Teratogens and their effects on unborn babies,
newborn babies, and developmental milestones
1. DILANTIN
-- Fetal Hydantoin Syndrome, caused
by prenatal exposure to the anticonvulsant drug
phenytoin (Dilantin).
The SYMPTOMS of this disorder may include
abnormalities of the skull and facial features, growth
deficiencies, underdeveloped nails of the fingers
and toes, and/or mild developmental delays. Other
findings occasionally associated with this syndrome
include cleft lip and palate, having an unusually small
head (microcephaly) and brain malformations with
more significant developmental delays.
2. MATERNAL AIDS
-- AIDS Dysmorphic Syndrome
The term "AIDS dysmorphic syndrome" or "HIV
embryopathy" has been used by some researchers to
describe specific facial malformations (i.e., craniofacial
dysmorphism), an unusually small head, and growth
deficiency in some infants infected with HIV.* Such
craniofacial abnormalities have included a prominent,
boxlike forehead; large, wide eyes; a flattened nasal
bridge; and an unusually pronounced philtrum, which is
the vertical groove in the center of the upper lip.
However, many investigators have since questioned the
significance of these observations. Such researchers
indicate that there is lack of evidence for characteristic
craniofacial malformations in infants who acquired HIV
infection from their mother before, during, or shortly after birth
(i.e., perinatally).
3. VALPROIC ACID (dalpro, depakene,
depakote, depakote sprinkle, divalproex, epival,
myproic acid)
--Fetal Valproate Syndrome, or
Fetal Anti-convulsive Syndrome
Fetal Valproate Syndrome is a rare congenital disorder
caused by exposure of the fetus to valproic acid during the
first three months of pregnancy. Valproic acid is an
anticonvulsant drug used to control certain types of
seizures in the treatment of epilepsy. A small percentage
of pregnant women who take this medication can have a
child with Fetal Valproate Syndrome. The exact prevalence
of this condition remains to be established. Symptoms of
this disorder may include spina bifida, distinctive facial
features, and other musculoskeletal abnormalities.
4. MATERNAL CHICKEN POX
-- Congenital Varicella Syndrome
Congenital Varicella Syndrome is an extremely rare disorder in
which affected infants have distinctive abnormalities at birth
(congenital) due to the mother's infection with chickenpox (maternal
varicella zoster) early during pregnancy (i.e., up to 20 weeks
gestation). Affected newborns may have a low birth weight and
characteristic abnormalities of the skin; the arms, legs,
hands, and/or feet (extremities); the brain; the eyes; and/or,
in rare cases, other areas of the body. The range and severity
of associated symptoms and physical findings may vary greatly
from case to case depending upon when maternal varicella zoster
infection occurred during fetal development. In many cases,
newborns with Congenital Varicella Syndrome may be abnormally
small and have a low birth weight due to abnormal growth
delays during fetal development (intrauterine growth
retardation). In addition, distinctive skin abnormalities are often
present. Certain areas of the skin may consist of thickened,
overgrown (hypertrophic) scar tissue (cicatrix), and
surrounding skin may appear abnormally hardened
(indurate), red, and inflamed (erythema). Such cicatrix scarring
typically occurs on one or more of the arms and/or legs, which may
also be malformed, underdeveloped (hypoplastic), and
abnormally shortened (reduction deformities). Affected infants
may also exhibit incomplete development (hypoplasia) of
certain fingers and/or toes (rudimentary digits). In some
cases, newborns with Congenital Varicella Syndrome may have
abnormalities of the brain such as degeneration of the outer
portion of the brain (cortical atrophy) and/or abnormal
enlargement of cavities of the brain (dilated ventricles
[ventriculomegaly]). There may also be abnormalities of the part
of the nervous system that controls involuntary functions (autonomic
nervous system) such as damage to or abnormalities of certain
nerve fibers (sympathetic nerve fibers) that pass from the
spinal cord to the neck and/or pelvic area. Some affected
infants and children may also exhibit abnormal smallness of the
head (microcephaly), delays in the acquisition of skills
requiring the coordination of mental and physical activities
(psychomotor retardation), varying degrees of mental
retardation, and/or learning disabilities. In some cases,
characteristic eye (ocular) abnormalities may also be present
