Intrapartum Eclampsia

Intrapartum eclampsia is a generalised seizure in a woman with preeclampsia during labour. Labour pain, hypoxia and blood pressure surges lower the seizure threshold. It matters because both mother and fetus are at risk and delivery must be expedited by the quickest safe route.

• Many cases of eclampsia occur in labour.
• Fetal heart rate typically drops and recovers after the seizure.
• Magnesium sulphate prevents repeat seizures.

A woman in labour, often with known or new hypertension, has a tonic clonic seizure, followed by a drowsy postictal state. Contractions may pause and fetal heart changes follow.

• Seizure during a contraction or between contractions.
• Fetal bradycardia lasting 3 to 5 minutes after the seizure.
• Differential diagnosis: epilepsy, cerebral malaria, meningitis, cerebral venous thrombosis, intracranial haemorrhage, hypoglycaemia, amniotic fluid embolism, local anaesthetic toxicity.
• Complications: aspiration, hypoxia, stroke, abruption, pulmonary oedema, HELLP syndrome, postpartum haemorrhage, fetal hypoxia, stillbirth, maternal death.

The diagnosis is clinical, in a woman in labour with hypertension and a seizure.

• Blood pressure, urine protein, temperature, glucose, malaria test.
• Full blood count and film, creatinine, electrolytes, liver enzymes, lactate dehydrogenase, coagulation screen, group and cross-match.
• Continuous fetal heart monitoring; pelvic examination for cervical dilatation, presentation and cord.
• Brain CT or MRI later if focal signs or no recovery.

The principle is maternal stabilisation with magnesium sulphate, blood pressure control and the fastest safe delivery.

• Supportive: left lateral position; protect the airway; oxygen 10 to 15 L/minute; two cannulae; urinary catheter with hourly output; total fluids 80 mL per hour; senior obstetric and anaesthetic review; continuous pulse oximetry.
• Pharmacological: magnesium sulphate 4 g IV over 20 minutes then 1 g per hour for 24 hours after birth, or where infusion is not possible give 4 g IV plus 10 g IM (5 g in each buttock) then 5 g IM 4-hourly; for a repeat seizure give 2 g IV over 5 minutes; stop for absent reflexes, respiratory rate below 12 per minute or urine below 30 mL per hour and give calcium gluconate 1 g IV over 10 minutes for toxicity; diazepam 10 mg IV over 2 minutes only if magnesium is unavailable; labetalol 20 mg IV over 2 minutes then 40 mg, 80 mg and 80 mg at 10 minute intervals (maximum 220 mg) or nifedipine immediate release 10 mg oral repeated once after 30 minutes or hydralazine 5 mg IV then 5 to 10 mg every 20 to 30 minutes (maximum 20 mg); oxytocin infusion 2 mU/minute doubling every 30 minutes to 32 mU/minute if augmentation is needed; oxytocin 10 IU IM after birth and no ergometrine.
• Procedures: delivery within 12 hours of the first seizure; forceps or vacuum delivery if the cervix is fully dilated; caesarean section if birth is not imminent, if there is fetal compromise, or if the cervix is unfavourable; epidural analgesia if platelets are 70 x 10^9/L or more.
• Special groups: kidney disease reduces magnesium sulphate to 0.5 g per hour with level monitoring; asthma uses nifedipine instead of labetalol; previous caesarean scar contraindicates misoprostol.
• Red flags: repeated seizures, coma, blood pressure 160/110 mmHg or more, fetal bradycardia beyond 10 minutes, heavy bleeding, saturation below 94 percent.
• Follow-up: high dependency care for 24 to 48 hours; blood pressure at 6 hours, daily for 5 days, then at 2 and 6 weeks; review at 6 weeks; counsel on recurrence.