Pregnancy-Induced Hypertension (PIH)-妊娠高血压(妊高征)

– Eclampsia:
• Pre-eclampsia + convulsions.
Superimposed pre-eclampsia or eclampsia:
– Development of pre-eclampsia or eclampsia in pre-existing hypertension detected by a further increase of 30 mmHg or more in systolic blood pressure or 15 mmHg or more in diastolic blood pressure.
Hypertensive Disorders in Pregnancy
Classification
1. PRE-EXISTING (CHRONIC) HYPERTENSION 2. PRE-ECLAMPSIA 1. Differential Diagnosis 2. Complications 3. Treatment 4. ECLAMPSIA
• Blood pressure falls by the second trimester in most of cases, but rises during the third trimester to a level some what above that in early pregnancy. • Deterioration of the underlying disease.
How to measure the blood pressure in pregnancy 3
• Let air out slowly so that mercury falls steadily by 2-3 mm/sec. • Blood pressure measurement phases (Korotkoff):
• Secondary to cardiovascular disease: e.g.
– Coarctation of the aorta. – Polyartheritis nodosa. – Systemic lupus erythematosus.
PRE-EXISTING (CHRONIC) HYPERTENSION
Pathological Changes
• Vasospasm • Coagulation status • Sodium and water retention
Diagnosis
• Signs • Symptoms
Signs
• Hypertension: • Proteinuria (albuminuria): • Oedema:
• Korotkoff I and IV is the reading for systolic and diastolic blood pressure respectively. If you wait the disappearance of the sound to take the diastolic reading (as in nonpregnant state) you may reach down to zero because of the hyperdynamic circulation during pregnancy.
PRE-EXISTING (CHRONIC) HYPERTENSION
Causes •iology. • Secondary to chronic renal disorder: e.g.
– – – – Glomerulonephritis. Hydronephrosis. Pyelonephritis. Renal artery stenosis.
How to measure the blood pressure in pregnancy 2
• The cuff should be applied to the right upper arm with the connecting tubes pointing downwards, the centre of the rubber bag in the cuff is directly over the brachial artery leaving ante-cubital fossa free. • Apply cuff firmly but not tightly around the arm. • Feel the brachial artery and apply the stethoscope directly over it without undue pressure. • Pump up cuff rapidly to 20-30 mmHg above the point at which the pulse sound disappears, and take blood pressure reading without delay.
How to measure the blood pressure in pregnancy 4
Theories
• • • • • • • The uteroplacental bed Immunological factor Genetic factor Renin- angiotensin system Atrial natriuretic peptide (ANP) Prostaglandins Neutrophils
Hypertension
• Blood pressure of 140/90 mmHg or more or an increase of 30 mmHg in systolic and/or 15 mmHg in diastolic blood pressure over the pre- or early pregnancy level.
PRE-ECLAMPSIA
• Incidence: 5-10%. • Aetiology: Although eclampsia had been described since 200 years, no definite aetiology is found for PIH and it is still a disease of theories.
• Causes • Secondary to endocrine disorders: e.g.
– Primary aldosteronism. – Phaeochromocytoma. – Adrenocortical tumours. – Diabetes mellitus.
Effect of Pregnancy on Chronic Hypertension
– – – – – Korotkoff I¾ Appearance of the sound¾ systolic reading. Korotkoff II¾ Accentuation of the sound. Korotkoff III ¾ Sound becomes harsh. Korotkoff IV¾ Sound becomes muffled¾ diastolic reading. Korotkoff V¾ Disappearance of the sound.
Treatment
• • • • • General and medical treatment As pre-eclampsia regarding the following: Rest Antihypertensives Observation
Pregnancy-induced hypertension (PIH):
Pre-existing (chronic) hypertension:
– Hypertension is present before pregnancy, detected in early pregnancy (before 20 weeks in absence of vesicular mole) and postpartum. – Examples:
• essential hypertension, • secondary to chronic renal disorders e.g. pyelonephritis and renal artery stenosis, • coarctation of the aorta, systemic lupus erythematosus and pheochromocytoma.
– Transient hypertension:
• Late onset hypertension, without proteinuria or pathologic oedema
– Pre-eclampsia:
• Hypertension with proteinuria and / or oedema after 20 weeks of pregnancy, but may be earlier in vesicular mole.
How to measure the blood pressure in pregnancy 1
• The patient should rest for at least 30 min. after arriving to the clinic. • Remove any tight clothing from the right arm. • The patient lies comfortably on the left side that her back makes an angle of about 30o with the bed. The right arm is supported to be with the sphygmomanometer at the same level with the patient’s sternum i.e. her heart. Each cm above or below the level of the heart induces a difference of 0.7mmHg in blood pressure reading. She should lie undisturbed in this position for 2-3 min. before blood pressure is measured.
Effect of Chronic Hypertension on Pregnancy
Maternal: • superimposed preeclampsia/ eclampsia in 1520% of cases Foetal: – Intrauterine growth retardation. – Intrauterine foetal death.
Predisposing factors
• • • • • Primigravidae more than multigravidae. Pre-existing hypertension. Previous pre-eclampsia. Family history of pre-eclampsia. Hyperplacentosis i.e. excessive chorionic tissue as in hydatidiform mole, multiple pregnancy, uncontrolled diabetes mellitus and foetal haemolytic diseases. • Obesity. •