Note that labetalol therapy should not be used in women with asthma or congestive heart failure
Chronic hypertension in pregrancy
Case 5Dr Barik
A 35-year-old woman elder primi and has a 5-year history ofhypertension wants to become pregnant. She has stopped usingcontraception. Her only medication is lisinopril at a dose of 10 mgper day. Her blood pressure is 124/68 mm Hg,and her body-massindex (the weight in kilograms divided by the square of the heightin meters) is 27. Pregnancy-related deaths(3201 in US, 1991-1997-16%
Classification of Hypertension in Pregnancy From Gifford RW, August PA, Cunningham G, et al: Report of the National High Blood Pressure Education Program Working Group on High Blood Pressure in Pregnancy. Am J Obstet Gynecol 183:S1, 2000 Hypertension (blood pressure ≥140 mm Hg systolic or ≥90 mmChronic hypertension Hg diastolic) present before pregnancy or that is diagnosed before the 20th week of gestation New hypertension with a blood pressure of 140/90 mm Hg on two separate occasions, without proteinuria, arising de novoGestational hypertension after the 20th week of pregnancy. Blood pressure normalizes by 12 weeks post partum. Increased blood pressure above the patients baseline, aPreeclampsia superimposed on chronic hypertension change in proteinuria, or evidence of end-organ dysfunction Proteinuria (>0.3 g during 24 hours or ++ in two urine samples) in addition to new hypertension. Edema is no longer included in the diagnosis because of poor specificity. WhenPreeclampsia-eclampsia proteinuria is absent, suspect the disease when increased blood pressure is associated with headache, blurred vision, abdominal pain, low platelets, or abnormal liver enzymes.
GestationalHypertension – 3.7% in Diagnosis150,000 (NationalCenter for HealthStatics, 2001)CHRONICHYPERTENSION
•BP ≥140/90 mmHg before pregnancy or diagnosed before 20weeks’ gestation (not attributable to gestational trophoblastic disease) or •Hypertension first diagnosed after 20weeks’ gestation and persistent after 12weeks’ postpartumUnderlying hypertension-Essential familial hypertension (90%)
•BP≥ 140/90mmHg for first time duringpregnancy•No proteinuria•BP returns to normal < 12 weeks’ postpartum•Final diagnosis made only postpartum•May have other signs or symptoms ofpreeclampsia, for example, epigastric discomfortor thrombocytopenia
INCIDENCENulliparous women BMI (Kg/m2)Incidence : 5% (wide Morbidity (%)variation) <19.8Influence by Parity, race, 4.3ethnicity, genetic >35predispositionNulliparous 13.3 Total :7.6% / severe : Gestation 3.3% (Hauth, 2000)Risk factor twin Chronic hypertension, 13 multifetal gestation, single maternal old age(>35 5 yrs), obesity, African-
FACTOR RISK RATIORenal disease 20:1Chronic hypertension 10:1Antiphospholipid syndrome 10:1Family history of PIH 5:1Twin gestation 4:1Nulliparity 3:1Age > 40 3:1Diabetes mellitus 2:1African American 1.5:1
New-onset proteinuria≥ 300mg/24hours inhypertensive women but no proteinuriabefore 20 weeks’ gestation.A sudden increase in proteinuria or bloodpressure or platelet count <100,000/mm3 inwomen with hypertension and roteinuriabefore 20weeks’ gestation
Treatment of mild to moderate chronic hypertensionneither benefits the fetus nor prevents preeclampsia.Excessively lowering blood pressure may result indecreased placental perfusion and adverse perinataloutcomes.When BP is 150 to 180/100 to 110 mm Hg,pharmacologic treatment is needed to preventmaternal end-organ damage.
Antihypertensive Therapy Prior to and During Pregnancy1. What is the proper management of young women with mild hypertension?2. What are the benefits of treating mild hypertension in pregnancy?3. Is pharmacological treatment of mild hypertension harmful to mothers, fetuses, and infants?4. Are particular antihypertensive drugs more ffective or harmful than others?
What Are the Benefits of Treating Mild Hypertension in Pregnancy? Data are insufficient to either prove ordisprove effects in perinatal outcome • All trials had inadequate sample size • Most were unblinded • Few women enrolled in first trimester • 15 different drugs or combinations were studied Definite need for multicenter trials
What is the Proper Management of Young Women with Hypertension? No report that addressed the effect of bloodpressure control before conception on fetaloutcomes Women of reproductive age are excluded from randomized trials Only 3 trials in women aged 30-54 years • 8,565 studied • Little data in women < 40 years
Seizure Prophylaxis• Magnesium sulfate• Loading dose of 4 to 6 g diluted in 100 mL of normal saline, given IV over 15 to 20 minutes, followed by a continuous infusion of 1-2 g per hour• Monitor urine output, RR and DTR’s• With renal dysfunction, may require a lower dose
• Low-dose aspirin (75 to 81 mg daily) has small to moderate benefits for the prevention of preeclampsia (NNT = 72), preterm delivery (NNT = 74), and fetal death (NNT = 243). The benefit of aspirin is greatest (NNT = 19) for prevention of preeclampsia in women at highest risk (previous severe preeclampsia, diabetes, chronic hypertension, renal disease, or autoimmune disease). – B• For women with mild preeclampsia, delivery is generally not indicated until 37 to 38 weeks of gestation and should occur by 40 weeks. – C
KEY RECOMMENDATIONS FOR PRACTICE• In women without end-organ damage, chronic hypertension in pregnancy does not require treatment unless the patients blood pressure is persistently greater than 150 to 180/100 to 110 mm Hg. – C• Calcium supplementation decreases the incidence of hypertension and preeclampsia, respectively, among all women (NNT = 11 and NNT = 20), women at high risk of hypertensive disorders (NNT = 2 and NNT = 6), and women with low calcium intake (NNT = 6 and NNT = 13). – A