Antenatal - Medical conditions and drugs in pregnancy

Question 1

hypothyroidism in pregnancy

Answer 1

untreated/under treated hypothyroidism in pregnancy can lead to miscarriage, anaemia, SGA and pre-eclampsia

hypo treated with levothyroxine which can cross the placenta

dose needs to be increased during pregnancy - by at least 25-50mcg - titrated based on TSH level aiming for low-normal TSH

Question 2

hypertension in pregnancy

Answer 2

medications that need to be stopped:
ACEi, angiotensin receptor blockers, thiazide and thiazide like diuretics

medications that are not known to be harmful: Labetalol, CCBs, alpha-blockers

Question 3

epilepsy in pregnancy

Answer 3

folic acid 5mg daily from before conception

ideally should be controlled by single epileptic drug

SAFE = levetiracetam, lamotrigine, carbamazepine

AVOID = sodium valproate, phenytoin

Question 4

rheumatoid arthritis in pregnancy

Answer 4

well controlled at least 3 months before becoming pregnant

often symptoms improve during pregnancy and may flare after delivery

SAFE = hydroxychloroquine 1st line, sulfasalazine, corticosteroids, (TNF alpha is also safe)

AVOID = methotrexate

Question 5

whats the deal with NSAIDs in pregnancy

Answer 5

avoided unless really necessary - as they block prostaglandins which are important for maintaining the ductus arteriosus in the fetus and neonate

particularly avoided in 3rd trimester as they can cause premature closure of ductus arteriosus and can delay labour

Question 6

beta blockers in pregnancy

Answer 6

labetalol is most frequently used

can cause FGR, hypoglycaemia and bradycardia in neonate,

Question 7

ACEi and angiotensin II receptor blockers

Answer 7

can cross the placenta and enter fetus

affect kidneys in the fetus and reduce production of urine

cause hypocalvaria which is an incomplete formation of the skull

can cause oligohydramnios, miscarriage, fetal death, hypocalvaria, renal failure and hypotension in neonate

Question 8

opiates in pregnancy

Answer 8

cause withdrawal symptoms in neonate after birth causing neonatal abstinence syndrome which presents between 3-72 hours after birth with irritability, tachypnoea, high temp and poor feeding

Question 9

warfarin in pregnancy

Answer 9

avoided in pregnancy

causes fetal loss, congenital malformations, particularly craniofacial problems, bleeding, postpartum haemorrhage, fetal haemorrhage, intracranial bleeding

Question 10

sodium valproate in pregnancy

Answer 10

avoided

causes neural tube defects, developmental delay

valproate pregnancy prevention programme

Question 11

lithium in pregnancy

Answer 11

avoided in pregnancy or those planing pregnancy unless other options have failed

particularly avoided in 1st trimester

when it is used need to monitor closely

avoided in breastfeeding - enters breast milk and is toxic to infant

Question 12

SSRIs in pregnancy

Answer 12

most commonly used antidepressants in pregnancy

can cross the placenta

balance risks and benefits

risk in pregnancy:

• First-trimester - congenital heart defects
• First-trimester use of paroxetine has a stronger link with congenital malformations
• Third-trimester use has a link with persistent pulmonary hypertension in the neonate
• Neonates can experience withdrawal symptoms, usually only mild and not requiring medical management

Question 13

Isotretinoin (roaccutane) in pregnancy

Answer 13

retinoid medication used to treat severe acne

contraindicated in pregnancy - miscarriage and congenital defects

Question 14

rubella in pregnancy

Answer 14

congenital rubella syndrome is caused by maternal infection with rubella virus during 1st 20 weeks

women planning to be pregnant should have MMR vaccine - can be tested for rubella immunity if needed and given 2 doses of MMR 3 months apart

pregnant women cant have MMR vaccine as its live

Question 15

what are some features of congenital rubella syndrome

Answer 15

• Congenital deafness
• Congenital cataracts
• Congenital heart disease (PDA and pulmonary stenosis)
• Learning disability

Question 16

chickenpox in pregnancy

Answer 16

mothers who have previously had chickenpox are immune and safe

women not immune to varicella may be offered the varicella vaccine before/after pregnancy

when not sure about immunity, test VZV IgG levels (positive = safe)

when they are not immune, can be treated with IV varicella immunoglobulins as prophylaxis against developing chickenpox - given within 10 days

when the rash starts - oral aciclovir if they present within 24 hours and >20 weeks gestation

congenital varicella syndrome occurs when infection occurs in first 28 weeks of gestation

