MANAGEMENTHTN IN

PREGNANCY

DEFINITIONS

The definition of gestational hypertension is somewhat controversial.

Some clinicians therefore recommend close observation of women with an incremental rise in blood pressure by 30 mm Hg systolic or 15 mm Hg diastolic even if absolute blood pressure does notexceed 140/90 mm Hg.

Gestational hypertension is the most frequent cause of hypertension during pregnancy. The incidence ranges between 6% and 29% in nulliparous women and between 2% and 4% in multiparous women.Maternal and perinatal morbidities are substantially increased in women with severe gestational hypertension.

Indeed, these women have increased risk for morbidity compared with women with mild preeclampsia. The rates of abruptio placentae, preterm delivery (at less than 37 and 35 weeks), and small-for-gestational-age (SGA) infants in these women are similar to those seen in women with severe preeclampsia.

INCIDENCE OF CHRONIC HYPERTENSION

The frequency of chronic hypertension in pregnancy is estimated at 1% to 5%.The etiology and severity of chronic hypertension are important considerations in the management of pregnancyChronic hypertension is subdivided into primary (essential) and secondary.

Chronic hypertension during pregnancy can be subclassified as either mild or severe, depending on the systolic and diastolic BP readings. Systolic and diastolic (Korotkoff phase V) BPs of at least 160 mm Hg or 110 mm Hg, respectively, constitute severe hypertension.

Pregnancies complicated by chronic hypertension are at increased risk for the development of superimposed preeclampsia and abruptio placentae. The reported rates of preeclampsia in the literature in mild hypertension rangefrom 14% to 28% .

The rate of preeclampsia in women with severe chronic hypertension ranges from50% to 79%.

The overall rate

of superimposed preeclampsia was 25%. The rate was notaffected by maternal age, race, or presence of proteinuriaearly in pregnancy. However, the rate was significantlygreater in women who had hypertension for at least 4 years(31% versus 22%), in those who had preeclampsia duringa previous pregnancy (32% versus 23%), and in thosewhose diastolic BP was 100 mm Hg or higher (42% versus24%).1

Antepartum Management of MildGESTATIONAL HYPERTENSION

These patients require close observation of maternal and fetal conditions.

Maternal evaluations require weekly prenatal visits, education about reporting preeclamptic symptoms,and evaluation of complete blood count, platelet count, and liver enzymes.

Fetal evaluation includes ultrasound examination of fluid and estimated fetal weight at the timeof diagnosis and weekly non stress testing.

Restriction dietary salt as well as physical activity has not proved beneficial

Control of maternal BP with antihypertensive drugs does not improve pregnancy outcome In the absence of progression to severe hypertension orpreeclampsia, women with gestational hypertension cancontinue pregnancy until 37 weeks’ gestation

In women with gestational hypertension full assessment should be carried out in a secondary care setting by a healthcare professional who is trained in the management of hypertensive disorders.

• nulliparity

• age 40 years or older

• pregnancy interval of more than 10 years

• family history of pre-eclampsia

• multiple pregnancy

• BMI of 35 kg/m² or more

• gestational age at presentation

• previous history of pre-eclampsia or gestational hypertension

• pre-existing vascular disease

• pre-existing kidney disease.

In women with gestational hypertension who have given birth, measure blood pressure:• daily for the first 2 days after birth

• at least once between day 3 and day 5 after birth

• as clinically indicated if antihypertensive treatment is changed after birth.In women with gestational hypertension who have given birth:

• continue use of antenatal antihypertensive treatment

• consider reducing antihypertensive treatment if their blood pressure falls below140/90 mmHg

• reduce antihypertensive treatment if their blood pressure falls below 130/80 mmHg.If a woman has taken methyldopa† to treat gestational hypertension, stop within 2 days ofbirth.For women with gestational hypertension who did not take antihypertensive treatment andhave given birth, start antihypertensive treatment if their blood pressure is higher than149/99 mmHg.

Offer women who have had gestational hypertension and remain on antihypertensivetreatment 2 weeks after transfer to community care, a medical review.

Offer women who have had gestational hypertension a medical review at the postnatalreview (6–8 weeks after the birth).

Offer women who have had gestational hypertension and who still need antihypertensivetreatment at the postnatal review (6–8 weeks after the birth) a specialist assessment of theirhypertension.___________________________________________________________

Recommended Management of chronic  Hypertension

Based on the avail- able data, there is no compelling evidence that short-term antihypertensive therapy is benefcial for the mother or the fetus in the setting of low-risk hypertension except for a reduction in the rate of exacerbation of hypertension.

Therapy suggested:

Secondary HTNEnd organ damageDyslipidemiaMaternal age over 40Microvascular diseaseHistory strokePrevious prenatal loss

Women with long-standing hypertension for several years, particularly those with a history of poor compliance or poor BP control, should be evaluated for target organ damage, including :

left ventricular hypertrophy, Retinopathy, and renal injury an ECG examination and echocardiography if the ECG is abnormal, ophthalmologic evaluation, and creatinine clearance.

Methyldopa remains the drug most commonly recommended to treat hypertension during pregnancy

For women with diabetes mellitus and vascular disease, oral nifedipine is recommended.

Systolic BP ≥ 160-170 Diastolic BP ≥ 100-110

Labetalol: 20 mg IV 40 60 80 80

Constant Infusion: 1-2 mg/minInstead of intermitent therapy

10 min no response

OR

15-20 min no response

Calcium Cahnnel Blockers: SR nifidipine 10-20 mg Q 30 min

Nitroprusside: 0.25-3 mcg/kg/min

Do not offer birth to women with chronic hypertension whose blood pressure is lower than 160/110 mmHg, with or without antihypertensive treatment, before 37 weeks. Offer birth to women with refractory severe chronic hypertension, after a course of corticosteroids (if required) has been completed.