic, cardiac, neurologic, pulmonary, renal, and hepatic dysfunction) [9]. Genetics may also play a role.


Maternal complications include multiple organ failure. Maternal mortality is estimated to be 9% in the United States of America (USA), which is why the USA preventive task force recommended measuring the BP at every prenatal visit [10]. Foetal growth restriction occurs due to placental insufficiency and is a common cause of premature delivery [8].

Pre-eclampsia accompanied by haemolysis, elevated liver enzymes and low platelets is called HELLP syndrome. HELLP is a life-threatening condition which may be fatal if not detected and treated early. The global mortality rate of HELLP syndrome has been reported to be as high as 25% [11].


Currently, there is no sure way to prevent hypertension and there is no clear role for lifestyle modifications in reducing HDP [2].

The aim of prescribing antihypertensive medications is to decrease progression to severe HTN and to prolong pregnancy till foetal maturity [12].

Hospitalisation is needed for patients with severe HTN.

Antihypertensive drugs

The threshold for initiation of antihypertensive medications is ≥150/95 mmHg for patients with pre-existing HTN and >140/90 mmHg for patients with gestational HTN (with or without proteinuria) and patients with subclinical hypertension-mediated organ damage (HMOD) [1]. The target BP should be <140/90 for all hypertensive pregnant women. Because of the physiological drop of BP in the second trimester, some women become able to withdraw their antihypertensive medication [2].

Both maternal hypertension and maternal antihypertensive use during pregnancy were associated with increased risk of congenital heart diseases (CHDs) such as pulmonary valve stenosis, secundum atrial septal defect, ventricular septal defect and coarctation of the aorta. Hypertensive mothers who reported antihypertensive use had higher risk of these CHDs than untreated mothers [13]. That is why the pregnancy and lactation labelling rule (PLLR) system must be checked before prescribing any drugs to pregnant women.

Drugs for mild HTN


Beta-blockers (BB) are first-line medication during pregnancy and lactation. Labetalol is one of the commonest drugs used in HDP. It can be used parenterally in cases of severe HTN. BB may cause foetal bradycardia or intrauterine growth retardation; thus, proper monitoring of the foetus is essential. Atenolol is better avoided during pregnancy [2].

Alpha methyldopa

This is an ᾳ2-adrenergic agonist that has central nervous system (CNS) and peripheral nervous system effects. It is one of the safest drugs during pregnancy; been used for more than 40 years, with no serious side effects on the mother or the foetus, although it has been largely displaced by labetalol as the first-line agent of choice for most patients. The recommended daily dose of methyldopa is 0.5–3.0 g in 2–4 doses. Side-effects include sleepiness, dry mouth, general malaise, haemolytic anaemia, and hepatopathy [14].

Calcium channel blockers

Calcium channel blockers (CCBs) are among the recommended antihypertensive drugs during pregnancy. Both dihydropyridines and non-dihydropyridines are allowed [2].


The use of diuretics during pregnancy carries a potential risk of oligohydramnios. Unless there is a compelling indication for the use of diuretics (e.g., heart failure), their use is not recommended. Diuretic therapy is better avoided in pre-eclampsia because the plasma volume is contracted [2]. Only loop diuretics are allowed, while thiazide and potassium-sparing diuretics are contraindicated during pregnancy.

Renin-angiotensin-aldosterone system inhibitors

Renin-angiotensin-aldosterone system (RAAS) inhibitors include angiotensin-converting enzyme inhibitors (ACEIs), angiotensin receptor blockers (ARBs), renin inhibitors, non-selective (spironolactone) and selective (eplerenone) aldosterone antagonists.

Recent studies suggest that exposure early in pregnancy during the period of organogenesis does not confer an increase in the risk of malformations [15]. However, animal and human data suggest that RAAS inhibitor use during the second and third trimesters is associated with a higher risk of complications, including renal dysplasia, pulmonary hypoplasia, and growth restriction [16].

The guidelines recommend against the use of RAAS inhibitor drugs during pregnancy and lactation (Class III recommendations). Beta-blockers are used as an alternative to ACEIs and ARBs in younger hypertensive women planning pregnancy [1].

Drugs for severe HTN

HDP emergency is defined as BP ≥170/110 mmHg. It necessitates immediate hospital admission and parenteral antihypertensive medications [2]. Intravenous labetalol and nicardipine as well as oral methyldopa and CCB can be used. Hydralazine is now only used when other drugs fail to control HTN, because of its increased perinatal adverse effects [17].

