Teratogens and their effects on unborn babies, newborn babies, and
developmental milestones
-- Fetal Hydantoin Syndrome,
caused by prenatal exposure to
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.
-- 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
an unusually small head, and growth deficiency in some infants
infected with HIV.* Such craniofacial abnormalities have included a
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
, and other musculoskeletal abnormalities.
-- 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 delay). In addition, distinctive skin
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
. There may also be abnormalities of the part of the nervous
system that controls involuntary functions (autonomic nervous system) such as
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 intellectual disability, 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
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.
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
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.
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
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.
--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, intellectual disability,
and generalized growth retardation.
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.
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
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
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.

However, many
agents can exhibit teratogenic effects under certain circumstances.
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)


(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
delay, 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)

(Anticonvulsant; mood stabilizer.) (Neural tube defects [such as
spina bifida])

Cigarette smoking (5)

Cocaine (7)

(Maternal infection.) (Growth and developmental delay,
microcephaly, hearing loss, ocular abnormalities)

Diethylstilbestrol (Used to prevent miscarriage.) (Vaginal adenosis [abnormality
and increased risk for cervical cancer], adenocarcinoma [glandular], cervical


Herpes (Primary) (10)
Herpes (Active) (10)
(Vertical transmission at delivery)

Hydantoin (1)

(Maternal disorder) (Intrauterine growth delay)

Hyperthermia (Neural tube defects)

Hyperthyroidism (Both maternal disorders.) (Goiter, growth and developmental

Hypothyroidism (Goiter, growth and developmental delay)

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 intellectual disability, 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)

(Chemical found in some seafood.) (Cerebral atrophy, spasticity,
intellectual disability)

Penicillamine (Rheumatoid arthritis treatment.)  (Cutis laxa [connective tissue
disorder where the skin lacks elasticity])

Phenylketonuria (Maternal disorder.) (Pregnancy loss, microcephaly, intellectual
disability, facial dysmorphism, congenital heart defects)

Polychlorobiphenyls (PCB) (Ingested.) (Chemical) (Low birth weight, skin

Radiation (Growth and developmental delay, microcephaly)

Rubella (9)

(Antibiotic.) (Hearing loss)

Syphilis (STD.) (Abnormal teeth and bones, intellectual disability)

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)

(Cleft palate, other congenital malformations)

Trimethadione (Anticonvulsant.) (Developmental delay, dysmorphic facial

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)