Infections and Medical Conditions in Pregnancy Flashcards
1
Q
Risks of Infection in Pregnancy
A
Maternal illness can be worse, maternal complications e.g. pre-eclampsia in HIV, preterm labour, vertical transmission, miscarriage, teratogenicity, damage to developing organs e.g. neurological damage.
2
Q
CMV
A
- A herpes virus transmitted by close contact.
- Vertical transmission occurs in 40%.
- 10% of affected neonates are symptomatic - IUGR, pneumonia, thrombocytopenia and hearing, visual or neurological impairment.
- Mx - ultrasound surveillance and fetal blood sampling at 32 weeks for platelet levels helps to determine the risk of sequalae developing.
3
Q
Herpes Simplex
A
- DNA virus responsible for most genital herpes.
- Vertical transmission can occur at delivery especially if vesicles are present. More likely if recent primary maternal infection as no immunity is passed to the fetus.
- Mx - a C section is recommended for those delivering within 6 weeks of primary infection and those with genital vesicles.
4
Q
Rubella
A
- Very rare in the UK due to immunisation.
- Infection in early pregnancy causes deafness, cardiac disease, eye problems and mental retardation. The probability and severity of effects decreases with advancing gestation.
- Mx - TOP if non-immune women develop Rubella before 16 weeks gestation. Screening is routine at booking to identify those in need of vaccination after pregnancy.
5
Q
Toxoplasmosis
A
- Caused by protozoan parasite toxoplasma gondii found in cat faeces, soil or infected meats.
- Effects - infection more common as pregnancy progresses, causes mental retardatioin, convulsions, seizures and visual impairment.
- Diagnosis - IgM testing following exposure.
- Mx - health education reduces infection, spiramycin is started as soon as diagnosis made.
6
Q
Herpes Zoster
A
- Rare (0.05%) but can cause severe maternal illness. Teratogenicity only occurs in 1-2%.
- Most common if delivery occurs within 2 days before or 5 days after maternal symptoms.
- Mx - immunoglobulin is used to prevent and aciclovir used to treat the infection.
7
Q
Parvovirus B19
A
- Causes arthralgia and slapped cheeks in women.
- Effects in fetus - causes anaemia and thrombocytopenia and fetal death in 9%.
- Mx - infected mothers are scanned to look for anaemia and where hydrops is detected in utero transfusion can be administered.
8
Q
Group B streptococcus
A
- Carried by 25% of women - asymptomatic.
- Effects - fetus is infected following ROM and is more likely during preterm or prolonged labour. Group B strep sepsis occurs in 1 in 500 neonates.
- Mx - known GBS carriers and those at high risk are given IV penicillin throughout labour. Screening is with swabs at 34-36 weeks.
9
Q
Hepatitis B
A
- DNA virus transmitted by blood products or sex.
- Infection affects 1% of pregnant women in West.
- Effects - vertical transmission occurs at delivery and 90% of neonates become chronic carriers.
- Mx - neonatal immunisation reduces transmission by 90% and maternal screening is rountine in UK.
10
Q
HIV
A
- Retrovirus that leads to AIDS.
- HIV affects 1% of pregnant women in the UK.
- Effects - increased risk of pre-eclampsia, stillbirth, IUGR and prematurity. Main risk is vertical transmission - commonly occurs beyond 36 weeks, during delivery or breast feeding.
- Mx - infected women should have regular CD4 and viral load tests, prophylaxis against PCP given and HARRT to mother and neonate for 6 weeks, C section and bottle feeding.
11
Q
Syphilis
A
- STI caused by treponema pallidum.
- Active disease in pregnancy can cause miscarriage, congenital disease or stillbirth.
- Benzylpenicillin can be used safely and will prevent but will not reverse any fetal damage.
12
Q
Mycobacterium Tuberculosis
A
- Incidence in the UK is increasing.
- BCG vaccine is live and is contraindicated.
- TB infection causes prematurity, IUGR and maternal mortality in the developing world.
- Treatment is with the normal 1st line meds.
13
Q
Listeriosis
A
- Occurs following ingestion of pate, soft cheeses and prepacked meals - causes non-specific febrile illness in the mother.
- If bacteraemia occurs (0.1%) potentially fatal infection of the fetus may occur.
14
Q
Chlamydia and Gonorrhoea
A
- During pregnancy Chlamydia occurs in 5% and Gonorrhoea occurs in 0.1%,
- Cause preterm labour and neonatal conjunctivitis.
- Mx - azithromycin or erythromycin for Chlamydia and cephalosporins for Gonorrhoea.
15
Q
Bacterial Vaginosis
A
- Overgrowth of normal vaginal lactobilli.
- In some cases causes offensive discharge.
- Effects - preterm labour and miscarriage.
- Mx - Clindamycin.
16
Q
Blood Pressure in Pregnancy
A
- Falls to lowest by 30/15mmHg in second trimester due to decreased vascular resistance.
- Pregnancy induced HTN - when BP rises >140/90 due to transient HTN or pre-eclampsia.
- Pre-existing HTN - when BP is >104/90 before 20 weeks gestation. Increased risk of pre-eclampsia.