Question 17

describe some features of congenital varicella syndrome

Answer 17

• Fetal growth restriction
• Microcephaly, hydrocephalus and learning disability
• Scars and significant skin changes located in specific dermatomes
• Limb hypoplasia (underdeveloped limbs)
• Cataracts and inflammation in the eye (chorioretinitis)

Question 18

listeria in pregnancy

Answer 18

gram-positive bacteria which causes listeriosis

more likely in pregnant women compared with non-pregnant individuals

asymptomatic, flu-like illness or pneumonia or meningoencephalitis

high rate of miscarriage or fetal death

transmitted in unpasteurised dairy products, processed meat and contaminated foods

avoid high risk foods like blue cheese

tx = amoxacillin and gentamicin

Question 19

congenital cytomegalovirus

Answer 19

occurs due to CMV infection in mother during pregnancy

spread through saliva or urine of asymptomatic children

most cases do not cause congenital cytomegalovirus

features - FGR, microcephaly, hearing and vision loss, LD, seizures

Question 20

congenital toxoplasmosis

Answer 20

infection with toxoplasma gondii parasite

usually asymptomatic

primarily spread by contamination with faeces from a cat that is a host

risk higher in later pregnancy

classic triad = intracranial calcification, hydrocephalus, chorioretinitis

Question 21

parvovirus B19 in pregnancy

Answer 21

fifth disease, slapped cheek syndrome, erythema infectiosum

self limiting and usually fades over 1-2 weeks

non-specific viral symptoms followed by a rash 2-5 days later

exposure counts as 15 mins in the same room or face to face contact with someone who has the virus

complications in pregnancy - miscarriage, fetal death, severe fetal anaemia, hydrops fetalis, maternal pre-eclampsia-like syndrome

fetal anaemia is caused by parvovirus infection of the erythroid progenitor cells in the fetal bone marrow and liver - infection causes them to produce faulty blood cells that have shorter life span = less red blood cells results in anaemia = leads to heart failure known as hydrops fetalis

treatment - supportive and refer to fetal medicine to monitor for complications and malformations

Question 22

what is pre-eclampsia-like syndrome (aka mirror syndrome)

Answer 22

rare complication of severe fetal heart failure

triad of hydrops fetalis, placental oedema and oedema in the mother

also features of hypertension and proteinuria

woman suspected of parvovirus infection need tests for IgM, IgG, and rubella antibodies (as a differential)

Question 23

zika in pregnancy

Answer 23

spread by aedes mosquitos and sex with somone who is infected with the virus

no symptoms, minimal symptoms or mild-flu like illness

can lead to congenital zika syndrome in pregnancy - microcephaly, FGR, ventriculomegaly and cerebellar atrophy

pregnant woman who may have contracted the virus should be tested with viral PCR and antibodies to zika virus

refer to fetal medicine for close monitoring

no treatment for virus

Question 24

measles in pregnancy

Answer 24

increased risk of preterm or intrauterine death

passed on during delivery - immunoglobulin infusion around delivery to prevent sub acute sclerosing panencephilitis

Question 25

clostridium perfringes

Answer 25

caused by unsafe abortions

endometritis - sepsis - myglobinurea - aki - death

Question 26

TB in pregnancy

Answer 26

high tb prevalence - give bcg vaccine

keep mother and baby separate till baby has jab

isoniazid infusion until mantoux test is positive

Question 27

GBS

Answer 27

treat with IV benzylpenicillin

for women:

• positive high vaginal swab for GBS
• history of baby with GBS
• bacteruria
• fever
• <37 weeks
• chorioamnitis

Question 28

antipsychotics

Answer 28

increased psychosis risk from possible higher prolactin

clozapine not given in breastfeeding

atypical - oral glucose tolerance testing

depot injections good in pregnancy

Question 29

asthma

Answer 29

avoid LTRAs

less attacks but may be breathless from gravid uterus

Question 30

CF

Answer 30

delivery vaginally

Question 31

SLE

Answer 31

aspirin from positive test to birth