(49) Infections of pregnancy, puerperium and neonate Flashcards
What is puerperium?
The puerperal state - the few weeks following delivery during which the mother’s tissues return to their non-pregnant state (usually 6-8 weeks postpartum)
What is a neonate?
A recently born individual; specifically an infant less than four weeks old
Why do infections in pregnancy warrant special consideration?
- some infections are more severe or more common in pregnancy eg. UTI, VZV, entamoeba histolytic
- some infections can affect the foetus
What are the main 2 ways that infection can be spread from the mother to baby?
- haematogenous (via placenta)
- during delivery
Name 6 pathogens that can spread to foetus by haemaotgenous spread
- CMV
- parovirus B19
- toxoplasmosis
- syphilis
- VZV
- zika virus
How does the mother acquire CMV, parovirus B19, VZV?
Respiratory droplets/secretions (requires reasonably close proximity)
How does the mother acquire toxoplasmosis?
Ingestion of oocysts from the parasite
How does the mother acquire syphilis?
Sexual transmission
How does the mother acquire zika virus?
Mosquito bite
Name 6 pathogens that can be transmitted from mother to baby during delivery
- group B streptococcus
- HSV
- gonorrhoea
- chlamydia
- HIV
- hep B
What actions are taken against HIV and Hep B during pregnancy?
Prophylaxis is available and screening is undertaken in pregnancy
Which bacteria may be harmful to baby but may be part of normal vaginal flora?
Group B streptococcus - mother offered prophylaxis if they have group b strep to prevent transmission
Since mucosal contact is needed for gonorrhoea transmission, what part of the baby is vulnerable?
The baby’s eyes - causes conjunctivitis
How is antimicrobial prescribing affected in pregnancy?
- handling of drugs differs during pregnancy eg. increased GFR = increased renal excretion of many antimicrobials
- serum levels of antimicrobials are generally lower during pregnancy
Since there is an increased glomerular filtration rate during pregnancy, what is there a risk of?
Under-dosing of antibiotics/ treatment failure through under-dosing
What must be considered when prescribing antimicrobials during pregnancy?
The potential to cause harm to the embryo/foetus/neonate
Why might prescribing antimicrobials to the mother affect the foetus?
- all antimicrobials cross the placenta to some extent
- virtually all antimicrobials appear in breast milk if given in therapeutic amounts to breast feeding women
Which 2 types of antibiotics are considered “safe” during pregnancy?
- penicillins
- cephalosporins
Which 4 types of antibiotics are considered unsafe during pregnancy?
- chloramphenicol
- tetracycline
- fluoroquinolones eg. ciprofloxacin
- trimethoprim-sulphamethoxazole
Is there ever a need to use “unsafe” antibiotics during the pregnancy?
Only when there is a severe need to eg. severe sepsis of the mother
Give 2 primary viral infections that cause mild symptoms or are asymptomatic during pregnancy
- CMV
- Zika
Give 4 primary viral infections that are more severe during pregnancy?
- VZV
- HSV
- measles
- influenza
Some viruses are teratogenic. Give 2 examples
- rubella
- Zika virus?
What does diagnosis of viral infection during pregnancy involve?
Serology and/or PCR of relevant samples
- blood
- vesicle fluid
- amniotic fluid
How is asymptomatic bacteriuria defined?
No symptoms of UTI but 2 samples containing >10^5 of the same organism confirmed - treat even though asymptomatic
Why is asymptomatic dangerous and must be treated?
Bacteriuria can develop into symptomatic UTI if untreated - continuing bacteriuria is associated with premature delivery and increased perinatal mortality
Sime UTIs are common in pregnancy, what test is indicated in pregnancy?
Screening for bacteriuria
What is the typical treatment for UTI?
- 7 days of relatively non-toxic antibiotic eg. amoxicillin or cefalexin (trimethoprim)
- repeat urine culture post-treatment to confirm cure
Cefalexin (trimethoprim) is sometimes used to treat UTI during pregnancy but what is advised?
Avoid use in the first trimester
Give with folate (as it is a folate antagonist so can cause neural tube defects)
How common are intra-amnitoic infections?
Affects 1-2% term pregnancies
How many pre-term labour pregnancies are affected by intra-amnitoic infections?
20-25%
Intra-amniotic infections are a major cause of what?
Perinatal morbidity and mortality
What is chorioamnionitis?
Inflammation of the umbilical cord, amniotic membranes and placenta
What are the clinical features of intra-amniotic infections?
- sustained maternal fever
- uterine tenderness
- malodorous amniotic fluid
- maternal or foetal tachycardia (sign of systemic illness)
- raised white cell count
What are the risk factors for intra-amniotic infections?
- prolonged rupture of membranes
- amniocentesis, cordocentesis, cervical cerclage, multiple vaginal examinations
- bacterial vaginosis?
What are the 3 main mechanisms of pathogenesis for intra-amniotic infections?
