15 - Medications and Infections in Pregnancy Flashcards
What happens to hypothyroidism in pregnancy?
Levothyroxine dose needs to be increased by around 25-50mcg, titrated based on TSH levels aiming for low to normal
Levothyroxine can cross placenta to get to baby
Undertreated hypothyroidism: anaemia, miscarriage, SGA, pre-eclampsia
How should you manage a hypertensive woman who is on medication and then becomes pregnant?
STOP
- ACEis e.g ramipril
- ARB e.g Losartan
- Thiazides e.g Indapamide
They can cause congenital abnormalities
If a woman with epilepsy becomes pregnant, how does her epilepsy management change?
Before conception: 5mg folic acid daily, switch to single AED
AED: Lamotrigine, Carbamazepine, Levetiracetam
When pregnant seizure control is worse due to added stress, lack of sleep and changes to medication. Seizures do not harm baby bar physical injury
How may the treatment regime in a woman with RA be altered if she becomes pregnant?
Ideally should have good symptom control for 3/12 before getting pregnant
Symptoms of RA will get better during pregnancy and may flare after delivery
What are the issues with using the following drugs during pregnancy:
- NSAIDs
- B-Blockers
- ACEi/ARB
NSAIDs
- Need to be avoided as they inhibit prostaglandins
- Only used in RA
- Can cause premature closure of ductus arteriosus and can delay labour
B-Blockers
- Only use labetalol
- Can cause FGR, hypoglycaemia in the neonate, bradycardia in the neonate
ACEi/ARB
- Affects fetal kidneys so oligohydramnios
- Hypocalvaria
- Miscarriage
- Renal failure in the neonate
- Hypotension in the neonate
What are the issues with using the following drugs during pregnancy:
- Opiates
- Warfarin
- Sodium Valproate
Opiates
- Neonatal Abstinence Syndrome: withdrawal 3-72 hours after delivery, baby has irritability/poor feeding, tachypnea, high temp
Warfarin
- Crosses placenta and is teratogenic
- Can cause fetal loss, craniofacial abnormalities, PPH, fetal haemorraghe, intrapartum bleeding
Sodium Valproate
- Neural tube defects and developmental delay
- Should be on pregnancy prevention programme if on this
What are the issues with using the following drugs during pregnancy:
- Lithium
- SSRIs
- Isotretinoin (Roaccutane)
Lithium
- Avoided especially in first trimester as congenital cardiac abnormalities e.g Ebstein’s anomaly
- If need to take it should monitor every 4 weeks then every week from 36 weeks
- Can get in breast milk and is toxic so avoid breastfeeding
SSRIs
- Risks vs Benefits
- If used in first trimester risk of congenital cardiac abnormalities, especially Paroxetine
- If used in third trimester risk of persistent pulmonary hypertension in neonate
- Neonate can have withdrawals but usually mild
Isotretinoin
- Highly teratogenic can cause miscarriage and congenital abnormalities
- Reliable contraception before, during and for one month after use
What is congenital rubella syndrome and how can it be avoided?
When a pregnant woman becomes infected with Rubella before 20 weeks gestation. Worse if before 10 weeks
German Measles
If planning to become pregnant check MMR vaccines, if doubt do antibody tests then if negative vaccinate with two doses three months apart
DO NOT VACCINATE DURING PREGNANCY AS LIVE VACCINE!! Get after birth
What are the features of congenital rubella syndrome?
Mother is often asymptomatic. If she has symptoms often malaise, headache, maculopapular rash
- Congenital deafness
- Congenital cataracts
- Congenital heart disease (PDA and pulmonary stenosis)
- Learning disability
- Microencephaly
- Blueberry muffin rash
- Late onset: DM, Thyroiditis, GH abnormalities, behavioural disorders
How is congenital rubella syndrome managed?
Luckily very rare due to mass MMR vaccination
Mother: No treatment, Antipyretics, Inform her she is infective from 7 days prior to onset of symptoms to 4 days after
Neonate: see image, if over 20 weeks no issue
What are the issues with chickenpox during pregnancy?
VSV can cause in
- Mother: varicella pneumonitis, hepatitis or encephalitis
- Baby: Fetal Varicella Syndrome, Severe Neonatal Varicella infection if infected near time of delivery
How do you manage a woman who is pregnant who has had varicella contact?
