8.6 Medications in Pregnancy

Question 1

What do NSAIDs block in their MOA?

Answer 1

They block prostaglandins

Question 2

What do prostaglandins do in obstetrics?

Answer 2

• maintain the ductus arteriosus patent
• soften the cervix
• stimulate uterine contractions

Question 3

Can NSAIDS be used in pregnancy?

Answer 3

Generally avoided unless necessary eg RA

Avoid in third trimester as can cause premature closure of ductus arteriosus (by blocking prostaglandins).

They can delay labour (blocking prostaglandins so delay cervix softening and delay contractions).

Question 4

What is first line for high BP in pre-eclampsia?

Answer 4

Labetalol

Question 5

What adverse effects can beta-blockers cause?

Answer 5

• fetal growth restriction
• hypoglycaemia in neonate
• bradycardia in the neonate

Question 6

What do ACEi and ARBs cause in pregnancy?

Answer 6

• oligohydramnios
• hypocalveria (incomplete skull bones)
• miscarriage / death
• renal failure in neonate
• hypotension neonate

Question 7

How does neonatal abstinence syndrome present?

Answer 7

Between 3-72hrs post birth

• irritability
• tachypnoea
• high temp
• poor feeding

(from opiate use in mother)

Question 8

What effect can warfarin have in pregnancy?

Answer 8

AVOID

• fetal loss
• craniofacial malformations
• bleeding and haemorrhage in foetus, intracranial, or postpartum in mum

Question 9

Which epilepsy drugs should be avoided in pregnancy?

Answer 9

Sodium Valproate AVOID (NTD + development)

Phenytoin AVOID (cleft lip and palate)

Question 10

Normally what is lithium used for?

Answer 10

Patients with bipolar disorder, mania, recurrent depression.

Question 11

What happens if lithium is used in pregnancy?

Answer 11

Ebstein’s anomaly
(and other congenital cardiac abnormalities)
Particularly in the first trimester.

Question 12

What is Ebsteins anomaly?

Answer 12

Tricuspid valve is set lower on the right side of the heart –> bigger right atrium and smaller RV.

Question 13

When might lithium be used in pregnancy?

Answer 13

Avoided unless other antipsychotic have failed.

Levels are monitored every 4 weeks and weekly from week 36.

Question 14

Can lithium be used when breastfeeding?

Answer 14

No. Lithium enters the breastmilk so breastfeeding must stop.

Question 15

What antidepressants are most commonly used in pregnancy?

Answer 15

SSRIs

can cross the placenta, benefits must outweigh the risks

Question 16

What are the risks of SSRIs in the first trimester?

Answer 16

Congenital heart defects.

Paroxetine especially has risk of congenital malformations in 1st trimester.

Question 17

What are the risk of SSRIs in the 3rd trimester and beyond?

Answer 17

Persistent pulmonary hypertension in neonate and
 Withdrawal symptoms (mild).

Question 18

What do women taking isotretinoin (roaccutane) need?

Answer 18

Very reliable contraception. (during and for one month after)

Teratogenic, miscarriage and congenital defects. (similar to vit A)