Perinatal infections
Infections causing congenital
abnormalities
• Rubella
• Infective organism
• Rubella virus is a togavirus spread by droplet transmission.
• Screening
• All women should be offered rubella susceptibility screening early in
their pregnancy to identify women at risk of contacting rubella
infection and to enable vaccination in the post-natal period for the
protection of future pregnancies.For pregnant women who are
screened and rubella antibody is not detected, rubella vaccination
after pregnancy should be advised. Vaccination during pregnancy is
contraindicated because of a theoretical risk that the vaccine itself
could be teratogenic, as it is a live vaccine, women who are
vaccinated postpartum should be advised to use contraception for
one month.
Infections causing congenital
abnormalities
• Clinical features
• Rubella infection is characterized by a febrile rash but
may be asymptomatic in the mother in 20–50 per
cent of cases. Features of congenital rubella
syndrome can include
sensorineural deafness,
congenital cataracts, blindness, encephalitis and
endocrine problems
. The risk of congenital rubella
infection reduces with gestation. Congenital infection
in the first 12 weeks of pregnancy among mothers
with symptoms is over 80 per cent and reduces to 25
per cent at the end of the second trimester.
Infections causing congenital
abnormalities
• One hundred per cent of infants infected during the
first 11 weeks of pregnancy have rubella defects,
whereas primary rubella contracted between 16
and 20 weeks of gestation carries only a minimal
risk of deafness. Rubella infection prior to the
estimated date of conception or after 20 weeks
gestation carries no documented risk to the fetus.
Infections causing congenital
abnormalities
• Syphilis
• Syphilis is a sexually acquired infection caused byTreponema pallidum.
• Clinical features
• Primary syphilis may present as a painless genital ulcer 3–6 weeks after the
infection is acquired (condylomata lata) ,however, this may be on the cervix
and go unnoticed. Secondary manifestations occur 6 weeks to six months
after infection and present as a maculopapular rash or lesions affecting the
mucous membranes. Ultimately, 20 per cent of untreated patients will
develop symptomatic cardiovascular tertiary syphilis and 5–10 per cent will
develop symptomatic neurosyphilis. In pregnant women with early
untreated (primary or secondary) syphilis, 70–100 per cent of infants will
be infected and approximately 25 per cent will be stillborn. Mother-to-child
transmission of syphilis in pregnancy is associated with fetal growth
restriction (FGR), fetal hydrops, congenital syphilis (which may cause long-
term disability), stillbirth, preterm birth and neonatal death.
•
• Screening
• Because treatment is so effective, routine antenatal screening for
all pregnant women is recommended. . These can be detected by
serological tests.
• Non-treponemal tests detect non-specific treponemal antibodies
and include the Venereal Diseases Research Laboratory (VDRL) and
rapid plasma reagin (RPR) tests. Treponemal tests detect specific
treponemal antibodies and include enzyme immunoassays (EIA), T.
pallidum haemagglutination assay (TPHA) and the fluorescent
treponemal antibody-absorbed test (FTA-abs) Non-treponemal
tests, on the other hand, may result in false negatives, particularly
in very early or late syphilis, in patients with reinfection or those
who are HIV positive. The VDRL may be falsely positive in women
with lupus. Therefore, positive results should be interpreted with
caution and the pregnant woman should be referred for expert
assessment and diagnosis in a genitourinary medicine clinic.
Infections causing congenital
abnormalities
• Management
• The initial step is to confirm the diagnosis and to test for any other
sexually transmitted diseases. Once a diagnosis of syphilis is
confirmed the genitourinary medicine clinic will institute
appropriate contact tracing of sexual partners. Older children may
also need to be screened for congenital infection. Parenteral
penicillin has a 98 per cent success rate for preventing congenital
syphilis If a woman is not treated during pregnancy her baby should
be treated after delivery. An infected baby may be born without
signs or symptoms of disease but if not treated immediately, may
develop serious problems within a few weeks. Untreated babies
often develop developmental delay, have seizures or die
•
Infections causing congenital
abnormalities
• Toxoplasmos
• Toxoplasma gondii is a protozoan parasite found in cat faeces, soil or
uncooked meat
• The initial infection may be relatively asymptomatic, or may be a
glandular fever-like illness. Parasitaemia usually occurs within 3
weeks of infection. Therefore, congenital infection is only a significant
risk if the mother acquires the infection during or immediately before
pregnancy. Infection during the first trimester of pregnancy is most
likely to cause severe fetal damage (85 per cent), but only 10 per cent
of infections are transmitted to the fetus at this gestation. In the third
trimester 85 percent of infections are transmitted, but the risk of
fetal damage decreases to around 10 per cent. Severely infected
infants may have ventriculomegaly or microcephaly, chorioretinitis
and cerebral calcification.