17
Q
Pre-eclampsia Definition
A
- Hypertension (>140/90mmHg) and Proteinuria (>0.3g in 24 hours) in 2nd half of pregnancy. It is placental in origin and cured by delivery.
- Affects 6% of nulliparous women and is less common in multiparous women.
18
Q
Pre-eclampsia - Risk Factors
A
Nulliparity, personal or family hx, older maternal age, chronic hypertension, diabetes, twin pregnancy, AI disease, renal disease or obesity.
19
Q
Pre-eclampsia - Clinical Features
A
- Hx - usually asymptomatic but headache, visual disturbance, N+V or epigastric pain can occur.
- Examination - oedema and tender epigastrum.
20
Q
Pre-eclampsia - Maternal Complications
A
- Eclampsia - seizures due to cerebrovascular spasm occurs 0.05%. Mx - magnesium sulphate.
- Cerebrovascular haemorrhage - results from failure of blood flow auto-regulation.
- HELLP syndrome - haemolysis, elevated liver enzymes and low platelet count.
- Renal failure - can require haemodialysis.
- Pulmonary oedema - due to fluid overload.
21
Q
Pre-eclampsia - Fetal Complications
A
- If occuring between 36 weeks the principle problem is IUGR and in some cases iatrogenic pre-term delivery is required.
- Also increased risk of placental abruption.
22
Q
Pre-eclampsia - Investigations
A
- Dx - 24 hour protein or protein/creatinine ratio.
- To monitor mother - blood tests for Hb, platelets and LFTs to detect impending HELLP.
- To monitor fetus - USS for growth and CTG.
- Screening - all pregnant women have regular BP monitoring and urinalysis checks.
23
Q
Pre-eclampsia - Mx
A
- Antihypertensives e.g. Nifidipine or Labetolol.
- IV magnesium sulphate to prevent eclampsia.
- Steroids - if gestation is <34 weeks.
- Delivery can be indicated if gestation >36 wks.
- Post-natal care - it can take up to 24 hours for severe disease to resolve. LFTs, platelet levels and fluid monitoring should continue and BP should be maintained <140/90mmHg.
24
Q
Gestational Diabetes
A
- Glucose intolerance during pregnancy that resolves following delivery. Diagnosis is by 75g glucose load leading to levels >9 mmol/L.
- Affects 2% of pregnant women
- In addition pre-existing diabetes affects 0.1-0.3% of pregnancy women and they will require increased levels of insulin during pregnancy.
25
Q
Gestational Diabetes - Risk Factors
A
Hx of gestational DM, FH of diabetes, a fetus >4kg, previous stillbirth, weight >100kg or PCOS.
26
Q
Gestational DM - Maternal Complications
A
- Increased insulin requirements and aiming for optimum control can result in hypoglycaemia.
- Increased risk of infection e.g UTI, endometrial or wound infections and pre-eclampsia.
- Large fetus results in increased likelihood of instrumental or C section delivery.
- Retinopathy is often worsened by pregnancy.
27
Q
Gestational DM - Fetal Complications
A
- Congenital abnormalities (e.g. neural tube or cardiac defects) are 3-4 times more common.
- Preterm labour occurs in 10%.
- Fetal lung maturity is decreased.
- Large fetus can lead to shoulder dystocia, birth trauma, fetal compromise or distress.
28
Q
Gestational DM - Management
A
- High fibre, low carb diet and monitor glucose.
- If preprandial glucose levels are consistently >6mmol/L start insulin therapy - usually long acting at night and 3 x short acting doses.
- Aim to maintain BMs between 4-6 mmol/L.
29
Q
Gestational DM - The Delivery
A
- Normally arranged for 39 weeks if glucose control has been good. If estimated fetal weight exceeds 4kg elective C section is indicated.
- After delivery the neonate commonly develops hypoglycaemia as insulin levels are high. Respiratory distress syndrome is more common.
30
Q
Gestational DM - The Puerperium
A
- In pre-existing diabetics insulin doses should quickly be returned to pre-pregnancy levels.
- In gestational diabetics insulin should be stopped.
- A glucose tolerance test is performed after 3 months -50% will develop T2DM within 10 yrs.
31
Q
The Rhesus System
A
- Consists of 3 gene pairs - Cc, Dd and Ee.
- Individuals who inherit DD or Dd are said to be Rhesus D positive.
- Individuals with other alleles (even dd) recognise the D allele as foreign if exposed.
32
Q
Sensitisation
A
Delivery, placental abruption and amniocentesis encourage fetal RBCs to enter maternal circulation. If the fetus is D positive the mother will mount an immune response (sensitisation) and produce anti-D antibodies. If the mother is exposed to anti-D in the future a large immune response will occur.
33
Q
Rhesus Haemolytic Disease
A
- Anti-D antibodies produced by the mother can cross the placenta and bind to fetal RBCs.
- This causes them to be destroyed by the reticulo-endothelial system = haemolytic anaemia.
34
Q
Anti-D
A
- Exogenous anti-D mops up fetal red blood cells preventing the mothers immune response.
- Anti-D is given to all rhesus negative women at 28 and 36 weeks and after a potentially sensitising event e.g. bleeding and after delivery if the fetus is found to be rhesus D positive.
