Chapter 007. Medical Disorders during Pregnancy (Part 2)

Preeclampsia: Treatment Preeclampsia resolves within a few weeks after delivery. For pregnant women with preeclampsia prior to 37 weeks gestation, delivery reduces the mothers morbidity but exposes the fetus to the risk of premature delivery. The management of preeclampsia is challenging because it requires the clinician to balance the health of both mother and fetus simultaneously and to make management decisions that afford both the best opportunities for infant survival. In general, prior to term, women with mild preeclampsia can be managed conservatively with bed rest, close monitoring of blood pressure and renal function, and careful fetal surveillance. For...
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Chapter 007. Medical Disorders during Pregnancy (Part 2) Chapter 007. Medical Disorders during Pregnancy (Part 2) Preeclampsia: Treatment Preeclampsia resolves within a few weeks after delivery. For pregnantwomen with preeclampsia prior to 37 weeks gestation, delivery reduces themothers morbidity but exposes the fetus to the risk of premature delivery. Themanagement of preeclampsia is challenging because it requires the clinician tobalance the health of both mother and fetus simultaneously and to makemanagement decisions that afford both the best opportunities for infant survival. Ingeneral, prior to term, women with mild preeclampsia can be managedconservatively with bed rest, close monitoring of blood pressure and renalfunction, and careful fetal surveillance. For women with severe preeclampsia,delivery is recommended unless the patient is eligible for expectant managementin a tertiary hospital setting. Expectant management of severe preeclampsiaremote from term affords some benefits for the fetus with significant risks for themother. The definitive treatment of preeclampsia is delivery of the fetus andplacenta. For women with severe preeclampsia, aggressive management of bloodpressures > 160/110 mmHg reduces the risk of cerebrovascular accidents.Intravenous labetalol or hydralazine are the drugs most commonly used to managepreeclampsia. Intravenous hydralazine may be associated with more episodes ofmaternal hypotension than labetalol. Alternative agents such as calcium channelblockers may be used. Elevated arterial pressure should be reduced slowly toavoid hypotension and a decrease in blood flow to the fetus. Angiotensin-converting enzyme (ACE) inhibitors as well as angiotensin-receptor blockersshould be avoided in the second and third trimesters of pregnancy because of theiradverse effects on fetal development. Pregnant women treated with ACE inhibitorsoften develop oligohydramnios, which may be caused by decreased fetal renalfunction. Magnesium sulfate is the treatment of choice for the prevention andtreatment of eclamptic seizures. Two large randomized clinical trials havedemonstrated the superiority of magnesium sulfate over phenytoin and diazepam,and a recent large randomized clinical trial has demonstrated the efficacy ofmagnesium sulfate in reducing the risk of seizure and possibly reducing the risk ofmaternal death. Magnesium may prevent seizures by interacting with N-methyl-D-aspartate (NMDA) receptors in the CNS. Given the difficulty of predictingeclamptic seizures on the basis of disease severity, it is recommended that once thedecision to proceed with delivery is made, all patients carrying a diagnosis ofpreeclampsia be treated with magnesium sulfate (see Regimens, below). Regimens for the Administration of Magnesium Sulfate for SeizureProphylaxis in Women in Labor with Preeclampsia Intramuscular Intravenous 10 g (5 g IM deep in 6-g bolus over 15 mineach buttock)a 1–3 g/h by continuous infusion pump 5 g IM deep q4h, May be mixed in 100 mL crystalloid; if givenalternating sides by intravenous push, make up as 20% solution; push at maximum rate of 1 g/min 40-g MgSO4·7H2O in 1000 mL Ringers lactate; run at 25–75 mL/h (1–3 g/h)a a Made up as 50% solution Chronic Essential Hypertension Pregnancy complicated by chronic essential hypertension is associated withintrauterine growth restriction and increased perinatal mortality. Pregnant womenwith chronic hypertension are at increased risk for superimposed preeclampsia andabruptio placenta. Women with chronic hypertension should have a thoroughprepregnancy evaluation, both to identify remediable causes of hypertension andto ensure that the prescribed antihypertensive agents are not associated with anadverse outcome of pregnancy (e.g., ACE inhibitors, angiotensin-receptorblockers). -Methyldopa, labetalol, and nifedipine are the most commonly usedmedications for the treatment of chronic hypertension in pregnancy. Baselineevaluation of renal function is necessary to help differentiate the effects of chronichypertension versus superimposed preeclampsia should the hypertension worsenduring pregnancy. There are no convincing data that demonstrate that treatment ofmild chronic hypertension improves perinatal outcome.