including loss of transparency of the lenses of the eyes
(cataracts); abnormal smallness of one or both eyes
(unilateral or bilateral microphthalmia); involuntary, rapid,
side-to-side movements of the eyes (pendular nystagmus);
and/or inflammation and scarring of certain membranes of
the eyes (chorioretinitis and chorioretinal scarring). Such
ocular abnormalities may result in varying degrees of visual
impairment. In rare cases, newborns with Congenital Varicella
Syndrome may have additional abnormalities associated with
the disorder.
5. MATERNAL SMOKING
Carbon monoxide and nicotine in tobacco both reach the baby very easily
through the placenta. Both of these can cause problems with the baby's
growth and development before birth. Carbon monoxide and Nicotine
reduce the amount of oxygen available in the mother's blood, which can
affect the development and size of the baby.
Smoking can cause problems in pregnancy such as miscarriage, stillbirth,
placental problems, bleeding during pregnancy and premature birth.
Babies practice breathing movements while in the womb. It has been shown
that cigarette smoking can disrupt these breathing movements. Research
has also shown that babies of smokers are generally below the average
birth weight and that these babies can develop complications such
as infections and breathing problems during the first weeks of life.
Some research has indicated that smoking may increase the risk of
sudden infant death syndrome.
7. MATERNAL COCAINE USE
Considerable research into the effects of cocaine use in pregnancy indicates that
cocaine may cause miscarriage, stillbirth, bleeding, abruptio placenta and
premature birth. It also indicates that cocaine use may have an effect on the
baby's growth and development before, and even after birth. Cocaine increases
the heart rate in both the mother and baby and the supply of oxygen and
blood to the baby is reduced, which makes it more likely that the baby will
be small and grow slowly. Several cases of bleeding in the brain have been
reported in babies whose mothers were dependent on cocaine. A number of fetal
abnormalities have been reported concerning the use of cocaine during
pregnancy. If cocaine is used close to the birth the baby may be born excessively
active and appear distressed and restless. Withdrawal symptoms can
occur in the babies of mothers who use cocaine regularly. These
symptoms appear similar to those of adults experiencing withdrawal and
can include sleepiness and lack of responsiveness.  
6. MATERNAL MARIJUANA USE
Women who smoke marijuana often smoke it with tobacco and therefore there will
be risks to the baby from tobacco smoke. THC (Tetrahydrocannabinol) is the active
ingredient in marijuana and does cross the placenta. It is stored in the amniotic fluid
that the baby lives in prior to birth. It is possible that marijuana use in pregnancy is
associated with premature labor and small babies, with all the associated
dangers of low birth weight including infections and breathing problems.
8. MATERNAL CAFFEINE INGESTION
A stimulant found in colas, coffee, tea, soft candies, chocolate, cocoa, and
over-the-counter and prescription drugs, caffeine has been a controversial topic in
pregnancy nutrition for more than a decade. A 1980 study by FDA found that
caffeine, when fed to pregnant rats, caused birth defects and delayed skeletal
development in their offspring. At that time, although the human implications were
unknown, FDA advised pregnant women to eliminate caffeine from their diets.
Since then, more studies have been done to determine the effects of caffeine on the
fetus. A study of women in Costa Rica, where coffee consumption is high, showed a
significantly lower birth weight for infants and a lower concentration of iron in
mothers who were coffee drinkers. This report indicated that maternal coffee intake
may also contribute to maternal and infant anemia.
9. MATERNAL RUBELLA
--Congenital Rubella Syndrome
Transplacental infection of the fetus with rubella usually in the first
trimester of pregnancy, as a consequence of maternal infection,
resulting in various developmental abnormalities in the newborn
infant. They include cardiac and ocular lesions, deafness,
microcephaly, mental retardation, and generalized growth
retardation.
10. MATERNAL HERPES
A pregnant woman who develops a first episode of genital herpes
can pass the virus to her fetus and may be at higher risk for
premature delivery. Newborns rarely become infected with
herpes (neonatal herpes); however, half of those who become
