Bacterial Infections in Pregnancy
Bacterial infections can affect pregnant
women from implantation of the fertilized
ovum through the time of delivery and
They may also affect the fetus and newborn.
Many women with these infections are
asymptomatic, necessitating both a high
degree of clinical awareness and adequate
1. Group B Streptococcus
• GBS; Streptococcus agalactiae is the most
common cause of life-threatening infections in
newborns and can also affect the mother.
• Found as part of normal vaginal, rectal, and
• Intrapartum transmission occurs via ascending
spread or at the time of delivery
Urinary tract infections
• Asymptomatic bacteriuria develops in 10-15% of
• Lead to complications such as pyelonephritis and
• All pregnant women should undergo screening
with urine culture at least once during early
• Significant bacteriuria is defined as >100,000
colony-forming units (CFU) of a single organism in
a clean-catch specimen.
• Escherichia coli
• Klebsiella species
• Enterobacter species
• Enterococcus species
• Group B Streptococcus (GBS)
• Staphylococcus saprophyticus
• Proteus mirabilis
• One third of all reported cases of listeriosis occur during pregnancy, typically
during the third trimester
• Mode of transmission-
• ingestion of contaminated food,
• contact with infected animals and
• nosocomial transmission
• Clinical presentation –
• with listeriosis is bacteremia, often asymptomatic; CNS Listeria infections are rare
• Symptomatic pregnant patients - fever, muscle aches, and, occasionally, nausea or
diarrhea during the bacteremic phase of the disease
• Maternal complications-
• spontaneous septic abortion
• premature labor with delivery of an infected baby
• Fetal complications-
• septicemia, meningoencephalitis, or disseminated granulomatous lesions with microabscesses
disseminated granulomatous lesions
• Untreated primary or secondary syphilis in pregnancy leads to a fetal infection rate
of almost 100%
• Maternal Signs & symptoms
– In primary syphilis- a hard, painless red ulcer typically forms on the vulva, cervix, or vagina
– Secondary syphilis -predominantly manifests as a nonpruritic rash that may involve the palms
and soles; fever, lymphadenopathy, and joint pain
– The latent stage causes no symptoms and is still transmissible to the fetus
– Tertiary syphilis can result in cardiovascular or gummatous disease
– Neurosyphilis can occur at any stage, resulting in CNS or ophthalmic presentations
• Complications –
– late abortion
– neonatal death
– latent infection
• Approximately 75% of women with C trachomatis infection are
• The usual mode of transmission to the fetus is vertical during the
second stage of labor
• Maternal complications –
– acute PID, and acute urethral syndrome
– postpartum endometritis
– gestational bleeding in pregnant women
• In neonates- commonly causes conjunctivitis (ophthalmia
neonatorum) and pneumonia
• Gonococcal infections are second only to chlamydial
infections in the number of cases of bacterial STDs
• Gonococcal infections cause no symptoms in
approximately 50% of patients
• Pregnancy is a predisposing factor to the development
of disseminated gonococcal infection
• presents as an arthritis-dermatitis syndrome
• Newborns exposed to gonorrhea during vaginal
delivery can develop an acute conjunctivitis
(ophthalmia neonatorum), sepsis, arthritis, and
viral Infections in Pregnancy
• RUBELLA: ( German Measles).
– Risk of fetal transmission:
• 50-60% of fetuses are affected if maternal primary
infection is in the first month of gestation.
• 22% in the second month,
• 6-10% in the third to fourth month.
Congenital rubella with hemorrhagic
lesions in the skin
– direct: person to person contact ( saliva, milk,
urine, semen, tears, stools, blood, cervical and
– indirect: contaminated fomites.
• in primary CMV infection –
– 30-40% of fetuses will be infected,
– 2-4% of them will develop severe malformations
• If infection occurs in first trimester 4.9% risk of
congenital varicella .
• Congenital Syndrome
– Limb hypoplasia -
– Ocular abnormalities
– CNS abnormalities ( convulsive disorders )
– Dermatomal scarring
Varicella-Zoster Infections Figure 3. Congenital varicella with short-limb
syndrome and scarring of the skin. The mother had varicella during the
first trimester of pregnancy.
Herpes Simplex virus
– Fetal loss
– Congenital Syndrome
– Mucocutaneous lesions
– Disseminated disease
• Transmission occurs at time of delivery in 90-95% of
cases( vaginal delivery).
• Prevention:If lesions present at time of delivery,
recommend caesarean section.
• Most common cause of jaundice during
• HepatitisB transmitted by contaminated blood
,saliva, breast milk, semen .
• Hepatitis B - pregnant women who are
infected transmit the virus transplacentally to
the fetus and at birth.
• Causative agent: by protozoan toxoplasma gondi.
• Risk of fetal infection:
– First Trimester - 15 % ( less incidence of fetal infection but
serious disease is most common ).
– Second Trimester - 25 % .
– Third Trimester - 65 % ( but almost 90% of newborns are
without clinical signs of disease ).
• 40% of fetuses are affected if the mother has the illness.
• the earlier in pregnancy the more damage.
• Maternal symptoms: usually asymptomatic, fever, rash &
eosinophelia If symptomatic ( the CNS prognosis is poor