Pregnancy

Question 1

What drugs are contraindicated in pregnancy?

Answer 1

Very few drugs are known to be completely safe in pregnancy. The list below largely comprises of those known to be harmful. Some countries have developed a grading system - see the link.

Antibiotics

• tetracyclines
• aminoglycosides
• sulphonamides and trimethoprim
• quinolones: the BNF advises to avoid due to arthropathy in some animal studies

Other drugs

• ACE inhibitors, angiotensin II receptor antagonists
• statins
• warfarin
• sulfonylureas
• retinoids (including topical)
• cytotoxic agents
• The majority of antiepileptics including valproate, carbamazepine and phenytoin are known to be potentially harmful. The decision to stop such treatments however is difficult as uncontrolled epilepsy is also a risk

Question 2

What is the pharmacological management of hypertension in pregnancy?

Answer 2

• Ensure women are seen by a specialist, however while waiting to see a specialist ensure they are swapped out from taking ACE inhibitors or ARB as these are teratogenic. Instead labetalol is normally used with nifedipine as a second-line agent.
• If the pregnancy is high-risk of developing pre-eclampsia, low dose aspirin is advised.

Question 3

What is the pharmacological management of Eclampsia in pregnancy?

Answer 3

• In eclampsia an IV magnesium sulphate bolus of 4g over 5-10 minutes should be given followed by an infusion of 1g / hour (same as in pre-eclampsia)
• Urine output, reflexes, respiratory rate and oxygen saturations should be monitored during treatment
• Treatment should continue for 24 hours after last seizure or 24 hours after delivery (around 40% of seizures occur post-partum)

Question 4

What is the pharmacological management of epilepsy in pregnancy?

Answer 4

Preconceptual assessment is ideal and involves seizure control with as few drugs as possible at the lowest dose; sodium valproate should be avoided and instead switched to Carbamazepine or Lamotrigine (least teratogenic, but still have risks). This is given together with a higher folic acid dose of 5mg/day which is continued throughout pregnancy.

Question 5

What is the pharmacological management of diabetes in pregnancy?

Answer 5

Management is either metformin or insulin. They should be asked to stop any other drugs they are currently on, and swap to either metformin or insulin.

Question 6

What is the pharmacological management of VTE in pregnancy?

Answer 6

The management involves continuation of LMWH as for non-pregnant. This is safe because it does not cross the placenta. The RCOG recommends once OR twice daily.

• Do NOT convert to warfarin (crosses placenta and may be teratogenic)
• Direct anticoagulants are also contraindicated in pregnancy

Question 7

What is the pharmacological management of hyperthyroidism in pregnancy?

Answer 7

Hypothyroidism is treated with propylthiouracil (PTU) in the first trimester rather than carbimazole.

Question 8

What is the pharmacological management of bipolar affective disorder in pregnancy?

Answer 8

Antipsychotics should be the first-line in pregnant women.

Question 9

What is the pharmacological management of depression in pregnancy?

Answer 9

SSRIs (citalopram) are considered safe during pregnancy. However, there is some evidence of slight increased risk of cardiac malformations in the first trimester and persistent pulmonary hypertension in the third trimester - so patient needs to be counselled on that.