Treatment of pre-eclampsia/eclampsia syndrome

  • Women at a risk of developing pre-eclampsia should be advised to take 100–150 mg of aspirin daily from weeks 12–36 gestation [18]. Aspirin can decrease the risk of pre-eclampsia by 12% and the risk of premature delivery by 14% [19].
  • Women with a diagnosis of pre-eclampsia should be admitted and offered antihypertensive medications, if not previously given. Intravenous labetalol and nicardipine are usually used to lower the BP but foetal bradycardia is a concern. In case of pulmonary oedema, nitroglycerine infusion is recommended. The consensus is to reduce BP to levels lower than 160/105 mmHg.
  • Intravenous magnesium sulfate is the treatment of choice in patients with eclampsia fits.
  • Delivery of the placenta (and the foetus, of course!) is the only cure for pre-eclampsia; yet, in asymptomatic patients, delivery can be delayed to the 37th week of gestation.

Timing and mode of delivery

Vaginal delivery is preferred unless there are obstetric or medical contraindications.

Delivery at 37 weeks is recommended in uncomplicated patients. Women with pre-eclampsia with visual or haemostatic disorders or HELLP syndrome should be delivered as soon as possible [2].

Management of HTN post-partum

When HTN persists after delivery, antihypertensive drugs should be continued. Almost all drugs are secreted in milk, but in varying amounts [20]. Because of the lack of evidence, most physicians use the same rules applied for drugs during pregnancy in the breastfeeding period. Methyldopa should be avoided because of the risk of post-partum depression.


HDP is a heterogenous disease that increases the risk of maternal and foetal morbidity and mortality. Early detection and management are warranted by routine measurement of BP at the regular antenatal care visits. Obstetricians and cardiologists should share in the management of HDP.


