Hypertensive Disorders In pregnancy Dr:ishraq mohammed

Introduction Hypertensive disorders complicate 5 to 10 percent of all pregnancies, and together they form one member of the deadly triad, along with hemorrhage and infection, that contribute greatly to maternal morbidity and mortality rates With hypertension, the preeclampsia syndrome, either alone or superimposed on chronic hypertension, is the most dangerous. New-onset nonproteinuric hypertension during pregnancy—termed gestational hypertension—is followed by signs and symptoms of preeclampsia almost half the time, and preeclampsia is identified in 3.9 percent of all pregnancies

Classification The term gestational hypertention describes any new-onset uncomplicated hypertension during pregnancy when no evidence of the preeclampsia syndrome was apparent. Gestational hypertension—formerly termed pregnancy-induced hypertension. If preeclampsia syndrome does not develop and hypertension resolves by 12 weeks postpartum, it is redesignated as transient hypertension Preeclampsia and eclampsia syndrome Preeclampsia syndrome superimposed on chronic hypertension Chronic hypertension.

Diagnosis of Hypertensive Disorders Complicating Pregnancy Gestational Hypertension: Systolic BP 140 or diastolic BP 90 mm Hg for first time during pregnancy No proteinuria BP returns to normal before 12 weeks postpartum Final diagnosis made only postpartum May have other signs or symptoms of preeclampsia, for example, epigastric discomfort

BP 140/90 mm Hg after 20 weeks' gestation Preeclampsia: Minimum criteria: BP 140/90 mm Hg after 20 weeks' gestation Proteinuria 300 mg/24 hours or 1+ dipstick Increased certainty of preeclampsia: BP 160/110 mm Hg Proteinuria 2.0 g/24 hours or 2+ dipstick Serum creatinine >1.2 mg/dL unless known to be previously elevated Platelets < 100,000/L Microangiopathic hemolysis—increased LDH Elevated serum transaminase levels—ALT or AST Persistent headache or other cerebral or visual disturbance Persistent epigastric pain

Superimposed Preeclampsia On Chronic Hypertension: Seizures that cannot be attributed to other causes in a woman with preeclampsia Superimposed Preeclampsia On Chronic Hypertension: New-onset proteinuria 300 mg/24 hours in hypertensive women but no proteinuria before 20 weeks' gestation A sudden increase in proteinuria or blood pressure or platelet count < 100,000/L in women with hypertension and proteinuria before 20 weeks' gestation Chronic Hypertension: BP 140/90 mm Hg before pregnancy or diagnosed before 20 weeks' gestation not attributable to gestational trophoblastic disease or Hypertension first diagnosed after 20 weeks' gestation and persistent after 12 weeks postpartum

Diagnosis Hypertension is diagnosed when appropriately taken blood pressure exceeds 140 mm Hg systolic or 90 mm Hg diastolic. Korotkoff phase V is used to define diastolic pressure. In the past, it had been recommended that an incremental increase from midpregnancy values by 30 mm Hg systolic or 15 mm Hg diastolic pressure be used as diagnostic criteria, even when absolute values were below 140/90 mm Hg. These criteria are no longer recommended because evidence shows that such women are not likely to experience increased adverse pregnancy outcomes

That said, women who have a rise in pressure of 30 mm Hg systolic or 15 mm Hg diastolic should be seen more frequently. There is no doubt that eclamptic seizures develop in some women whose blood pressures have been below 140/90 mm Hg. Edema is also no longer used as a diagnostic criterion because it is too common in normal pregnancy to be discriminant.

Gestational Hypertension The diagnosis of gestational hypertension is made in women whose blood pressure reaches 140/90 mm Hg or greater for the first time after midpregnancy, but in whom proteinuria is not identified .Almost half of these women subsequently develop preeclampsia syndrome, which includes signs such as proteinuria and thrombocytopenia or symptoms such as headaches or epigastric pain. Gestational hypertension is reclassified as transient hypertension if evidence for preeclampsia does not develop, and the blood pressure returns to normal by 12 weeks postpartum.

Proteinuria is the surrogate objective marker that defines the system wide endothelial leak, which characterizes the preeclampsia syndrome. Even so, when blood pressure increases appreciably, it is dangerous to both mother and fetus to ignore this rise because proteinuria has not yet developed. As 10 percent of eclamptic seizures develop before overt proteinuria is identified.

Preeclampsia preeclampsia is best described as a pregnancy-specific syndrome that can affect virtually every organ system. Although preeclampsia is much more than simply gestational hypertension with proteinuria, appearance of proteinuria remains an important objective diagnostic criterion. Proteinuria is defined by 24-hour urinary protein excretion exceeding 300 mg, a urine protein:creatinine ratio of 0.3, or persistent 30 mg/dL (1+ dipstick) protein in random urine samples.

