Infections of pregnancy, puerperium and neonate Flashcards
What is the definition of puerperium?
The few weeks following delivery during which the mother’s tissues return to their non-pregnant state (usually 6-8 weeks post partum)
A neonate is an infant less than how many weeks old?
Less than 4
For what 2 reasons do infections during pregnancy warrant special consideration?
1) Some infections during pregnancy are more severe
2) Some infections during pregnancy can affect the foetus
Name 3 infections which during pregnancy tend to be more severe?
1) UTI
2) VZV
3) Entamoeba histolytica
What is the route of transmission of infections from mother to baby during pregnancy?
Haematogenous
Give 6 pathogens which can be transmitted from mother to baby during pregnancy?
1) Cytomegalovirus (CMV)
2) Parovirus B19
3) Toxoplasmosis
4) Syphilis
5) Varicella zoster virus (VZV)
6) Zika virus
Give 6 infections which can be transmitted from mother to baby during delivery?
1) Group B streptococcus
2) Herpes simplex virus (HSV)
3) Gonorrhoea
4) Chlamydia
5) Human immunodeficiency virus
6) Hepatitis B virus
Which 2 infections which can be transmitted from mother to baby during delivery are screened for in pregnancy and prophylactic treatment is given to avoid transmission?
1) HIV
2) Hepatitis B
Other than foetal toxicity for what 2 other reasons may doses of antimicrobials have to be changed during pregnancy?
1) Handling of drugs differs during pregnancy - eg. increase in GFR results in increased renal excretion of many antimicrobials
2) Serum levels of antimicrobials are generally lower during pregnancy
Are pregnant women more at risk of infections?
Yes - physiological and immunological changes during pregnancy pre dispose to some infections
Why is the potential of harm to the foetus/neonate a consideration in the prescribing of any anti microbial during pregnancy? 2
1) All anti microbials cross the placenta to some extent
2) Virtually all antimicrobials appear in breast milk of given in therapeutic amounts to breast feeding women
Which 2 antimicrobials are considered safe in pregnancy?
1) Penicillins
2) Cephalosporins
Which 4 antimicrobials are considered unsafe in pregnancy?
1) Chloramphenicol
2) Tetracycline
3) Fluoroquinolones (eg. ciprofloxacin)
4) Trimethoprim - sulphamethoxazole
Name 2 primary viral infections during pregnancy which cause mild symptoms?
1) CMV
2) Zika virus
What is meant by primary viral infection?
Infection when you are first exposed to the virus with no existing immunity
Name 4 primary viral infections which can be severe during pregnancy?
1) VZV
2) HSV
3) Measles
4) Influenza
Name 2 viruses which are tetratogenic?
1) Rubella virus
2) Zika virus
What is bacteriuria?
Presence of bacteria in the urine
Why is screening for bacteriuria indicated in pregnancy?
Because continuing bacteriuria is associated with premature delivery and increased perinatal mortality
What is the definition of asymptomatic bacteriuria?
No symptoms of UTI and 2 samples containing >10^5 same organism
Why should bacteriuria be treated in pregnancy?
Can develop into symptomatic UTI if untreated
What is the treatment for UTI in pregnancy? 2
1) 7 days relatively non-toxic antibiotic eg. amoxicillin or cephalexin
2) Repeat urine culture post treatment to confirm culture
Can trimethoprim be used in pregnancy?
Avoid in the first trimester but can be given in second and third in conjunction with folate
Intra-amniotic infections are also known by what 2 other terms?
IAI - abbreviation
Chorioamnionitis (refers to inflammation of umbilical cord, amniotic membranes and placenta)
Why are intra-amniotic infections a cause for concern?
They are a major cause of perinatal morbidity and mortality
IAIs affect what percentage of pregnancies with term labour?
1-2%
IAIs affect what percentage of pregnancies with pre-term labour?
20-25%
Name the 5 clinical features of IAIs?
1) maternal fever
2) uterine tenderness
3) malodorous amniotic fluid
4) maternal or foetal tachycardia
5) raised white cell count
Why is prolonged rupture of membranes the most common risk factor for IAIs?
Membranes offer a physical barrier to infections, ruptured membranes allow bacteria to ascend through the cervix
After prolonged rupture of membranes, what are the 4 other risk factors for IAIs?
