Hypertensive Disorders in Pregnancy

Clinical Description

Systolic BP greater than 140 mm Hg and Diastolic BP greater than 90 mm Hg on at least two occasions of four hours apart, Hypertensive disorders in pregnancies are major cause of perinatal morbidity and mortality.

Signs and Symptoms

Classification of hypertensive disorders in pregnancy:

Chronic hypertension

Onset before pregnancy or onset at < 20 weeks gestation or persistent

HTN after 12 weeks post-partum, baseline proteinuria may or may not exist.

Gestational

HTN

Onset after 20 weeks gestation and HTN resolves by 12 weeks postnatal, no proteinuria.

Preeclampsia super imposed on chronic hypertension

HTN before pregnancy or onset at <20 weeks gestation or persistent after 12 weeks post-partum plus.

New onset proteinuria or worsening of pre-existing proteinuria

Preeclampsia Gestational hypertension accompanied by one or more of the following new-onset conditions:

Proteinuria

Signs & symptoms of significant end organ dysfunction

Visual disturbance (Photopsia and or scotomata)

Severe headache or persistent headache

Altered mental status

Persistent right upper quadrant pain or epigastric pain unresponsive to analgesia

Thrombocytopenia(< 100 platelets/microL)

Progressive renal insufficiency (serum creatinine >0.9mg/dl or 97.3 micromole/L), acute kidney injury

Pulmonary oedema

Left ventricular failure

Placental insufficiency (oligohydramnios, IUGR, fetal demise)

Eclampsia Preeclampsia plus new-onset, generalized, tonic-clonic seizures or coma

Pharmacological

Management of Gestational hypertension

At the health centre

• If >/=160/110mmHg
• Give Hydralazine 5mg slow IV push over 20 minutes
• or Nifedipine 10mg PO stat
• If </= 160/110mmHg
• Give Methyldopa 500mg PO stat
• Refer to the hospital

At the hospital

• Control blood pressures with methyldopa, Nifedipine or hydralazine to levels of less than 160mmHg systolic and less than 110mmHg
• If blood pressures are still >/= 160/110mmHg after a maximum of 20mg of hydralazine and at the district hospital, discuss with a consultant and refer
• If the blood pressure is still high and at the central hospital, give hydralazine infusion
• Monitor for features of preeclampsia
• Review in high-risk antenatal clinic if stable
• Deliver at 38 weeks 6 days

Management of Pre-eclampsia

At the health Centre

• If >/=160/110mmHg
• Give Hydralazine 5mg slow IV push or nifedipine 10mg po stat
• If </= 160/110mmHg
• Give Methyldopa 500mg po stat
• If patient has severe features start magnesium sulphate
• Give a loading dose of 4g Magnesium Sulphate 20% solution in 500 ml of Normal Saline infused over 10 minutes plus 5 g of Magnesium Sulphate 50% solution in each buttock deep IM with 1 ml of 1% lignocaine
• If only 50% Magnesium sulphate solution is available: mix 8mls of 50% solution of Magnesium sulphate with 12mls of normal saline to make 20%

Magnesium sulphate solution

• If gestational age is less than 34 weeks, give dexamethasone 6mg IM 12 hourly for 48hours
• Refer immediately to the next level of care

At the hospital

• All women with pre-eclampsia should be hospitalized and placed in Labour Ward or HDU for evaluation.
• Blood pressure management as above; If the blood pressure are still high and at the central hospital, give hydralazine infusion
• If the blood pressures are still high, then start labetalol 20mg IV slow push
• Blood pressures should be consistently maintained below 160mmHg systolic and below 110 mmHg diastolic. Avoid lowering BP abruptly. DO NOT GIVE Nifedipine sublingual
• If patient has severe features start magnesium sulphate as at the health Centre
• Monitor urine output, respiratory rate.
• Monitor for signs of Magnesium sulphate toxicity (Absent deep tendon reflex, respiratory rate < 10/ minute, Respiratory distress (oxygen saturations < 92%).
• If convulsion occurs within or after 15 minutes after the loading dose, reload patient by giving 2g MgSO4 in 250 mL of normal saline or ringers lactate given over 20 minute.
• Withhold or delay drug if:
• Respiratory rate falls below 16 per minute.
• Patellar reflexes are absent.
• Urinary output has fallen below 30 mL per hour over the preceding 4 hours.
• In case of respiratory arrest:
• Shout for help
• Assist ventilation with mask and bag.
• Give Calcium Gluconate 1 g (10 mL of 10% solution) in 100ml

N/S IV slowly over 10-20minutes.

• If gestational age is less than 34 weeks, give Dexamethasone 6mg IV 12 hourly for 48hours.
• Do urgent FBC, U & Creatinine, AST & ALT.
• Fetal monitoring in pre-eclampsia should include assessment of fetal biometry, amniotic fluid.
• If pre-eclampsia with severe features deliver immediately through induction of labour and for those with contra-indications to induction of labour perform a caesarean section.
• If pre- eclampsia without severe features, consider delivery at 34-week gestation or earlier if severe features develop.
• If facility has nursery deliver after completion of dexamethasone, if no nursery refer patient to a facility with neonatal care.

Postpartum

• Keep on Magnesium sulphate 24 hours after delivery and continue to monitor BPs.

If still high, keep on Nifedipine.

• Discharge after 48 hours of being stable.
• Review in clinic after one week after discharge.

Management of Eclampsia

• Check circulation, airway, breathing (CAB). Correct hypoxia with oxygen as needed.
• Protect patient from injury (left lateral position in bed with rails or on floor)
• Admit to LW or HDU
• Blood pressure control as described above
• Magnesium Sulphate protocol as described above
• If at the health centre refer immediately
• If at the hospital control blood pressures and seizures and deliver by the quickest method