Hypertension in pregnancy

Global Burden
﴿ Approximately 830 women die from pregnancy or childbirth-
related complications around the world every day
﴿ 99% occur in developing countries
﴿ Hypertension before pregnancy or during early pregnancy is
associated with a twofold increased risk of gestational diabetes
mellitus
Maternal mortality Fact sheet by WHO: November 2016
Available at: http://www.who.int/mediacentre/factsheets/fs348/en/
Last accessed: 23/11/2017

Classification
1. Pre-eclampsia & Eclampsia
2. Chronic Hypertension – HT since before pregnancy
3. Chronic Hypertension with Superimposed Preeclampsia
4. Gestational Hypertension – HT after 20 weeks
Obstet Gynecol. 2013 Nov;122(5):1122-31

Risk factors for Hypertension during pregnancy
﴿ Pre-existing medical diseases
– Diabetes, chronic hypertension, chronic kidney disease or autoimmune
disease, or the occurrence of hypertensive disease during a previous
pregnancy
﴿ Other factors produce more modest increases in risk, such as
– Obesity, primiparity, age, a family history of hypertensive disorders of
pregnancy, or a blood pressure at the higher end of the normal range
for age
NICE Clinical Guidelines, No. 107.
National Collaborating Centre for Women's and Children's Health (UK).

Preeclampsia – Incidence
﴿ 8-10% Worldwide
﴿ In developing countries, a woman is seven times as likely to
develop preeclampsia than a woman in a developed country;
10-25% of these cases result in maternal death
﴿ Common factor in preterm delivery and accounts for 20% of all
neonatal intensive care admissions
﴿ Results in 16% of maternal deaths in low- and -middle income
countries
Maternal mortality in 2005: estimates developed by WHO, UNICEF, UNIFPA and the World Bank, Geneva, World Health
Organization, 2007
https://www.mhtf.org/2017/05/22/world-preeclampsia-day-reducing-preventable-deaths-from-preeclampsia/

Preeclampsia – Diagnostic Criteria
Blood Pressure
1. ≥140/90 mmHg on two occasions at least 4 hours apart >20 week of gestation
in women with previously normal BP
2. ≥160/110 mmHg hypertension can be confirmed in short interval (Minutes) to
facilitate timely antihypertensive therapy
&
Proteinuria ≥300mg/24 hour urine collection or Protein/Creatinine ratio ≥0.3 mg/dl
Or in the absence of proteinuria, new onset hypertension with new onset of any of the following:
Thrombocytopenia Platelet count <100,000/microlitre
Renal Insufficiency
Serum creatinine concentration >1.1mg/dl or a doubling of serum creatinine conc.
In the absence of other renal diseases
Impaired Renal Function Elevated concentration of liver transaminase to twice normal concentration
Pulmonary Edema & Cerebral or Visual Symptoms

Preeclampsia – Complications
﴿ Maternal
– Fits (Eclampsia)
– HELLP syndrome (hemolysis, elevated liver enzymes, low platelet count)
– Stroke
﴿ Foetal
– Intrauterine Growth Restriction (IUGR)
– Neonatal Respiratory Distress Syndrome
– Stillbirth
https://www.nhs.uk/conditions/pre-eclampsia/complications/

Preeclampsia – Treatment
Degree of hypertension Mild
(140/90 to
149/99 mmHg)
Moderate
(150/100 to
159/109 mmHg)
Severe
(160/110 mmHg or
higher)
Treat No With oral labetalol
†
as first-line treatment to keep:
BP <150/100 mmHg
Measure blood
pressure
At least four times a
day
At least four times a
day
More than four times a
day, depending on
clinical circumstances
Test for proteinuria Do not repeat quantification of proteinuria
Blood tests Monitor using the following tests twice a week: kidney function, electrolytes,
full blood count, transaminases, bilirubin
Hypertension in pregnancy: Diagnosis and management, Clinical guideline [CG107], Published: August 2010; Last updated: January 2011
Available at: https://www.nice.org.uk/guidance/cg107/chapter/1-guidance#management-of-pregnancy-with-gestational-hypertension
Last Accessed on: 23/11/2017

Chronic Hypertension – Incidence
﴿ Chronic hypertension occurs in up to 22% of women of
childbearing age
﴿ 20-25% of women with chronic hypertension develop
preeclampsia during pregnancy
Carson MP. Hypertension and Pregnancy: Overview. Jun 27,2017.
Available at: https://emedicine.medscape.com/article/261435-overview. Last accessed on 23rd November 2017.