infected either die or suffer neurological damage. With early
detection and therapy, many serious complications can be
lessened. The newborn's chances of infection depend on whether
the mother is having a recurrent or a first outbreak. If the mother is
having her first outbreak at the time of a vaginal birth, the
baby's risk of infection is approximately one in three. If the
outbreak is a recurrence, the baby's risk is very low.
Because of the danger of infection to the baby, however, the
physician will perform a cesarean section if herpes lesions
are detected in or near the birth canal during labor. Some
physicians also perform a viral culture at the time of delivery to
detect shedding in women known to have had genital herpes
outbreaks in the past. A baby born with herpes can develop
encephalitis (inflammation of the brain), severe rashes, and
eye problems. Acyclovir can greatly improve the outcome for
babies with neonatal herpes, particularly if they receive immediate
treatment.
11. MATERNAL TOXOPLASMOSIS
Toxoplasmosis is an infection with the parasite Toxoplasma gondii. If a
woman becomes infected during pregnancy the infection may pass
through the placenta to the developing fetus. Women at risk of acute
infection and secondary transmission to their fetus are those who are
antibody-negative (were not previously exposed to T. gondii) and
whose culinary practices include the use of raw, previously unfrozen
meat (e.g., some women of French or African descent, Inuit women)
and women who travel to these regions during pregnancy, as well as
women who handle kittens or previously uninfected cats and/or kitty
litter during pregnancy.
Transplacental transmission following maternal infection may occur
throughout pregnancy, although it is more common later in pregnancy.
The severity of infection is inversely related to the gestational age at
which transmission occurs.
Infection may result in symptomatic neonatal disease, either
generalized or neurological; symptomatic disease occurring in
the first months of life, usually neurological; sequelae or relapse
later in childhood of a previously unrecognized infection, usually
chorioretinitis; and subclinical infection. The vast majority of infants
have subclinical infection. 40% of symptomatically infected infants show
abnormalities in brain scans (e.g., computed tomography [CT]
scan).
Maternal Infection. A positive antibody test in pregnancy is insufficient
evidence of the need for therapy: 10% to 40% of pregnant women have
toxoplasmosis-specific antibody due to remote infection, depending on
culinary practices, exposure to cat excreta, country of birth, etc.
Furthermore, toxoplasmosis-specific immunoglobulin (Ig) M antibody
may persist for more than one year, and in these situations may well
have anteceded any risk of fetal disease.
Once toxoplasmosis is diagnosed in the mother, treatment with
spiramycin is recommended to prevent transplacental transmission of
toxoplasmosis. While spiramycin is not teratogenic, it does not cross
the placenta.
Fetal Infection. Infection of the fetus follows either symptomatic or
asymptomatic infection in pregnancy. Women with a history of ingestion
of raw meat in pregnancy, who travel to a region with high rates of
infection (e.g., France) or who acquire a kitten and handle kitty litter
should be tested.
When fetal infection is confirmed, generally after 20 weeks’ gestation,
the combination of pyrimethamine, sulphadiazine and folinic acid is
used.
Newborn Infection. The diagnosis of congenital toxoplasmosis in the
newborn infant should be considered in the presence of positive
maternal serology and/or suggestive clinical findings often associated
with abnormalities of ophthalmological examination,
cerebrospinal fluid analysis and cranial CT scan.
Management of congenital toxoplasmosis should be carried out in
conjunction with a colleague experienced in this area. The treatment of
choice for congenital toxoplasmosis in the neonate is the combination
of pyrimethamine, sulphadiazine and folinic acid administered for one
year. These children need to be followed carefully for evidence of
myelosuppression secondary to medication, appearance or
progression of retinal disease, development of ventricular
obstruction and developmental delay. Multidisciplinary follow-up
care, appropriate to the deficit and with attention to auditory function,
is required. Breastfeeding by an infected mother provides no risk to her
infant. These infected children are not contagious.
For a list of known
teratogens, click
HERE.

