Fetal conditions - Teratology Flashcards
What is the major cause of birth defects?
Unknown; 65%
Chemically induced birth defects, which include those caused by medications, are believed to account for ____ percent of all birth defects
Less than 1
Teratogen vs hadegen vs trophogen
- An agent that interferes with normal maturation and function of an organ
- Any agent that acts during embryonic or fetal development to produce a permanent alteration of form or function
- An agent that alters growth
- An agent that interferes with normal maturation and function of an organ
- Hadegen
- Any agent that acts during embryonic or fetal development to produce a permanent alteration of form or function
- __Teratogen
- An agent that alters growth
- Trophogen
Summary:
- Hadegen – maturation and function
- Trophogen – growth
Memory aid:
- Growthrophogen
- AlTERation – TERatogen
Criteria for a teratogen
- The defect must be completely characterized
- The agent must cross the placenta
- Exposure must occur during a critical developmental period
- There must be a biologically plausible association
- Epidemiological findings must be consistent
- The suspected teratogen causes a defect in an animal
Teratogenesis is studied by ____
Treating pregnant female animals of at least 2 species at selected times during early pregnancy when organogenesis takes place
Ethanol is a potent teratogen and can cause fetal alcohol syndrome characterized by ____, ____ and ____
- Central nervous system dysfunction
- Growth restriction (pre- or post-natal)
- Facial abnormalities
- Small palpebral fissures
- Thin vermilion border
- Smooth, hypoplastic philtrum
Memory aid:
-
Alcoholic C-G-F
- CNS dysfunction
- Growth restriction
- Facial abnormalities
Binge drinking has been linked to an increased risk of ____
Stillbirth
Fetal alcohol syndrome
- Most severe form
- Mechanism
- Most severe form
- Heart-lung fistulas and holoprosencephaly
- Mechanism
- Failure of cell migration
Both ____ and ____ have been reported in preterm newborns and adults treated with gentamicin or streptomycin
Nephrotoxicity and ototoxicity
What may develop when chloramphenicol is given to preterm neonate?
Gray baby syndrome
- Cyanosis
- Vascular collapse
- Death
Teratogenic effects of nitrofurantoin
Seen in first trimester
- Cleft
- Hypoplastic left heart syndrome
- ASD
- Micropthalmia
Memory aid:
-
Nitro causes micro
- Small left heart
- Small eyes
- Septal defect
- Cleft
Effects of sulfonamides
- Kernicterus
- Anencephaly
- Left ventricular outflow tract obstruction
- Choanal atresia
- Diaphragmatic hernia
Tetracycline may cause:
- When used after 25 weeks
- Yellow-brown discoloration of deciduous teeth
- Deposition in fetal long bone
Effects of immunosuppressants
- Corticosteroid
- Mycophenolic acid
- Corticosteroid
- Cleft
- Mycophenolic acid
- Miscarriage or malformation (ear defects)
Memory aid:
- _C_orticosteroid | _C_left
- _M_ycophenolat_E_ – _M_iscarriage or _M_alformation _E_ar defect
Effects of diethylstilbestrol (DES)
- Female
- Vaginal clear cell adenocarcinoma
- T-shaped uterine cavity
- Cervical collar
- Breast cancer
- Male
- Epididymal cysts
- Hypospadias
- Cryptorchidism
Effect of warfarin
- 6th to 9th week
- 2nd and 3rd trimester
- Generally
- 6th to 9th week
- Warfarin embryopathy (chondrodysplasia)
- 2nd and 3rd trimester
- CNS malformation and hemorrhage, respectively
- Generally
- Nasal hypoplasia
- Bone deformities
- Abortion
- Fetal hemorrhage
- Ophthalmologic abnormalities
Effects of methotrexate
- Clover-leaf skull
- Wide nasal bridge
- Low set ears
- Micrognathia
- Limb abnormalities
Effects of radioiodine
- Irreversible hypothyroidism
- Risk for thyroid cancer
Effect of lithium
Ebstein anomaly
- Atrialization of the right ventricle
- Memory aid:*
- LIThium – _L_ow _I_mplantation _T_ricuspid
Most potent teratogen
- Teratogen
- Effect
- Teratogen
- Retinoids (isotretinoin)
- Effect
- Cranial-neural crest defect
Preformed vitamin A
- Form
- Level that may cause defect
- Form
- Retinol
- Level that may cause defect
- > 10,000 mIU/day
Neonatal effects of SSRI
- Neonatal abstinence syndrome
- jitteriness or shivering
- increased muscle tone
- feeding or digestive disturbances
- irritability or agitation
- respiratory distress
- Persistent pulmonary hypertension of the newborn
Summary:
- Not considered a teratogen
- Neonatal effects, so most probably, signs of withdrawal
Paroxetine fetal effects
ASD and VSD
- Memory aid:*
- _S_SRI _P_aroxetin causes _S_hunt _P_roblems
T/F. Antipsychotics are considered teratogenic
False; but they cause EPS and withdrawal symptoms
Effect of ACE inhibitors
Fetal renal damage
Effect of anti-epileptic drugs
Neural tube defects
- Note:*
- Anti-epileptic drugs are folate antagonists
Effect of phenytoin
Fetal hydantoin syndrome
Effect of OHAs
Neonatal hypoglycemia
Effects of barbiturates
Neonatal dependence
Effect of misoprostol
Mobius sequence, a rare neurological disorder characterized by weakness or paralysis (palsy) of multiple cranial nerves, most often the 6th (abducens) and 7th (facial) nerves
Memory aid:
- Misoprostol
- Mobius sequence
- Multiple CN problems
Effects of penicillamine
Cutis laxa, a group of rare connective tissue disorders in which the skin becomes inelastic and hangs loosely in folds
Effects of methimazole
Aplasia cutis congenita
Effect of fluoroquinolones
Cartilage damage
Memory aid:
- _C_iprofloxacin
- _C_artilage
Effects of alkylating agents
Absence of digits, multiple anomalies
Effects of cocaine
- Low birth weight
- Preterm birth
- IUGR
- Placental abruption
Memory aid:
- COcaine is a
- COnstrictor
Effects of smoking
- Low birth weight (leading cause in developed countries)
- Preterm labor
- Placental problems
- IUGR
- SIDS
Methylmercury
- Effect
- Sources
- Effect
- Neurotoxicity
- Sources
- Swordfish
- Shark
- Tilefish
- King mackerel
X-rays
Microcephaly, intellectual disability