Infections causing congenital
abnormalities
• Management
• The diagnosis of primary infection with toxoplasmosis during
pregnancy is made by the Enzyme-linked immunosorbant
assays for IgM antibody. However,
IgM may persist for
months or even years, so often serial testing for rising titres
is necessary.
If suspicion of congenital toxoplasmosis has
arisen because of an abnormal ultrasound scan of the fetus,
an amniocentesis can be performed. Polymerase chain
reaction (PCR) analysis of amniotic fluid is highly accurate for
the identification of T. gondii. .Spiramycin treatment can be
used in pregnancy (a 3-week course of 2–3 g per day).
•
Infections causing congenital
abnormalities
• Chickenpox
• Infective organism
• Chickenpox is caused by the varicella zoster virus (VZV),
a herpes virus which is transmitted by droplet spread.
• Clinical features
• Non-immune pregnant women are more vulnerable to
chickenpox and may develop a serious pneumonia,
hepatitis or encephalitis. . It may also cause the fetal
varicella syndrome (FVS) or varicella infection of the
newborn.
Infections causing congenital
abnormalities
• Management
• Women should be asked whether they have had chickenpox at
the initial booking visit. If they have not had chickenpox, they
should be advised to avoid contact with it during pregnancy,
and if they accidentally come into contact with it should advise
their doctor or midwife about the exposure as soon as
possible. When contact occurs with chickenpox, a careful
history must be taken to confirm the
significance of the
contact
(length of exposure and closeness of contact) and the
susceptibility of the patient
. Significant contact is defined as
being in the same room as someone for 15 minutes or more,
or face-to-face contact.
Infections causing congenital
abnormalities
• Testing for immunity
• If a women reports that she has been in contact with
chickenpox, she should have a blood test for confi
rmation of VZV immunity, by testing for VZV IgG. This
can usually be performed within 24–48 hours and the
virology laboratory may be able to use
serum
stored from booking antenatal bloods
•
• Management of the non-immune woman exposed
• to chickenpox
• If the pregnant woman is not immune to VZV and she has had a
significant exposure, she should be given varicella zoster
immunoglobulin (VZIG) as soon as possible
• Management of chickenpox in pregnancy
• Women with chickenpox should avoid contact with susceptible
individuals; that is, other pregnant women and neonates, until
the lesions have crusted over. This is usually about 5 days after
the onset of the rash. Symptomatic treatment and hygiene is
advised to prevent secondary bacterial infection of the lesions.
oral aciclovir 800 mg five times per day for 7 days be prescribed
for pregnant women with chickenpox if they present within 24
hours of the onset of the rash and if they are more than 20
weeks gestation. Aciclovir should be used cautiously before 20
weeks gestation
• The fetus
• Spontaneous miscarriage does not appear to be increased if
chickenpox occurs in the first trimester. FVS is characterized
by one or more of the following:
• • skin scarring in a dermatomal distribution;
• • eye defects (microphthalmia, chorioretinitis, cataracts);
• • hypoplasia of the limbs;
• • neurological abnormalities
• This only occurs in a minority of infected fetuses
(approximately 1 per cent). FVS has been reported to
complicate maternal chickenpox that occurs as
• early as 3 weeks and up to 28 weeks of gestation.
• Maternal infection around the time of delivery
• If maternal infection occurs at term, there is a
significant risk of varicella of the newborn. Elective
delivery should normally be avoided until 5–7 days
after the onset of maternal rash to allow for the passive
transfer of antibodies from mother to child. Neonatal
ophthalmic examination should be organized after
birth. If birth occurs within the 7-day period following
the onset of the maternal rash, or if the mother
develops the chickenpox rash within the 7-day period
after birth, the neonate should be given VZIG
•
Infections acquired around the time
of
delivery with serious neonatal
consequences
Infections acquired around the time of
delivery with serious neonatal
consequences
• Herpes
• Genital herpes presents as ulcerative lesions on the
vulva, vagina or cervix. The woman may give a history
of this being a recurrent problem, in which case the
lesion is often less florid. A primary infection may be
associated with systemic symptoms and may cause
urinary retention. Neonatal herpes may be caused by
HSV-1 or HSV-2, as either viral type can cause genital
herpes.
• Almost all cases of neonatal herpes occur as a result of
direct contact with infected maternal secretions, Factors
influencing transmission include
the type of maternal
infection (primary or recurrent), the presence of
transplacental maternal neutralizing antibodies, the
duration of rupture of membranes before delivery, the use
of fetal scalp electrodes and the mode of delivery
. The
risks are greatest when a woman acquires a new infection
(primary genital herpes) in the third trimester, particularly
within 6 weeks of delivery, as viral shedding may persist
and the baby is likely to be born before the development
of protective maternal antibodies.
