Teratogens I Flashcards
What pathogens are capable of vertical transmission?
viruses (echo virus, Hep A and B, measles, mumphs, rubella)
parasites
bacteria (group B strep, chlamydia)
What are the potential effects of maternal infection on pregnancy outcomes?
pregnancy loss teratogenicity preterm birth other pregnancy complications transient in-utero infection infection of the fetus/newborn unknown
What factors affect transmission risk and fetus/newborn disease severity in MTC of viral pathogens?
gestational age at time of infection
circulating maternal viral load
newly acquired infections
maternal immunologic responses
What factors influence transmission risk between mother and fetus for HIV?
maternal viral load breast feeding ruptured membranes prematurity concomitant infections (Hep C) acquiring HIV at the same time as pregnancy (postulated)
What are adverse pregnancy outcomes associated with treatment of HIV infection with DTG?
pregnancy loss, prematurity, preeclampsia, gestational DM
What are adverse maternal effects associated with treatment of HIV infection with DTG?
metabolic complications (lipodystrophy, insulin resistance, osteopenia, abnormal lipid metabolism) toxicities (hepatitis, pancreatitis, peripheral neuropathy, kidney stones)
What are adverse fetal outcomes associated with treatment of HIV with DTG?
congenital malformations
neural tube defects
longterm health risks including HIV infection
How can Hep B be transmitted?
vertically (from mother to child)
sexually
other close (non-sexual) contact
*highly contagious
Approximately _____% of healthy adults will clear Hep B infections and develop antibodies, however in newborns exposed to Hep B, the majority ______.
90-95
will develop chronic infections
How is Hep B managed in pregnancy?
prenatal screening (HBsAg+ screening routine part of prenatal care) at risk infants receive passive and active immunization at birth to prevent MTCT
What is the difference between passive and active immunization of infants for Hep B?
passive- Hep B IG within 12 hours of birth (100% effective in HBeAg- women but only 85% effective in HBeAg+ women)
active- Hep B vaccine within 12 hours of birth
What is the rate of vertical transmission of Hep C?
10-15%
______% of children born to Hep C infected women will they themselves have chronic liver disease.
5-6
What are the MTCT rates of Herpes Simplex Virus?
primary infection near term- 30-50%
recurrent infection near term- <1% transmission
How can you prevent neonatal herpes?
preventing maternal acquisition of HSV during pregnancy
avoiding exposure to asymptomatic HSV shedding and clinically apparent herpetic lesions during delivery
What antepartum management is available for mothers with HSV?
serologic testing used for counseling women of partners with known genital herpes (seronegative women should avoid intercourse with partners in third trimester)
first episode genital herpes or frequent, severe recurrences treat with antiviral suppression (usually valacyclovir)
in women with frequent recurrences, supression reduces frequency of genital recurrences and reduces the risk of delivery via c-section
What intrapartum management is used for women with HSV?
C-section recommended for those with active disease (either primary or recurrent)
note this does not completely prevent vertical transmission
consider IV acyclovir as well
What neonatal HSV management is available?
careful follow-up of exposed infants (routine surveillance cultures from mucosal surfaces or routine IV acyclovir if maternal infection was primary HSV) neonatal disease (may be limited to skin and mucous membranes, systemic including CNS involvement) treated with IV acyclovir from 14-21 days depending on severity
Primary CMV in the US complicates _____% of all pregnancies.
1-3
What is the vertical risk of transmission for CMV?
30-40%
What is the rate of non-primary (reactivation, re-infection) CMV during pregnancy?
as high as 13.5%
What is the risk of vertical transmission for non-primary CMV?
0.15-2%
CMV is the most common congenital infection occurring in _____% of neonates and is the leading cause of ______.
0.2-2.2%
congenital hearing loss
What are the symptoms of primary CMV at birth in infants?
small for gestational age, petechiae, thrombocytopenia, jaundice, hepatosplenomegaly, microcephaly, seizures, and chorioretinitis often fatal (survivors commonly have visual impairments, hearing loss, and mental retardation)
_____% of infants born with primary CMV infections will be symptomatic at birth.
10-15
5-10% of infants with asymptomatic primary CMV at birth will have _______.
varying degrees of hearing loss and/or coordination problems
Describe strategies to prevent MTCT of CMV.
handwashing and effective vaccination programs
What kinds of maternal screenings are available for CMV?
CMV IgM (not reliable- high false positive) CMV Avidity testing
How should pregnancies complicated by maternal primary CMV be evaluated?
US (best tool) and amnio
CMV detected in amniotic fluid by either culture or PCR (detection of CMV in amniotic fluid does not predict severity of newborn disease)
What treatments strategies are possible for MTCT prevention of CMV?
immune based treatment to interrupt transmission is in currently being studied
What is Congenital Rubella Syndrome?
infection of a fetus with rubella causing deafness, cataracts, heart defects, microcephaly, mental retardation, bone alterations, liver and spleen damage, and/pr fetal death or premature delivery
What effects the severity of damage to a fetus with Congenital Rubella Syndrome?
gestational age at infection
defects rare after 20 weeks gestation
85% of infants affected if maternal infection occurs during first trimester
What is the risk of vertical transmission of toxoplasmosis?
50% if acute toxoplasmosis occurs during pregnancy
maternal infections early in pregnancy are less likely to be vertically transmitted than infections later in gestation
How can congenital toxoplasmosis be identified on US?
chorioretinitis, intracranial calcifications, hydrocephalus
What are the long term effects of congenital toxoplasmosis infection of infants in-utero?
mostly asymptomatic at birth with development of learning and visual impairments later in life
What is the risk of congenital varicella?
2% if infection occurs between 13-20 weeks of gestation
17-30% risk of severe infection if acute varicella in pregnant woman from 5 days before to 2 days after delivery
What are the symptoms of congenital varicella syndrome?
chorioretinitis, congenital cataracts, cerebral cortical atrophy, variable degrees of limb atrophy, skin scarring, and GER
What is the risk of MTCT of Zika virus?
1-10%
What are the symptoms of congenital Zika syndrome in infants born to mothers with known Zika/
microcephaly, ventriculomegaly, intracerebral calcifications, ocular problems, damage to central and peripheral motor neurons
How can mothers decrease risk of Zika?
don’t travel where zika is
use mosquito protection (even during pregnancy)
if returning from travels in affected areas, use condoms and wait to conceive
What vaccinations are contraindicated in pregnancy?
MMR
Varicella
live attenuated influenza vaccine
What is cocooning?
vaccination of mothers post-partum and other close contacts to protect infants