Chronic Hypertension
﴿ Preexisting Hypertension
﴿ Definition
– Systolic pressure ≥ 140 mmHg, diastolic pressure ≥90 mmHg, or both
– Presents before 20th week of pregnancy or persists longer then 12
weeks postpartum
﴿ Causes
– Primary = “Essential Hypertension”
– Secondary = Result of other medical condition (e.g.: renal disease)

Chronic Hypertension – Complications
﴿ Preeclampsia (up to 40% Risk)
﴿ Cesarean delivery
﴿ Postpartum hemorrhage

Chronic Hypertension – Management
﴿ Usually do not require antihypertensive therapy because blood
pressure drops during normal pregnancy
﴿ If BP exceeds 160/100 mm Hg, drug treatment is recommended
﴿ Patient should be closely monitored & laboratory investigations
for preeclampsia should be repeated if the patient‘s blood
pressure increases or if she develops signs or symptoms of
preeclampsia

Chronic Hypertension with
Superimposed Preeclampsia (CHSP)
﴿ Develops in 13-40% of women with chronic hypertension
﴿ Associated with considerable maternal-fetal morbidity and
mortality
– CHSP without severe feature: only manifestation is elevation in BP to
levels <160/110mmHg & proteinuria
– CHSP with severe feature: Presence of organ dysfunction

CHSP: Diagnosis
﴿ Women with hypertension only in early gestation & women with
proteinuria before/after 20 weeks of gestation who
1. Experience a sudden exacerbation of hypertension (Need escalate the
dose of current meds)
2. Sudden increase in liver enzymes to abnormal levels
3. Reduction in platelet count <100,000/microlitre
4. Right upper quadrant pain & severe headaches
5. Pulmonary congestion or edema
6. Renal insufficiency (Creatinine level doubling or increasing ≥1.1 mg/dl)
7. Sudden increase in protein excretion

CHSP: Treatment
﴿ Antepartum Management
– Corticosteroids
– Magnesium Sulfate for seizure prophylaxis
﴿ Ongoing management and timing of delivery is based on
gestational age & disease severity

Gestational Hypertension
﴿ Hypertension with onset >20 weeks’ gestation without any other
features of preeclampsia
﴿ Also called as pregnancy induced hypertension which gets
normalized postpartum
﴿ Of women with apparent gestational hypertension, about ⅓
develop preeclampsia
In the absence of features of preeclampsia,
maternal and fetal outcomes are usually normal
However, it may be a harbinger of chronic hypertension later in life

Gestational Hypertension: Treatment
Degree of
hypertension
Mild
(140/90 to
149/99 mmHg)
Moderate
(150/100 to
159/109 mmHg)
Severe
(160/110 mmHg or higher)
Treat No With oral labetalol
†
as first-line treatment to keep: BP <150/100
Measure blood
pressure
Not more than once a
week
At least twice a week At least four times a day
Test for
proteinuria
At each visit using automated reagent-strip reading device or urinary protein:creatinine
ratio
Blood tests Only those for routine
antenatal care
Test kidney function, electrolytes, full blood count,
transaminases, bilirubin, Do not carry out further blood tests if
no proteinuria at subsequent visits
Hypertension in pregnancy: Diagnosis and management, Clinical guideline [CG107], Published: August 2010; Last updated: January 2011
Available at: https://www.nice.org.uk/guidance/cg107/chapter/1-guidance#management-of-pregnancy-with-gestational-hypertension
Last Accessed on: 23/11/2017

