Infections in Pregnancy and the Neonate

Question 1

Define Congenital

Answer 1

Condition present at birth (inherited or caused by environment)

Question 2

Perinatal Period

Answer 2

Commences at 22 weeks (154 days) of gestation and ends 7 days after birth.

Question 3

Neonatal Period

Answer 3

first 28 days of life

Question 4

Postnatal

Answer 4

first 6 week after birth

Question 5

Vertical Transmission

Answer 5

• Across the placenta (intrauterine)
• During birth
• Direct contact with maternal body fluids
• Proloned rupture of membranes
• After birth (from mother or other contacts)

Question 6

Congenital Infections

Answer 6

• Rubella, Cytomegalovirus, HIV, Toxoplasma, T. Pallidum, Parvovirus, VZV.
• Manifests as growth retardation, congenital malformation, fetal loss

Question 7

Perinatal Infections

Answer 7

• Gonococcus, chlamydia, HSV, VZV, group B strep, E.Coli, Listeria
• Manifests as meningitis, septicaemia, pneumonia, preterm labour

Question 8

Postnatal Infections

Answer 8

• N. gonorrhoeae, Chlamydia
• from breast milk - HIV, CMV
• Umbilicus - staphylococcal, tetanus
• Person-to-person - group B strep, listeria, E.Coli
• Manifests as meningitis, septicaemia, conjunctivitis, pneumonitis

Question 9

Rubella

Answer 9

• Primary maternal rubella infection in 1st trimester. High risk of congenital rubella syndrome. Initial signs include hepatitis-associated jaundice, haemolysis, thrombocytopenia. Microcephalus, cataract, deafness, heart defects in foetus. Low birth weight; failure to attain developmental milestones. Termination of pregnancy in some cases. IgM persists for 1st three months of life.
• Vaccine - MMR vaccine (introduced in 1988)
• Pre-natal Screening - Screening does not give any protection, may provide false reassurance to mothers.

Question 10

Varicella Zoster Virus (VZV)

Answer 10

• Causes chicken pox/shingles. Primary maternal VZV infection in 1st 20 weeks of gestation, may cause congenital varicella syndrome. Eye defects, hypoplastic limb or microcephalus. VZV infection around delivery - may cause neonatal varicella syndrome and rash, pneumonitis.
• Prevention and Treatment - IV Aciclovir (high dose). VZV immunoglobulin - to mother or neonate, within 7-10th day of exposure, may prevent foetal/neonatal varicella syndrome. Live vaccine (Varivax or Varilrix) - not routine.

Question 11

Parvovirus

Answer 11

Parovirus B19 - maternal infection during 1st 20 weeks of gestation. Foetal anaemia, hydrops in <10%. Diagnosis: amniocentesis, chorionic villus sampling (cordocentesis - decreasing use). Monitor for foetal ascites. Slapped cheek syndrome (“fifth disease”).

Question 12

Cytomegalovirus (CMV)

Answer 12

• Herpes family of viruses. Maternal infection = either primary or reactivation. May cause deafness, retardation in foetus. Diagnosis: NAAT on: amniotic fluid and neonatal blood/urine within 3 weeks of birth.

Question 13

Listeria Monocytogenes

Answer 13

Listeriosis - often unapparent in maternal infection. Transplacental transmission. Infection in early pregnancy leads to foetal death. Infection in later pregnancy leads to associated with premature birth. Complications of foetal infection include bacteraemia, hepatosplenomegaly, meningoencephaly, thrombocytopaenia, pneumonitis. Intrapartum exposure leads to memingitis and bacteraemia. Culture: blood, CSF, placental tissue, lochia. Isolation of infected mother and baby. Treatment and Management: take specialist ID advice re: antibiotics. Prevention is key.

Question 14

Toxoplasma Gondii

Answer 14

Toxoplasmosis - incidence varies globally (common in France; rare in UK), Cats are definitive hosts. Faecal contamination. Infected, under-cooked meat; infected fruit and vegetables. Infected pregnancy has a 1 in 3 chance of transplacental transmission. Infection in 1st and 2nd trimester: stillborn, death soon after birth, cerebral calcification, cerebral palsy, epilepsy, chorioretinitis. Maternal infection confirmed by presence of IgM antibodies. Treatment with Spiramycin.

Question 15

Human Immunodeficiency Virus (HIV)

Answer 15

In absence of treatment: risk of vertical transmission (25-30%). Greatest risk with advanced maternal disease/high viral load. Implementation of: HIV testing, counselling, antiretroviral medication, delivery by caesarean section prior to onset of labour, discouraging breastfeeding. Reduction in mother-to-child transmission of HIV = hugely effective public health initiative.

Question 16

Treponema Pallidum

Answer 16

Syphilis. Rare in neonates due to pre-natal screening. Fever, rash, condylomata, mucosal fissures. Treatment using benzylpenicillin.

Question 17

Herpes Simplex Virus (HSV)

Answer 17

Cold sores, herpetic whitlow.

Question 18

Staphylococcus Aureus

Answer 18

Scalded skin syndrome caused by staphylococcus aureus toxin.

Question 19

Zika Virus

Answer 19

Spread through bite of infected Aedes species mosquito. Fever, rash, joint pain, conjunctivitis. May be transmitted from male to sexual partner(s). Infection during pregnancy could cause severe congenital brain effects e.g. microcephaly, Guillain-Barre syndrome. No vaccine or treatment yet. Prevention - barrier contraception, avoid mosquito bites.

Question 20

Ophthalmia Neonatorum

Answer 20

Conjunctivitis contracted by newborns during delivery. Mother infected N. gonorrhoeae or C. trachomatis. Can cause blindness without treatment.

Question 21

Maternal Microbiota

Answer 21

Newborn’s gut microbiota can affect its own immune system. There is some evidence to suggest mother’s microbiome shapes the immune system of her offspring.

Question 22

UTIs in Pregnancy

Answer 22

Pyelonephritis is the most common serious medical condition seen in pregnancy. During pregnancy, urinary tract changes predispose women to infection. Ureteral dilation is seen due to compression of the ureters from the gravid uterus. Hormonal effects of progesterone also may cause smooth muscle relaxation leading to dilation and urinary stasis, and vesicoureteral reflux increases. The most significant factor predisposing women to UTI in pregnancy is asymptomatic bacteriuria (ASB). ASB is defined as more than 100,000 organisms/ml on a clean catch urinalysis obtained from an asymptomatic patient. If asymptomatic bacteriuria is untreated in pregnancy, the rate of subsequent UTI is approximately 25%. Due to both the high rate and potential seriousness of pyelonephritis, it is recommended that all pregnant women be screened for ASB at the first prenatal visit. This is most often done with a clean catch urine culture. Treatment of ASB decreases the rate of clinical infection to 3-4%.