For a movie or two
about brain
development and
teratogens, Go HERE
Teratogen:
1. agents that cause malformations in a developing
embryo;
2. agents that cross the placental barrier and
cause or increase the incidence of physical
malformations and behavioral and cognitive
deficits;
3. any medication, chemical, infectious disease, or
environmental agent  that might interfere with the
normal development of a fetus & result in the loss
of a pregnancy, a birth defect, or a pregnancy
complication.

Usually, an increased prevalence of a
particular birth defect leads to the
discovery of a teratogenic agent.

THERE ARE NO ABSOLUTE
TERATOGENS ... However, many agents
can exhibit teratogenic effects under certain
circumstances. The DOSE and TIME OF
EXPOSURE often determine the severity of
the damage and the type of defect that
occurs.
A couple of known human
teratogens:

ACE inhibitors (treats hypertension and congestive heart
failure) (renal dysgenesis [abnormal or defective development
of the kidneys], oligohydramnios sequence [deficiency of
amniotic fluid during pregnancy], skull ossification defects)

alcohol (go here)

aminopterine (chemotherapy) and methotrexate  (treats
arthritis and rheumatic [us. bones and joints, etc.] conditions)
(pregnancy loss, hydrocephalus [excess cerebrospinal fluid in
the ventricles of the brain], low birth weight, dysmorphic facial
features)

androgens and high doses of nor-progesterones
(steroid; contraceptive) (masculinization of external female
genitalia)

anticancer drugs (pregnancy loss, neural tube defects,
hydrocephalus, growth retardation, cardiovascular
malformations)

antithyroid drugs (hypothyroidism, goiter)

autoimmune disorders (2) (maternal disorder) (congenital
heart block, pregnancy loss, chronic illness, failure to thrive,
recurrent diarrhea, weight loss)

caffeine (8)

carbamazepine (anticonvulsant; mood stabilizer) (neural
tube defects [such as spina bifida])

cigarette smoking (5)

cocaine (7)

cytomegalovirus (maternal infection) (growth and
developmental retardation, microcephaly, hearing loss, ocular
abnormalities)

diethylstilbestrol (used to prevent miscarriage) (vaginal
adenosis [abnormality and increased risk for cervical cancer],
adenocarcinoma [glandular], cervical erosion)

herbicides

herpes (primary) (10)
herpes (active) (10) (vertical transmission at delivery)

hydantoin (1)

hypertension (maternal disorder) (intrauterine growth
retardation)

hyperthermia (neural tube defects)

hyperthyroidism (both maternal disorders) (goiter, growth
and developmental retardation)
hypothyroidism (goiter, growth and developmental
retardation)

industrial solvents

insulin dependent diabetes mellitus (maternal
disorder)(congenital heart defects, caudal deficiency, neural
tube defects, limb defects, holoprosencephaly [facial defects
that occurred during fetal development], pregnancy loss)

iodine (a deficiency can cause mental retardation, spasticity,
deafness, hypothyroidism [underactive thyroid -- too little
thyroxine])

isotretinoin (acne treatment) (pregnancy loss,
hydrocephalus, other central nervous system defects, small or
absent thymus [a gland], microtia [abnormally small ear] or
anotia [absence of ear], conotruncal heart defects)

lead (pregnancy loss, central nervous system damage)

lithium (treats the manic phase of bipolar disorder) (Ebstein
anomaly [heart])

marijuana (6)

methylmercury (chemical found in some seafood) (cerebral
atrophy, spasticity, mental retardation)

penicillamine (rheumatoid arthritis treatment)  (cutis laxa
[connective tissue disorder where the skin lacks elasticity])

phenylketonuria (maternal disorder) (pregnancy loss,
microcephaly, mental retardation, facial dysmorphism,
congenital heart defects)

polychlorobiphenyls (PCB) (ingested) (chemical) (low
birth weight, skin discoloration)

radiation (growth and developmental retardation,
microcephaly)

rubella (9)

streptomycin (antibiotic) (hearing loss)

syphilis (STD) (abnormal teeth and bones, mental retardation)

tetracycline (antibiotic; used to treat acne) (stained teeth,
enamel hypoplasia [incomplete or defective development)

thalidomide (used to treat morning sickness) (limb reduction,
ear anomalies)

toxoplasmosis (11)

tranquilizers (cleft palate, other congenital malformations)

trimethadione (anticonvulsant) (developmental retardation,
dysmorphic facial features)

valproic acid (3)

varicella (4)

Venezuelan equine encephalitis (maternal
infection)(Central nervous system damage, cataracts,
pregnancy loss)

warfarin (anticoagulant) (nasal hypoplasia, stippled
epiphyses [abnormal growth at the epiphyses), central nervous
system defects)