MEDICATIONS FOR
HYPERTENSION IN PREGNANCY

Antihypertensives for BP Control in Pregnancy
Atenolol Captopril Enalapril
Mechanism Beta Blocker ACE Inhibitor ACE Inhibitor
Pregnancy Avoid in first and second
trimester. Associated with
fetal growth restriction and
bradycardia, reduces
uteroplacental blood flow
No – associated with severe
fetal anomaly, fetal
nephropathy, and
intrauterine death
No – associated with severe
fetal anomaly, fetal
nephropathy, and intrauterine
death
Breast-feeding No known evidence of harm
(NICE). Second line after
labetalol
Recommended by Society
of Obstetricians and
Gynecologists of
Canada(SOGC). No known
evidence of harm (NICE)
Not for preterm infants. No
known evidence of harm
(NICE)Particularly for women
needing cardiac/renal
protection
Postnatal Yes Yes Yes
Side-effects Risk of fetal growth
restriction and bradycardia
in pregnancy
Cough Cough
Contraindications Asthma
Integrated Blood Pressure Control 2016:9 79–94

Labetalol Methyldopa
Mechanism Beta blocker Alpha 2 agonist
Pregnancy Yes. Can be given intravenously for
rapid control of severe resistant
hypertension
Yes, including first trimester. Longest post-
marketing surveillance data
Breast-feeding Very small amounts in breast milk. No
known evidence of harm (NICE)
No known evidence of harm (NICE)
Postnatal Yes NICE says avoid
Side-effects Tachycardia Depression, headache, reduced variability on
CTG, hepatitis
Contraindications Asthma Mental health disorders, Hepatic disease

Hydralazine Nifedipine
Mechanism Vasodilator Calcium channel blocker
Pregnancy Used intravenously for rapid blood
pressure control. May be associated
with neonatal thrombocytopenia. Long
history of use. Avoid rapid intravenous
bolus because of risk of hypotension
After 20 weeks. Available in short acting
forms for rapid blood pressure control and
long acting for long-term maintenance
therapy. May be used simultaneously with
magnesium sulfate. May inhibit labor
Breast-feeding Excreted in breast milk, at levels too low
to be harmful
No known evidence of harm (NICE).
Amounts in breast milk too small to be
harmful.
Second line: Amlodipine
Postnatal Yes Yes
Side-effects Headache

Role of Amlodipine in Pregnancy
﴿ Exposure to amlodipine in the first trimester of pregnancy and
during breastfeeding reported no teratogenic effects and it is
compatible with breastfeeding1
﴿ A pilot study demonstrates similar effects on maternal
complications, pre-term births, mean birth weight or in the
proportion of small for gestational age infants among patients
receiving aspirin or amlodipine2
1. Hypertens Pregnancy. 2007;26(2):179-87
2. J Matern Fetal Neonatal Med. 2014 Sep;27(13):1291-4

LATEST
HYPERTENSION
GUIDELINES

Guideline Recommendations
Class of Recommendation (COR): CLASS I (Strong) Benefit >>> Risk
Level of Evidence (LOE): Level C-LD (Limited Data)
Hypertension. 2017;00:e000-e000
Class of Recommendation (COR): CLASS III (Strong) Risk > Benefit

Future Risk & Screening
﴿ All women who have had a hypertensive complication in
pregnancy should receive postnatal counseling regarding the
management of future pregnancies
﴿ For women with
– Gestational hypertension, the risk of recurrence of hypertension in the
next pregnancy is 16%–47% and the risk of preeclampsia is 2%–7%
– Preeclampsia, the risk of recurrence is 16% if they delivered at term,
25% if they delivered before 34 weeks, and 55% if they delivered before
28 weeks

Future Risk & Screening
﴿ These women should be advised
– low-dose aspirin as prophylaxis against preeclampsia for next
pregnancy
– More frequent BP and urine dipstick monitoring in pregnancy
– In case of chronic hypertension, BP should be stabilized on medications
safe to use in first trimester, prior to attempting to conceive
– Women who have had preeclampsia and delivered before 34 weeks
should be screened for anti-phospholipid syndrome
Women with hypertensive disease in pregnancy or
puerperium have an increased risk of CVD in future

Hypertension in pregnancy

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