Preventing Fetal Exposure to Teratogen

• Teratogens - is any factors, chemical or physical that adversely affects the fertilized ovum, embryo or fetus.
• Fetus - is extremely vulnerable to environmental injury
• The causes of many anomalies in utero are still Unknown
• Radiation - in small amount causes no damage unless in large doses causing fetal defects and death
• Timing - if teratogen introduced before implantation or 2-8 wks. of embryonic life
• Last trimester less harmed since all organs are formed
• Syphilis and Toxoplasmosis at late stage of gestation can cause abnormalities in normally formed organs.
• Syphilis - is a sexually transmitted infection caused by the bacterium “ Treponema pallidum”
• Toxoplasmosis - a disease caused by protozoan parasite, transmitted from mother to fetus.
• Lead and Mercury affects the nervous tissue
• Thalidomide - cause limb defects
• Tetracycline - causes tooth enamel deficiency and long bone deformities.
• Rubella - virus which can affect eyes, ears, heart and brain
• Teratogenic Maternal Infections – involve either sexually transmitted or systemic infections. (Viral, bacterial, or Protozoa)
• TORCH screen – is an immunologic survey to determine whether common infections exist in either the pregnant woman or the newborn
• TORCH

  • T - Toxoplasmosis
  • O - Others: Syphilis
  • R - Rubella
  • C - Cytomegalovirus
  • H - Herpes
• Toxoplasmosis transmission

  • Uncooked meat
  • Handling Cat stool or Cat litter
• Toxoplasmosis

  • Effects on Mother – almost no symptoms except for a few days of malaise and posterior cervical lymphadenopathy
  • Effects on Fetus - CNS damage
  • Intracerebral calcification
  • Retinal deformities causes eye inflammation, eye pain, blurred vision, and possibly permanent damage, including blindness
• Pyrimethamine - an anti protozoal agent administered with caution early in pregnancy to prevent reducing folic acid levels
• Rubella virus (German Measles) – causes rashes and mild systemic illness in a woman
• Effects on Fetus: (Rubella)

  • Hearing impairment
  • Cognitive and motor challenges
  • Cataracts, Cardiac defects
  • Pulmonary stenosis
  • Restricted intrauterine growth
• Effects on Fetus (Rubella)

  • Small for gestational age
  • Thrombocytopenic purpura
  • Facial clefts
• greater than 1:8 – suggest immunity to the disease
• less than 1:8 – susceptible to viral invasion
• Prevention: (Rubella)

  • Vaccine
  • Rubella titer
  • All pregnant woman should avoid contact with children with rashes
  • Infants who are born to mother infected with rubella is isolated from other newborn
  • Nurses who care for mother and newborn should receive immunization
• CYTOMEGALOVIRUS – A MEMBER OF HERPES VIRUS THAT CAUSES EXTENSIVE DAMAGE TO A FETUS WHILE CAUSING FEW SYMPTOMS IN A WOMAN
• Effects on Fetus: (Cytomegalovirus)

  • Hydrocephalus
  • Microcephaly
  • Eye damage, deafness and chronic liver disease
  • Skin - large petechiae (blueberry muffins lesion)
• Prevention: (Cytomegalovirus)

  • Routine screening for CMV during pregnancy
  • Advise to wash hands before eating and avoid crowds of young children at daycare or nursing settings
• HSV 2 – the virus spreads into the bloodstream and crosses the placenta to a fetus
• Effects on Fetus: (HSV 2)

  • 1st trimester - severe congenital anomalies and spontaneous miscarriage
  • 2nd to 3rd trimester - Premature birth, Intrauterine growth restriction
• Prevention: (HSV 2)

  • Intravenous Acyclovir (Zovirax) or valacyclovir (Valtrex)
  • Practice safe sex
  • Advising adolescents to obtain a vaccine against HPV
• Syphilis – Is a sexually transmitted infection cause by a spirochete “Treponema pallidum"
• Effects on Fetus: (Syphilis) l Untreated beyond 18th wks. of gestation

  • a. Hearing impairment
  • b. Cognitive challenge
  • c. Osteochondritis
  • d. Fetal death
• Benzathine penicillin G - drug of choice for syphilis (IM)
• Prevention: (Syphilis)

  • Practice safe sex
  • Serologic Screening - VDRL & RPR
• Lyme Disease - a multisystem disease caused by the spirochete Borrelia burgdorferi
• Lyme Disease

  • Infection in pregnancy - can result in spontaneous miscarriage or severe congenital anomalies
• Treatment for Lyme Disease

  • Pregnant - Penicillin (reduce symptoms)
  • Nonpregnant - Tetracycline and Doxycycline
• POTENTIALLY TERATOGENIC VACCINES

  • Measles
  • HPV
  • Mumps
  • Rubella
  • Poliomyelitis (Sabin Type)
• Teratogenic Drugs

  • Thalidomide - morning sickness and effective anticancer drug
  • Minoxidil (Rogaine) - restore hair growth
  • Valproic acid - seizures
  • Narcotics - intra-uterine growth restriction
  • Cocaine - vasoconstriction