- Previous chickenpox: no management needed
- If no previous chickenpox: Test IgG, if negative need IV VZIG within 10 days of contact before rash occurs. Infectious for 8-28 days
How do you manage a woman that is pregnant who has chicken pox?
- Aciclovir PO if presents within 24 hours of rash and >20 weeks gestation
- Counsel about symptoms of pneumonia and haematological rash and tell them to return if have this
- Refer for serial US scans 5 weeks post infection to look for
- Consider vaccine AFTER pregnancy
How is Varicella of the Newborn managed?
Occurs if infection in last 4 weeks of pregnancy
Transfers via placenta, vagina or contact
Management: VZIG +/- Aciclovir
What are some symptoms of fetal varicella syndrome?
Only occurs if infection was before 20 weeks gestation
- Fetal growth restriction
- Microcephaly, hydrocephalus and learning disability
- Skin scarring in dermatomal pattern
- Limb hypoplasia
- Eyes: Cataracts, Chorioretinitis, Micropthalmia
What is listeria and why is it dangerous in pregnancy?
Gram positive bacteria from unpasteurised dairy e.g blue cheese, and processed meats. Avoid these and practice good food hygeine
Infection in mother may be asymptomatic, cause a flu-like illness, or pneumonia, meningoencephalitis
Listeriosis in pregnant women has a high rate of miscarriage or fetal death. It can also cause severe neonatal infection.
How is CMV transmitted to a pregnant woman?
Often through urine or saliva of asymptomatic child
Around 1 in 100 women will get this infection, ⅓ will pass it to the fetus and then 5% of those will have damage from the virus
Risk of damage to fetus highest in first trimester
How is CMV in a pregnant woman investigated and managed?
Ix
- IgG and IgM serology
- If IgM then recent infection
Management
All women should be referred to fetal medicine specialist
Mother: No treatment as aciclovir/ganaclovir etc can be teratogenic
Fetus: Aminocentesis and PCR of fluid for virus after 21 weeks gestation. If +ve offer termination, if does not want then serial US to assess for manifestations of CMV
What issues can congenital cytomegalovirus cause?
- Fetal growth restriction
- Microcephaly
- Hearing loss
- Vision loss
- Learning disability
- Seizures
20-30% mortality due to DIC, hepatic dysfunction or bacterial superinfection
What is congenital toxoplasmosis caused by?
Toxoplasma Gondii parasite that is found in cat faeces
How does congenital toxoplasmosis present?
Classic Triad:
- Intracranial calcification
- Hydrocephalus
- Chorioretinitis
How is congenital toxoplasmosis diagnosed and managed?
Dx: Aminocentesis and test Maternal IgM
Mx: Spiramycin antibiotic
How does parvovirus B-19 present in children and non-pregnant adults?
Slapped Cheek Syndrome/Erythema Infectiosum
Starts with non-specific viral symptoms then after 2 – 5 days diffuse bright red rash on both cheeks
A few days later a reticular mildly erythematous rash affecting the trunk and limbs appears, which can be raised and itchy
Infectious 7-10 days before rash appears
What are the issues with Parvovirus B19 infections during pregnancy?
- Miscarriage or fetal death
- Severe fetal anaemia
- Hydrops fetalis (fetal heart failure)
- Maternal pre-eclampsia-like syndrome
What is maternal pre-eclampsia-like syndrome/Mirror syndrome and why does it occur?
Complication of hydrops fetalis
Triad of: hydrops fetalis, placental oedema and oedema in the mother. Also hypertension and proteinuria
Why may hydrops fetalis occur during pregnancy after infection with Parvovirus B19?
Parvovirus infection of erythroid progenitor cells in the fetal bone marrow and liver that produce RBCs
Faulty RBCs means shorter life span so anaemia. Anaemia leads to heart failure
If a pregnant woman is suspected to have been infected/in contact with Parvovirus B19, how is this diagnosed and managed?
Dx: Check IgM and IgG to PVB19, Rubella antibodies
Mx
Refer to fetal medicine specialist to monitor for malformations and complications
Serial US 4 weeks post infection, then repeat every 1-2 weeks until 30 weeks
If evidence of fetal hydrops on US, refer to tertiary centre for intrauterine erythrocyte transfusion
What are some signs of fetal hydrops on ultrasound?
- Ascites
- Subcutaneous oedema
- Pleural effusion
- Pericardial effusion
- Scalp oedema
- Polyhydramnios
What is congenital Zika syndrome?