- bacteria in vagina ascending through cervix
- direct inoculation (by procedures etc)
- haematogenous (rare, eg. listeria monocytogenes)
What is cervical cerclage?
Stitches used to close the cervix during pregnancy to help prevent pregnancy loss or premature birth (give when recurrent miscarriages)
What are the 3 main causative organisms of intra-amniotic infections?
- group B streptococcus
- enterococci
- escherichia coli
Enterococci and escherichia coli may cause intra-amnitoic infections, but where is their normal habitat?
Gastrointestinal tract (GIT)
How are intra-amniotic infections managed?
- antimicrobials and delivery of foetus as soon as possible
- antimicrobials should be administered at the time of diagnosis (not after delivery)
What is puerperal endometritis?
Infection of the uterus during puerperium
How many pregnancies does puerperal endometritis affect?
Around 5% of pregnancies
Puerperal sepsis is a major cause of what?
Maternal death
What are the risk factors for puerperal endometritis?
- caesarean section
- prolonged labour
- prolonged rupture of membranes
- multiple vaginal examinations
What are the clinical features of puerperal endometritis?
- fever
- uterine tenderness
- purulent, foul-smelling lochia
- increased white cell count
- general malaise, abdominal pain
What is lochia?
The vaginal discharge after giving birth (puerperium) containing blood, mucus, and uterine tissue
What defines ‘fever’ in puerperal endometritis?
38.5 in first 24h post delivery OR over 38 for 4 hours, 24h+ after delivery
What are the 3 main causative organisms of puerperal endometritis?
- escherichia coli
- beta-haemolytic streptococci
- anaerobes
key organism = group A strep
Why is role of transvaginal endometrial swabs in diagnosis of endometritis controversial?
Microbiological diagnosis not very useful as you will get vaginal flora so unsure as to what is going on in the uterus (blood culture more useful)
How is puerperal endometritis treated?
Usually caused by mixed organisms so use broad-spectrum intravenous antimicrobials - continue until patient has been apyrexial for 48 hours
Co-amoxiclax is a suitable antibiotic for puerperal endometritis. What does it contain?
Amoxicillin and clavulanic acid
How does infection gain access to the breast tissue in puerperal mastitis?
Through cracked/fissured nipples
Puerperal mastitis may be confused with which other condition?
Blocked milk ducts (also red and sore but shouldn’t have general malaise and fever)
Describe the clinical features of puerperal mastitis?
- mean onset = 5.5 weeks post delivery
- abrupt onset of fever, chills and breast soreness
- redness, warmth and tenderness of affected breast
How are rigours described?
Sequence of cold and shivering and then hot and sweaty - almost always caused by infection
What is the predominant causative organism in puerperal mastitis?
Staphylococcus aureus
Does puerperal mastitis occur in breast feeding or non-breast feeding mothers?
Usually in breast feeding mothers but not necessarily - don’t stop breast feeding though!
How is puerperal mastitis diagnosed?
- clinical
- culture of pus
How is puerperal mastitis managed?
- continue nursing
- optimise nursing technique and breast care (also key to prevention)
- anti-staphylococcus antibiotics eg. flucloxacillin
- incision/drainage if abscess present
Which antibiotic should be used in puerperal mastitis?
Flucloxacillin
Why should abscesses be drained before use of antibiotics?
Antibiotics don’t tend to work if there is pus present
Give 3 other causes of puerperal sepsis
- pneumonia
- intravenous catheter-related infection
- wound infection eg. C-section
What is neonatal sepsis?
A syndrome resulting from invasion of pathogenic bacteria into the blood
What is a common complication of neonatal sepsis?
Neonatal meningitis
“early onset” infection present within how many weeks of birth?
Within 2 weeks of birth
Signs of neonatal sepsis/meningitis may be what?
Subtle/atypical eg. not feeding, diarrhoea etc
What are the temperature symptoms of neonatal sepsis/meningitis?
hypothermia or pyrexia
What are the respiratory symptoms of neonatal sepsis/meningitis?
- dyspnoea
- apnoeas
- cyanosis
What are the cardiovascular symptoms of neonatal sepsis/meningitis?
- tachycardia
- bradycardia
- hypotension
What are the hepatic symptoms of neonatal sepsis/meningitis?
- hepatomegaly
- jaundice
What are the GI symptoms of neonatal sepsis/meningitis?
- anorexia
- vomiting
- abdominal distension
- diarrhoea
What are the haematological symptoms of neonatal sepsis/meningitis?
Bleeding disorders
What are the CNS symptoms of neonatal sepsis/meningitis?
- lethargy
- irritability
- seizure
What are the common causative organisms of neonatal sepsis/meningitis?
- group B streptococcus
- escherichia coli
- (listeria monocytogenes - very rare)
How is neonatal sepsis/meningitis diagnosed?
Blood, urine, and CSF culture (lumbar puncture) - to determine origin of sepsis
