Drugs in pregnancy and breastfeeding, and postnatal contraception

Question 1

What broad drug classes should be avoided in pregnancy?

Answer 1

BOWS - NAILS - TAN - CAT
Beta-blockers, Opiates, Warfarin, Sodium valproate
NSAIDs, ACEis, Isotretinoin, Lithium, SSRIs
Trimethoprim (1/3), ARBs, Nitrofurantoin (term)
Co-amoxiclav, Tetracyclines

Question 2

What effects do beta-blockers have in pregnancy?

Answer 2

-IUGR
-Neonatal hypoglycaemia
-Neonatal bradycardia

Question 3

What effects can opiates cause?

Answer 3

-NAS - irritability, tachypnoea, high temperature, poor feeding
-Generally can be considered safe

Question 4

What effects can warfarin cause?

Answer 4

-Crosses placenta and is teratogenic
-Stillbirth / miscarriage
-Congenital malformations especially craniofacial
-APH, PPH, foetal haemorrhage, intracranial bleeding

Question 5

What effects can sodium valproate cause?

Answer 5

-Neural tube defects
-Developmental delay

Question 6

What effects can NSAIDs cause?

Answer 6

-Block prostaglandins so can cause premature closure of the DUCTUS ARTERIOSUS
-Can also DELAY LABOUR due to blocking of uterine contractions and cervical ripening

Question 7

What effects can ACEis and ARBs cause?

Answer 7

-Cross the placenta
-Affect the kidneys leading to reducing urine production by the foetus –> OLIGOHYDRAMNIOS
-HYPOCALVARIA (reduced bone formation)
-Miscarriage / skill birth
-Neonatal renal failure and hypotension

Question 8

What effects can Isotretinoin cause?

Answer 8

-Teroatogenic
-Miscarriage

Question 9

What effects can lithium cause?

Answer 9

-Congenital heart defects especially EBSTEIN’S ANOMALY (tricuspid valve leaflet on the right side is set lower than it should be –> large RA, small RV)

Question 10

What effects can SSRIs cause?

Answer 10

FIRST TRIMESTER
-Congenital heart defects
-Congenital malformations especially with paroxetine
THIRD TRIMESTER
-Neonatal persistent pulmonary hypertension
-Withdrawal in the neonate

Question 11

What effects can trimethoprim cause?

Answer 11

-Folic acid antagonist
-Neural tube defects
-Cleft lip / palate
-Congenital heart defects

Question 12

What effects can nitrofurantoin cause?

Answer 12

-Avoided at term
-Neonatal haemolytic disease

Question 13

What effects can co-amoxiclav cause?

Answer 13

-Risk of NEC in the baby

Question 14

What effects can tetracyclines cause?

Answer 14

-Neonatal tooth discolouration

Question 15

What common drugs are contraindicated in breastfeeding?

Answer 15

-Warfarin
-Lithium

Question 16

When is contraception needed from after birth?

Answer 16

After 3 weeks (earliest ovulation occurs 28 days after birth)

Question 17

When can the POP / depo provera be started after birth?

Answer 17

Immediately

Question 18

When can the COCP (+ring, patch) be started after birth?

Answer 18

-After 3 weeks if not breastfeeding
-After 6 weeks if breastfeeding

Question 19

When can the implant be fitted after birth?

Answer 19

-Immediately

Question 20

When can IUS / Cu-IUD be fitted after birth?

Answer 20

-Either immediately (within 48h) after birth / C-section
OR
-4 weeks postpartum

Question 21

When can emergency contraception be used after birth?

Answer 21

-Ullipristal / levonorgestrel after 21 days
-Cu-IUD after 28 days

Question 22

Under what circumstances is lactational amenorrhoea an effective method of contraception?

Answer 22

-Exclusively breastfeeding
-<6 months postpartum
-Feeding every 4h
-Amenorrhoeic