Spread by Aedes mosquito or sex with infected person
- Microcephaly
- Fetal growth restriction
- Other intracranial abnormalities: e.g ventriculomegaly and cerebellar atrophy
Is GBS screened for in pregnancy?
Not screened for unless high risk as not all women who screen positive are positive at delivery so unnecessary treatment
High risk: symptoms of UTI or chorioamnitis in pregnancy, those with STI symptoms previously, previous baby with GBS
How is a GBS infection managed to prevent it passing to the newborn?
High dose IV benzylpenicillin during labour and delivery
Not indicated to give abx if planned C-Section as it is the rupture of membranes that exposes baby to GBS
How do lower UTIs and pyelonephritis present?
How is an antepartum haemorraghe managed?
(NB)
- Check for haemodynamic compromise and if so resus
- Take history and perform abdo and speculum exam. DO NOT DO PELVIC EXAM IN CASE PLACENTA PRAEVIA
3. Perform CTG and US to look for placenta praevia
- Gain IV access and take bloods (FBC, G+S and Crossmatch, Coag Screen, U+E, LFT, Kleihauer test if Rh-ve)
- Consider steroids for fetal lung maturation if likely to deliver
What women need postnatal thromboprophylaxis and for how long?
Four or more risk factors
Need for 6 weeks
Perform individual risk assessment form
What is chorioamnionitis and how does it present?
Infection of the membranes in the uterus
- Fever
- Abdo pain
- Offensive vaginal discharge
- Evidence of ROM
- Fetal tachycardia
- Uterine tenderness
How is chorioamnionitis managed?
Treated as maternal sepsis - ADMISSION AND DELIVERY
Give Cefuroxime + Metronidazole IV and continue for 5 days
What is haemolytic disease of the newborn and why is it an issue?
When a rhesus -ve mother becomes sensitised to her rhesus +ve child and produces antibodies that can cross the placenta
This could be due to childbirth, obstetric procedure, bleeding
Can lead to Hydrops Fetalis and Kernicterus
What are some of the pre and post delivery features of haemolytic disease of the newborn?
Pre-delivery
- Hydrops foetalis: foetal oedema in at least two compartments (e.g pericardial effusion, pleural effusion, ascites)
- Yellow coloured amniotic fluid
Post-delivery
- Jaundice and kernicterus
- Foetal anaemia causing skin pallor
- Hepatomegaly or splenomegaly
- Severe oedema if hydrops foetalis was present in utero
What is foetal blood sampling and when should you/shouldn’t you do it?
- Done during labour when there is a suspicious CTG to confirm if fetal hypoxia
- Make small incision on fetal scalp transvaginally then collect blood and look for acidaemia
- DO NOT do during or immediately after a prolonger deceleration
What is a TORCH screen and when is it performed?
Screen for infections when there is IUGR, Intrauterine Death and Suspected congenital infection
May be taken from mother or from baby after birth
What is the issue with catching influenza during pregnancy?
- Complications like bronchitis and pneumonia
- Premature delivery
- Low birthweight
- Stillbirth
What issues can syphilis cause in pregnancy?
- Spontaneous abortion
- Stillbirth
- Hydrops
- Intrauterine growth restriction
- Liveborn infected children
If a pregnant woman screens positive for Hep B on her booking bloods, what action needs to be taken?
- Test partner and other children for infection and give them vaccines
- Baby will need immediate vaccine and 5 follow up vaccines after birth. This is to stop them getting chronic liver disease
If a woman is HIV positive and planning to have a baby what advice should she be given?
Sperm washing may not be best option if male viral load is low
If a woman is HIV positive, what measures can be taken to reduce the risk of vertical transmission to the baby?
- ART to keep viral load low
- C-Section
- Avoid breast feeding
- Give baby Zidovudine within 4 hours of birth for first 4-6 weeks of life. Test baby 2 days after birth, 6 weeks, 12 weeks, 18 months
Reduces chances of transmission from 1 in 4 to 1 in 100
If a woman is having variable decelerations on her CTG, what measures can be done to try and correct these?
- Lie her on her side
- Give fluids
If there is a prolonged fetal bradycardia over 3 minutes what needs to be done?
CAT 1 C SECTION DELIVER BABY WITHIN NEXT 9 MINUTES (12 MINUTES TOTAL)