Infections acquired around the time of
delivery with serious neonatal
consequences
• Management
• Any woman with suspected first episode genital
herpes should be referred to a genitourinary
physician, who will confirm the diagnosis by viral
culture or PCR, advise on management and arrange
a screen for other sexually transmitted infections.
The use of aciclovir is associated with a reduction in
the duration and severity of symptoms and a
decrease in the duration of viral shedding.
• Primary infections
• Caesarean section should be recommended to all women presenting with
primary episode genital herpes lesions at the time of delivery, or within 6
weeks of the expected date of delivery. For women who develop primary
genital herpes lesions within 6 weeks of delivery and who opt for a vaginal
birth, rupture of membranes should be avoided and invasive procedures
such as fetal scalp electrodes, or fetal scalp pH measurement should not be
used. Intravenous aciclovir given intrapartum to the mother and
subsequently to the neonate may be considered. The neonatologist should
be informed and may advise acyclovir treatment of the baby.
• Recurrent episodes
• A recurrent episode of genital herpes occurring during the antenatal period
is not an indication for delivery by Caesarean section.
•
•
•
Infections acquired around the time of
delivery with serious neonatal
consequences
• Group B streptococcus
• Infective organism
• Group B streptococcus (GBS) (Streptococcus agalactiae) is a
Gram-positive coccus frequently found as a vaginal commensal.
It can cause sepsis in the neonate and transmission can occur
from the time the membranes are ruptured until delivery.
• Clinical features
• The mother will not have symptoms as GBS is a common vaginal
commensal.
• An infected neonate may demonstrate signs of neonatal sepsis
including sudden collapse, tachypnoea ,nasal flaring, poor tone,
jaundice, etc.
• Intrapartum antibiotic prophylaxis
• It is during labour that infection of the fetus/neonate
occurs. Antibiotics given in labour are estimated to be 60–
80 per cent effective in reducing early-onset neonatal GBS
infection.
• Risk factor-based prophylaxis
• • intrapartum fever
• • prolonged rupture of membranes (PROM) greater than
18 hours
• • prematurity less than 37 weeks
• • previous infant with GBS.
• • Incidental detection of GBS in current pregnancy
• • GBS bacteruria.
• It is recommended that intravenous penicillin 3 g
be given as soon as possible after the onset of
labour and 1.5 g 4-hourly until delivery.
Clindamycin 900 mg should be given
intravenously 8-hourly to those allergic to
penicillin. Women undergoing planned
Caesarean delivery in the absence of labour or
membrane rupture do not require antibiotic
prophylaxis for GBS.
• Perinatal infections causing
long-term disease
Perinatal infections causing
long-term disease
• HIV
• Infective organism
• The HIV virus is an RNA retrovirus transmitted through
sexual contact, blood and blood products, shared
needles for i.v. drug users, vertical (motherto-
• child) transmission which mainly occurs in the late third
trimester, during labour or delivery or breastfeeding.
• Screening
Perinatal infections causing
long-term disease
• Clinical features
• Infection with HIV begins with an asymptomatic
stage with gradual compromise of immune function
eventually leading to acquired immunodefi ciency
syndrome (AIDS). The time between HIV infection
and development of AIDS ranges from a few
months to as long as 17 years in untreated patients.
Perinatal infections causing
long-term disease
• Management
• The principal risks of mother-to-child (vertical)
transmission are related to maternal plasma viral load,
obstetric factors and infant feeding
• Interventions to reduce the risk of HIV transmission can
reduce the risk of vertical transmission from 25 to 30 per
cent to less than 2 per cent:
• • anti-retroviral therapy, given antenatally and
intrapartum to the mother and to the neonate for the first
4–6 weeks of life
• • delivery by elective Caesarean section
• • avoidance of breastfeeding.
Perinatal infections causing
long-term disease
• An elective vaginal delivery is an option for
women taking
triple drug antiretroviral therapy
who have a viral load below 50
copies/mL at the
time of delivery. Women who opt for a planned
vaginal delivery should have their membranes
left intact for as long as possible. Use of fetal
scalp electrodes and fetal blood sampling should
be avoided. A Caesarean delivery is
recommended if viral load is above 50 copies/
mL at the time of delivery.
Perinatal infections causing
long-term disease
• Management of infants
• The cord should be clamped as early as possible after
delivery and the baby should be bathed immediately
after the birth. all women who are HIV positive should
be advised not to breastfeed their babies as this
increases the risk of mother-to-child transmission. All
infants born to women who are HIV positive should be
treated with antiretroviral therapy from birth. direct
viral amplify- cation by PCR is used for the diagnosis of
infant infections. Typically, tests are carried out at
birth, then at 3 weeks, 6 weeks and six months.
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