Urine concentrations vary widely during the day, and so too will dipstick readings. Thus, assessment may even show a 1+ to 2+ value from concentrated urine specimens from women who excrete < 300 mg/day. As discussed in Proteinuria, it is likely that determination of a spot urine:creatinine ratio will be a suitable replacement for a 24-hour measurement.

the more severe the hypertension or proteinuria, the more certain is the diagnosis of preeclampsia as well as its adverse outcomes. Similarly, abnormal laboratory findings in tests of renal, hepatic, and hematological function increase the certainty of preeclampsia. Persistent premonitory symptoms of eclampsia, such as headache and epigastric pain, also increase the certainty. That said, some women may have atypical preeclampsia with all aspects of the syndrome, but without hypertension or proteinuria, or both

Indicators of Severity of Preeclampsia Abnormality Nonsevere Diastolic blood pressure <110 mm Hg Systolic blood pressure <160 mm Hg Proteinuria <= 2+ Headache Absent Visual disturbances Absent Upper abdominal pain Absent Severe >=110 mm Hg >=160 mm Hg >=3+ Present Present Present

Indicators of Severity of Preeclampsia Fetal growth restriction Absent obvios Pulmonary oedema Absent present oliguria absent present Convulsion (eclampsia) Serum creatinine Thrombocytopenia Serum transaminase elevation Absent Normal minimal Present Elevated marked

Eclampsia The onset of convulsions in a woman with preeclampsia that cannot be attributed to other causes is termed eclampsia. The seizures are generalized and may appear before, during, or after labor. In older reports, up to 10 percent of eclamptic women, especially nulliparas, did not develop seizures until after 48 hours postpartum .And it have been reported that up to a fourth of eclamptic seizures developed beyond 48 hours postpartum .Delayed postpartum eclampsia continues to occur in less than 10 percent of.

Preeclampsia Superimposed on Chronic Hypertension All chronic hypertensive disorders, regardless of their cause, predispose to development of superimposed preeclampsia and eclampsia. These disorders can create difficult problems with diagnosis and management in women who are not seen until after midpregnancy. This is because blood pressure normally decreases during the second and early third trimesters in both normotensive and chronically hypertensive women.

Thus, a woman with previously undiagnosed chronic vascular disease, who is seen for the first time at 20 weeks, frequently has blood pressure within the normal range. During the third trimester, however, as blood pressure returns to its originally hypertensive level, it may be difficult to determine whether hypertension is chronic or induced by pregnancy. Even a careful search for evidence of pre-existing end-organ damage may be difficult as many of these women have mild disease. Thus, there may be no evidence of ventricular hypertrophy, chronic retinal vascular changes, or mild renal dysfunction.

In some women with chronic hypertension, blood pressure increases to obviously abnormal levels, and this is typically after 24 weeks. If accompanied by proteinuria, then superimposed preeclampsia is diagnosed. Superimposed preeclampsia commonly may develop earlier in pregnancy than "pure" preeclampsia. Superimposed disease tends to be more severe and often is accompanied by fetal-growth restriction.

Incidence and Risk Factors Preeclampsia often affects young and nulliparous women, whereas older women are at greater risk for chronic hypertension with superimposed preeclampsia. Also, the incidence is markedly influenced by race and ethnicity—and thus by genetic predisposition. Other factors include environmental, socioeconomic, and even seasonal influences.

Other risk factors associated with preeclampsia include obesity, multifetal gestation, maternal age older than 35 years, and African-American ethnicity.The relationship between maternal weight and the risk of preeclampsia is progressive. It increases from 4.3 percent for women with a body mass index (BMI) < 20 kg/m2 to 13.3 percent in those with a BMI > 35 kg/m2. In women with a twin gestation compared with those with singletons, the incidence of gestational hypertension—13 versus 6 percent, and the incidence of preeclampsia—13 versus 5 percent, are both significantly increased.The incidence is unrelated to zygosity

Although smoking during pregnancy causes a variety of adverse pregnancy outcomes, it has consistently been associated with a reduced risk of hypertension during pregnancy ,Placenta previa has also been reported to reduce the risk of hypertensive disorders in pregnancy .

Eclampsia Incidence Because it is somewhat preventable by adequate prenatal care, the incidence of eclampsia has decreased over the years. In developed countries, its incidence probably averages 1 in 2000 deliveries

Etiopathogenesis Any satisfactory theory concerning the etiology and pathogenesis of preeclampsia must account for the observation that gestational hypertensive disorders are more likely to develop in women who: Are exposed to chorionic villi for the first time Are exposed to a superabundance of chorionic villi, as with twins or hydatidiform mole Have preexisting renal or cardiovascular disease Are genetically predisposed to hypertension developing during pregnancy.

Etiology Instead of being simply "one disease," preeclampsia appears to be a culmination of factors that likely involve a number of maternal, placental, and fetal factors. Those currently considered important include: Placental implantation with abnormal trophoblastic invasion of uterine vessels Immunological maladaptive tolerance between maternal, paternal (placental), and fetal tissues Maternal maladaptation to cardiovascular or inflammatory changes of normal pregnancy Genetic factors including inherited predisposing genes as well as epigenetic influences.

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