Twin Pregnancy with Preeclampsia

Twin pregnancy with preeclampsia is new hypertension of 140/90 mmHg or more after 20 weeks, with proteinuria or organ dysfunction, in a woman carrying twins. Preeclampsia is more frequent than in singleton pregnancies and appears earlier and more severely. It matters because it is a major cause of preterm delivery in twins and of maternal morbidity and death.

• Risk factors: chronic hypertension, diabetes, kidney disease, first pregnancy, obesity, assisted conception, previous preeclampsia.
• Aspirin from 12 weeks and calcium lower the risk.
• Rates are alike in dichorionic and monochorionic twins.

Women often have no symptoms, and the diagnosis is made at antenatal visits. Others have headache, visual change, epigastric pain, swelling and breathlessness. Examination may show hyperreflexia and a large uterus.

• Blood pressure 140/90 mmHg or more with proteinuria.
• Rapid weight gain with oedema.
• Differential diagnosis: gestational hypertension, chronic hypertension, kidney disease, acute fatty liver of pregnancy, HELLP syndrome, normal oedema of twin pregnancy, urinary tract infection.
• Complications: eclampsia, HELLP syndrome, abruption, pulmonary oedema, acute kidney injury, growth restriction, preterm birth, stillbirth, postpartum haemorrhage, maternal death.

The approach is blood pressure and urine protein measurement at every visit.

• Blood pressure on two readings 4 hours apart (or 160/110 mmHg or more once, confirmed in 15 minutes) with urine protein to creatinine ratio 30 mg/mmol or more or organ dysfunction.
• Full blood count, creatinine, liver enzymes, lactate dehydrogenase, uric acid, coagulation screen when platelets are low.
• Ultrasound of both twins for growth, liquor volume and umbilical artery Doppler; cardiotocography of both fetuses.
• Repeat blood tests twice weekly in non-severe disease and every 6 to 12 hours in severe disease.

The principle is blood pressure control, magnesium sulphate for severe features and delivery at 36 to 37 weeks, or earlier for severe disease.

• Supportive: admit for assessment; left lateral rest; blood pressure 4-hourly; daily fetal movement counts; fluid limit of 80 mL per hour when severe; urinary catheter with hourly output; birth in a unit with neonatal intensive care.
• Pharmacological: aspirin 150 mg oral at night from 12 weeks to 36 weeks; calcium 1.5 g elemental oral daily where intake is low; labetalol 200 mg oral every 8 to 12 hours (maximum 2.4 g daily) or nifedipine modified release 30 to 60 mg oral once daily (maximum 120 mg) or methyldopa 250 to 500 mg oral 8-hourly (maximum 3 g daily) aiming for 110 to 135/85 mmHg; 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) for 160/110 mmHg or more; magnesium sulphate 4 g IV over 20 minutes then 1 g per hour for 24 hours for severe features; betamethasone 12 mg IM twice, 24 hours apart, between 24 and 34 weeks and 6 days; oxytocin 10 IU IM at birth, avoiding ergometrine.
• Procedures: delivery at 36 to 37 weeks for non-severe disease and within 24 hours of stabilisation for severe disease; vaginal birth if the first twin is cephalic and induction with misoprostol 25 micrograms vaginal 6-hourly (maximum 4 doses) or Foley catheter; caesarean section for first twin non cephalic or obstetric indications.
• Special groups: kidney disease reduces magnesium sulphate to 0.5 g per hour with level monitoring; asthma uses nifedipine instead of labetalol; platelets below 70 x 10^9/L contraindicate spinal anaesthesia.
• Red flags: blood pressure 160/110 mmHg or more, severe headache, visual change, epigastric pain, seizure, breathlessness, oliguria, platelets below 100 x 10^9/L.
• Follow-up: blood pressure at 6 hours, daily for 5 days, then at 2 and 6 weeks; blood tests daily until normal; review at 6 weeks and aspirin 150 mg oral at night from 12 weeks in the next pregnancy.