1) Amniocentesis
2) Cordocentesis
3) Cervical cleavage
4) Multiple vaginal examinations
What is cervical cleavage and why is it a risk factor for IAIs?
Ribbon like structure put into the cervix like a purse string for someone with an incompetent cervix who has suffered multiple miscarriages - as it is a man made structure it increases the risk of infection
Which pathogen can cause IAI by haematogenous infection?
Listeria monocytogenes
What are the 2 pathogeneses of IAIs?
1) Bacteria present in the vagina cause infection by ascending through the cervix
2) Haematogenous infection (although this is rare)
What are the 3 main causative organisms of intra-amniotic infections?
1) Group B streptococcus
2) Enterococci
3) Escherichia coli
What is the management for IAIs?
Antimicrobials and delivery of the foetus
(Anti microbials should be administered at time of infection - although risk of harm from anti-microbial , foetus at greater risk from infection)
What is puerperal endometritis and what percentage of pregnancies does it affect?
Infection of the womb during puerperium, affects around 5% of pregnancies
Is puerperal sepsis still a relevant problem today?
Yes, it remains a major cause of maternal death
What are the 4 risk factors for puerperal endometritis?
1) Caesarean section
2) Prolonged labour
3) Prolonged rupture of membranes
4) Multiple vaginal examinations
What are the 5 clinical features of puerperal endometritis?
1) Fever
2) Uterine tenderness
3) Purulent, foul-smelling lochia (normal discharge after childbirth)
4) Increased white cell count
5) General malaise, abdominal pain
What are the 3 causative organisms of puerperal endometritis?
1) Escherichia coli
2) Beta-haemolytic streptococci
3) Anaerobes
What is the treatment for puerperal endometritis?
Broad spectrum IV anti microbials - continued until the patient has been apyrexial for 48 hours
How is a diagnosis of puerperal endometritis made?
Vaginal endometrial swabs - although the role of these is controversial, in a patient with systemic symptoms a blood culture may be more useful
What is the pathogenesis of puerperal mastitis?
Infection gains access via cracked/fissured nipples
What are the 3 clinical features of puerperal mastitis?
1) Mean onset = 5.5 weeks post delivery
2) Abrupt onset fever, chills and breast soreness
3) Redness, warmth and tenderness of affected breast
What is the most common causative organism of puerperal mastitis?
Staphylococcus aureus
A breast with a blocked duct can present the same as in puerperal mastitis, how can they be distinguished?
Blocked duct - wont be any of the systemic symptoms and will be no purulent discharge from the nipple
How is a diagnosis of puerperal mastitis made? 2
1) Clinical
2) Culture of the pus
What is the management of puerperal mastitis? 4
1) Continue nursing
2) Optomise nursing technique and breast care (also key to prevention)
3) Anti-staphylococci antibiotics (eg. flucoxacillin)
4) Incision/ drainage if abscess present
In addition to puerperal mastitis and puerperal endometritis, what are the 3 other causes of puerperal sepsis?
1) Pneumonia
2) IV catheter related infection
3) Wound infection eg. c section
What is sepsis?
A syndrome resulting from invasion of pathogenic bacteria into the blood
Name a common and serious neonatal complication of neonatal sepsis?
Neonatal meningitis
Depending on the causative organism, neonatal sepsis can be early or late onset, when does early onset infection present?
Within 2 weeks of birth
The clinical features of neonatal sepsis may be subtle and atypical, name 7 possible clinical features of neonatal sepsis?
1) Temperature (hypothermia or pyrexia)
2) Respiratory (dyspnoea, apnoeas, cyanosis)
3) Cardiovascular (tachycardia, bradycardia, hypotension)
4) Hepatic (cardiomegaly, jaundice)
5) GI (anorexia, vomiting, abdominal distension, diarrhoea)
6) Haematological (bleeding disorders)
7) Central nervous system (lethargy, irritability, seizures)
Give the 3 most common causative organisms of neonatal sepsis/ meningitis?
1) Group B streptococcus
2) Escherichia coli
3) Listeria monocytogenes
The latter is not particularly common but is worth remembering
How is a diagnosis of neonatal sepsis/ meningitis made? 3
1) Blood culture
2) Urine culture
3) CSF culture
What is the management of neonatal sepsis/meningitis?
Broad spectrum antimicrobials active against the common causes eg. amoxicillin plus gentamicin
