Perinatal Infections & Teratology Flashcards
____can cause birth defects similar to a genetic syndrome
In utero infections
what time during pregnancy is most at-risk for teratologic events?
first trimester
What does the pattern of in utero infection look like?
The earlier mom gets the infection,
the more problems your baby will have
TORCH
Infectious agents that are teratogenic to the fetus:
Toxoplasmosis
Other (syphilis, varicella, Zika)
Rubella
CMV
Herpes
Toxoplasmosis
- Increase in spontaneous abortions
- Microcephaly
- Chrioretinitis
- Growth restriction
- Hepatosplenomegaly
- Brain calcifications*
which of torch has brain calcifications?
toxoplasmosis & CMV
If you get infected w toxoplasmosis in the first trimester vs the third trimester
First trimester: full spectrum of malformations in the baby
Third trimester: asymptompatic, but higher chance of fetal infeciton
Syphilis (treponema pallidum)
Most newborns are asymptomatic, but others get
- Chorioretinitis, deformed nails, alopecia, maculopapular rash
- Hydrops fetalis*
- Growth restriction
- Hepatosplenomegaly, jaundice, lymphadenopathy, fever
Congenital rueblla syndrome
Main things to remember: peripheral pulmonic stenosis & radiolucencies of long bone
Others: cataracts, rash, deafness, hydrops fetalis, microcephaly, deafness, pneumonia,
Cytomegalovirus (CMV)
Most common infection
90% are asymptomatic, but 10% have hearing loss and some may have metnal retardation
Microcephaly, cataracts
Herpes in 1st or 2nd trimester vs 3rd trimester
Specific structural abnormalities are rare; growth retardation & microcephaly
1st or 2nd: miscarriage, rare cases of disseminated disease
3rd: disseminated disease, skin lesion
Which is mroe dangerous to a baby - primary or secondary herpes?
primary - 50% risk to child thru infected birth canal
secondary - 8% risk
Characteristics of zika virus infection
microcephaly
intracranial abnormalities, e.g. brain calcifications
Considerations in evaluating teratogenic exposure
timing of exposure
duration of exposure
quantity/dose of exposure
teratogenicity of exposure
maternal modulation (metabolism of teratogen)
access to embryo
When is the worst time to be exposed to teratogens?
embryonic period:
2-8 conception eweks
AKA 4-10 menstrual weeks
Fetal alcohol syndrome
CNS: mental retardation, microcephaly, poor coordination, hypotonia, irritability, hyperacitivty
Growth deficiency
Facial characteristics: short palpebral fissures, upturned nose, flat philtrum, smooth, thin upper vermillion, hypoplastic maxilla, retr/micoragnathia, irritable
Category A - D drugs
which has the lowest fetal risk
A is the lowest fetal risk
X = proven risk and contraindicated in pregnancy
Coumarin derivatives (warfarin)
Fetal warfarin syndrome if used in the 1st trimester
Nasal hypoplasia
Stippled epiphysis of bones
thalidomide main symptom
severe phocomelia (limb reduction)
Antieleptic drugs
Dilantin (phenytoin)
Valproic acid
Tegretol (carbamezepine)
Dilantin (phenytoin) –> Fetal hydantoin syndrome
- Craniofacial
- broad nasal bridge
- wide fontanel
- low ahirline
- broad alveolar ridge
- short neck
- microcephaly
- cleft lip/palate
- abnormal ears
- Limb malformations: nail agenesis/hypoplasia!
valproic acid
increase in neural tube defects
Carbamazipine (tegretol)
similar findings as in fetal hydantoin syndrome, but not as common/severe
neural tube defects
