Chapter 007. Medical Disorders during Pregnancy (Part 2) pdf

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' ges

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 mother's 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 women with severe preeclampsia,

delivery is recommended unless the patient is eligible for expectant management

in a tertiary hospital setting Expectant management of severe preeclampsia remote from term affords some benefits for the fetus with significant risks for the mother

The definitive treatment of preeclampsia is delivery of the fetus and placenta For women with severe preeclampsia, aggressive management of blood pressures > 160/110 mmHg reduces the risk of cerebrovascular accidents Intravenous labetalol or hydralazine are the drugs most commonly used to manage preeclampsia Intravenous hydralazine may be associated with more episodes of maternal hypotension than labetalol Alternative agents such as calcium channel blockers may be used Elevated arterial pressure should be reduced slowly to

avoid hypotension and a decrease in blood flow to the fetus

Angiotensin-converting enzyme (ACE) inhibitors as well as angiotensin-receptor blockers should be avoided in the second and third trimesters of pregnancy because of their adverse effects on fetal development Pregnant women treated with ACE inhibitors

often develop oligohydramnios, which may be caused by decreased fetal renal function

Magnesium sulfate is the treatment of choice for the prevention and treatment of eclamptic seizures Two large randomized clinical trials have demonstrated the superiority of magnesium sulfate over phenytoin and diazepam, and a recent large randomized clinical trial has demonstrated the efficacy of magnesium sulfate in reducing the risk of seizure and possibly reducing the risk of

maternal death Magnesium may prevent seizures by interacting with

N-methyl-D-aspartate (NMDA) receptors in the CNS Given the difficulty of predicting eclamptic seizures on the basis of disease severity, it is recommended that once the decision to proceed with delivery is made, all patients carrying a diagnosis of preeclampsia be treated with magnesium sulfate (see Regimens, below)

Regimens for the Administration of Magnesium Sulfate for Seizure Prophylaxis in Women in Labor with Preeclampsia

Intramuscular Intravenous

6-g bolus over 15 min

10 g (5 g IM deep in

each buttock)a

1–3 g/h by continuous infusion pump

5 g IM deep q4h,

alternating sides

May be mixed in 100 mL crystalloid; if given

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 with intrauterine growth restriction and increased perinatal mortality Pregnant women with chronic hypertension are at increased risk for superimposed preeclampsia and abruptio placenta Women with chronic hypertension should have a thorough prepregnancy evaluation, both to identify remediable causes of hypertension and

to ensure that the prescribed antihypertensive agents are not associated with an adverse outcome of pregnancy (e.g., ACE inhibitors, angiotensin-receptor blockers) -Methyldopa, labetalol, and nifedipine are the most commonly used medications for the treatment of chronic hypertension in pregnancy Baseline evaluation of renal function is necessary to help differentiate the effects of chronic hypertension versus superimposed preeclampsia should the hypertension worsen during pregnancy There are no convincing data that demonstrate that treatment of mild chronic hypertension improves perinatal outcome