  1. Williams B, Mancia G, Spiering W, Agabiti Rosei E, Azizi M, Burnier M, Clement DL, Coca A, de Simone G, Dominiczak A, Kahan T, Mahfoud F, Redon J, Ruilope L, Zanchetti A, Kerins M, Kjeldsen SE, Kreutz R, Laurent S, Lip GYH, McManus R, Narkiewicz K, Ruschitzka F, Schmieder RE, Shlyakhto E, Tsioufis C, Aboyans V, Desormais I; ESC Scientific Document Group. 2018 ESC/ESH Guidelines for the management of arterial hypertension. Eur Heart J. 2018;39:3021-104. 
  2. Regitz-Zagrosek V, Roos-Hesselink JW, Bauersachs J, Blomstrom-Lundqvist C, Cifkova R, De Bonis M, Iung B, Johnson MR, Kintscher U, Kranke P, Lang IM, Morais J, Pieper PG, Presbitero P, Price S, Rosano GMC, Seeland U, Simoncini T, Swan L, Warnes CA; ESC Scientific Document Group. 2018 ESC Guidelines for the management of cardiovascular diseases during pregnancy. Eur Heart J. 2018;39:3165-241. 
  3. Penny JA, Halligan AW, Shennan AH, Lambert PC, Jones DR, de Swiet M, Taylor DJ. Automated, ambulatory, or conventional blood pressure measurement in pregnancy: which is the better predictor of severe hypertension? Am J Obstet Gynecol. 1998;178:521-6.  
  4. Ray JG, Vermeulen MJ, Schull MJ, Redelmeier DA. Cardiovascular health after maternal placental syndromes (CHAMPS): population-based retrospective cohort study. Lancet. 2005;366:1797-803. 
  5. Magee LA, von Dadelszen P, Singer J, Lee T, Rey E, Ross S, Asztalos E, Murphy KE, Menzies J, Sanchez J, Gafni A, Helewa M, Hutton E, Koren G, Lee SK, Logan AG, Ganzevoort W, Welch R, Thornton JG, Moutquin JM; CHIPS Study Group. The CHIPS Randomized Controlled Trial (Control of Hypertension in Pregnancy Study): Is Severe Hypertension Just an Elevated Blood Pressure? Hypertension. 2016;68:1153-9. 
  6. Schmella MJ, Clifton RG, Althouse AD, Roberts JM. Uric Acid Determination in Gestational Hypertension: Is it as Effective a Delineator of Risk as Proteinuria in High-Risk Women? Reprod Sci. 2015;22:1212-9. 
  7. Cnossen JS, Morris RK, ter Riet G, Mol BW, van der Post JA, Coomarasamy A, Zwinderman AH, Robson SC, Bindels PJ, Kleijnen J, Khan KS. Use of uterine artery Doppler ultrasonography to predict pre-eclampsia and intrauterine growth restriction: a systematic review and bivariable meta-analysis. CMAJ. 2008;178:701-11. 
  8. Bartsch E, Medcalf KE, Park AL, Ray JG; High Risk of Pre-eclampsia Identification Group. Clinical risk factors for pre-eclampsia determined in early pregnancy: systematic review and meta-analysis of large cohort studies. BMJ. 2016;353:i1753. 
  9. Burton GJ, Redman CW, Roberts JM, Moffett A. Pre-eclampsia: pathophysiology and clinical implications. BMJ. 2019;366:l2381.  
  10. Henderson JT, Thompson JH, Burda BU, Cantor A. Preeclampsia Screening: Evidence Report and Systematic Review for the US Preventive Services Task Force. JAMA. 2017;317:1668-83. 
  11. Kota LN, Garikapati K, Kodey PD, Gayathri KB. Study on HELLP syndrome - maternal and perinatal outcome. IJRCOG. 2017;6:714-9. 
  12. Nabhan AF, Elsedawy MM. Tight control of mild-moderate pre-existing or non-proteinuric gestational hypertension. Cochrane Database Syst Rev. 2011;(7):CD006907. 
  13. Fisher SC, Van Zutphen AR, Werler MM, Lin AE, Romitti PA, Druschel CM, Browne ML; National Birth Defects Prevention Study. Maternal Antihypertensive Medication Use and Congenital Heart Defects: Updated Results From the National Birth Defects Prevention Study. Hypertension. 2017;69:798-805. 
  14. Leavitt K, Obican S, Yankowitz J. Treatment and Prevention of Hypertensive Disorders During Pregnancy. Clin Perinatol. 2019;46:173-85.  
  15. Bateman BT, Patorno E, Desai RJ, Seely EW, Mogun H, Dejene SZ, Fischer MA, Friedman AM, Hernandez-Diaz S, Huybrechts KF. Angiotensin-Converting Enzyme Inhibitors and the Risk of Congenital Malformations. Obstet Gynecol. 2017;129:174-84. 
  16. Kaye AB, Bhakta A, Moseley AD, Rao AK, Arif S, Lichtenstein SJ, Aggarwal NT, Volgman AS, Sanghani RM. Review of Cardiovascular Drugs in Pregnancy. J Womens Health (Larchmt). 2019;28:686-97.  
  17. Magee LA, Cham C, Waterman EJ, Ohlsson A, von Dadelszen P. Hydralazine for treatment of severe hypertension in pregnancy: meta-analysis. BMJ. 2003;327:955-60. 
  18. Rolnik DL, Wright D, Poon LC, O'Gorman N, Syngelaki A, de Paco Matallana C, Akolekar R, Cicero S, Janga D, Singh M, Molina FS, Persico N, Jani JC, Plasencia W, Papaioannou G, Tenenbaum-Gavish K, Meiri H, Gizurarson S, Maclagan K, Nicolaides KH.  Aspirin versus Placebo in Pregnancies at High Risk for Preterm Preeclampsia. N Engl J Med. 2017;377:613-22. 
  19. Mammaro A, Carrara S, Cavaliere A, Ermito S, Dinatale A, Pappalardo EM, Militello M, Pedta R. Hypertensive disorders of pregnancy. J Prenat Med. 2009;3:1-5. 
  20. Beardmore KS, Morris JM, Gallery ED. Excretion of antihypertensive medication into human breast milk: a systematic review. Hypertens Pregnancy. 2002;21:85-95.  

Notes to editor


Ghada Sayed Youssef1,2, MD

  1. Assistant Professor of Cardiology, Kasr Al Ainy Hospitals, Cairo University, Cairo, Egypt;
  2. Moderator of High-Risk Pregnancy Unit, Cairo University, Cairo, Egypt


Address for correspondence:

Dr Ghada Sayed Youssef, Kasr Al Ainy Hospitals, Cardiology Department, Cairo University, Cairo, Egypt


Tel: (+20) 11 511 889 99


Author disclosures:

The author has no conflicts of interest to declare.




The content of this article reflects the personal opinion of the author/s and is not necessarily the official position of the European Society of Cardiology.