Chronic Hypertension in Pregnancy


The following are 10 points to remember about chronic hypertension in pregnancy:

1. Chronic hypertension in pregnancy is defined as a systolic blood pressure of at least 140 mm Hg or a diastolic blood pressure of at least 90 mm Hg prior to pregnancy, or prior to 20 weeks’ gestation if a patient first presents during pregnancy.

2. Women with chronic hypertension have an increased risk of pregnancy-related complications, including pre-eclampsia, placental abruption, fetal growth restriction, preterm birth, and cesarean section.

3. Detailed prepregnancy counseling and evaluation should be provided to women with chronic hypertension who of are childbearing age. This should include education as to the maternal and fetal risks of pregnancy, as well as which medical therapies might be contraindicated during pregnancy.

4. Methyldopa is the antihypertensive with the largest quantity of data regarding fetal safety. Somnolence is a common side effect, which may limit its use.

5. Labetalol is an effective antihypertensive, which is safe in pregnancy. The use of beta-blockers has been associated with fewer episodes of severe hypertension than the use of methyldopa.

6. While treatment of chronic hypertension in pregnancy reduces the risk of severe hypertension, it does not decrease the risk of severe pre-eclampsia, placental abruption, or fetal growth restriction, or improve fetal outcomes.

7. Guideline groups disagree on thresholds for initiation of therapy and targets for therapy, although a reasonable goal is to maintain blood pressures from 130/80 mm Hg to 150/100 mm Hg.

8. Angiotensin-converting enzyme inhibitors are contraindicated in pregnancy, as they have been associated with oligohydramnios and neonatal anuria, growth abnormalities, skull hypoplasia, and fetal death. Angiotensin-receptor blockers are also contraindicated.

9. Blood pressure can decrease during the second trimester of pregnancy. Women on antihypertensives at the onset of pregnancy should be closely monitored, and their medications decreased or discontinued as necessary.

10. Most antihypertensives are compatible with breastfeeding. Data are lacking for angiotensin-receptor blockers in breastfeeding, so other agents should be considered.

Clinical Topics: Prevention, Hypertension

Keywords: Methyldopa, Risk, Labetalol, Premature Birth, Counseling, Oligohydramnios, Fetal Death, Cardiovascular Diseases, Cesarean Section, Breast Feeding, Pregnancy Complications, Pregnancy, Hypertension, Pregnancy Trimesters, Angiotensin Receptor Antagonists, Fetal Growth Retardation, Intraocular Pressure, Fetal Development, Pre-Eclampsia, Family Planning Services, Skull

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