Infection in pregnancy

Rubella (German Measles)

• Viral infection person-to-person contact
• MMR vaccine makes it rare now
• 80% fetal infection first trimester, and 25% at end of third trimester
• Maternal rubella infection causes sensorineural deafness, cataracts, congenital heart disease, learning difficulties, hepatosplenomegaly and microcephaly

Salmonella spp.

• Gram-negative bacterium in raw or partially cooked eggs, raw meat and chicken
• Pregnancy increases incidence and severity
• Gastroenteritis
• Fetus is okay

Listeria

• Gram-positive coccus Listeria monocytogenes
• Found in soil, animal faeces, pate and unpasteurized dairy products such as soft cheese
• Incidence and severity of infection increased in pregnancy
• Fever, headache, malaise, backache, abdominal pain, pharyngitis, and conjunctivitis
• Blood cultures or placental neonatal swabs diagnostic
• High-dose penicillin treats
• During pregnancy can lead to miscarriage, stillbirth, preterm delivery and neonatal listeriosis, which carries a 50% mortality rate

Group B streptococci

• 1/4 of women have group B streptococcal vaginal colonization at some stage of their pregnancy
• Asymptomatic to mother and generally only picked up on vaginal swabs taken for other reasons
• 1/65 neonatal deaths by causing overwhelming neotatal infection
• Antibiotics given in labour to reduce neonatal infection risk
• No screening programme in place at the moment

Chickenpox

• Caused by varicella-zoster virus (human herpesvirus 3), is spread via the airborne route
• It affects 3/1000 pregnancies
• 90% women immune due to previous infections
• Prodromal malaise and fever, followed by itchy vesicular rash
• Sequelae of maternal infection are more serious in pregnant women, with 10% risk of pneumonia and 1% mortality rate
• Diagnosis is clinical and treatment is supportive, with advice to avoid other pregnant women
• Fetal varicella syndrome if before 16 weeks: dermatomal skin scarring, neurological defects, limb hypoplasia and eye defects

Toxoplasmosis

• Toxoplasma gondii is a parasite that comes from unwashed fruit and vegetables, raw/cured/poorly cooked meat, unpasteurized goats' milk, or contamination from soil or cat faeces
• The incidence is 2 in 1000 pregnancies
• 30% of women are immune due to previous infection
• It is rare for mothers to display clinical features, although some develop flu-like symptoms
• Treatment is with spiramycin
• Fetal infection occurs in 40% of cases, with the majority occurring at higher gestations (severity is greatest at lower gestations)
• Fetal effects of toxoplasmal infection are miscarriage, stillbirth, hydrocephalus, deafness and blindness. Fetal infection can be diagnosed by amniocentesis or cordocentesis

Cytomegalovirus

• Cytomegalovirus affects 3 in 1000 live births
• Urine, saliva, and other bodily products
• Maternal infection is usually asymptomatic, after a 3 to 12 week incubation period
• Maternal primary infection can be confirmed by immunoglobulin M (IgM) in the blood, and maternal immunity is revealed by detecting IgG
• There is no treatment and therefore no benefit to screening
• Fetal infection diagnosed by amniocentesis or cordocentesis
• 10-15% infected fetuses developed symptoms
• 80% develop symptoms later in life - learning difficulties, visual impairment, progressive hearing loss or psychomotor retardation, 10-20% showing signs of infection at birth (hydrops, intrauterine growth restriction, microcephaly, hydrocephalus, hepatosplenomegaly and thrombocytopenia)

Parvovirus B19

• Spread by respiratory droplets
• Outbreaks in schools and manifests in children as erythema infectiosum - a 'slapped-cheek' appearance
• Also known as 5th's disease
• Fetal death in 9%
• Second trimester holds highest risk of fetal infection
• Fetal sequelae are non-immune hydrops due to chronic haemolytic anaemia and myocarditis
• In utero blood transfusion of hydropic fetuses may prevent demise
• No long term sequelae if they survive