An agent, such as a
virus, a drug, or radiation, that causes malformation of an embryo or fetus
greatest in first 4 to 8 weeks of gestation
peaks in 5th week of gestation
For Zygote tiny mass so defenseless that it dies
if exposed so would have spontaneous abortion.
defects if teratogenic agent occurs when critical organs are being formed
problems or stunted growth if occurs later.
1. Effects of Smoking
Paternal smoking effect on prenatal development
E.g. Sorahan, Lancashire, Hulten, Peck and Stewart (1997)
Fathers who smoked a pack or more of cigarettes a day had a 43% increased risk of having a child with cancer.
They concluded that - men who smoke may transmit risk to infant.
Maternal smoking effect on prenatal development
e. g. Cornelius et al.
tobacco exposure was significantly related to:
Reduced birth weight,
Gender differences in smoking effects on fetuses
e. g. Zaren et al (2000)
Reported that the male
fetus might be more adversely affected than the female fetus.
Boys born to heavy-smoking
Greater weight reductions,
Lower fat accretions,
Smaller head circumferences
Effect of Quitting on growth and cognitive development
e. g. Fox et al. (1990)
Children of women who
quit smoking during pregnancy were heavier and taller than those of women who did not quit.
Effects of moderate drinking on prenatal development
e. g. Jacobson and Jacobson
Pregnant woman's moderate
social drinking (glass of beer or wine per day) can cause abnormal behaviour patterns in her baby
Effect of paternal drinking on prenatal development
e. g. Cicero (1994)
Fathers who drink heavily
ay sustain genetic damage that leads to birth defects in their children.
Effect of Binge drinking
One of the strongest
predictors of later neurodevelopment deficits in children with alcohol-induced damage.
Alcohol and hormones
e. g. McGivern and Riley
They suggest that at
least in rats, prenatal alcohol exposure may result in the "feminization" of behavior in males and in the "masculinization"
of behavior in females.
Effect of Alcohol withdrawal on fetus
e. g. Beattie (1986)
Reported the case of a newborn who exhibited signs of AW-including tremors, irritability, frequent mouth movements,
and vomiting-between 24 and 48 hours after delivery.
Smoking and Drinking
Smoking and drinking
worse than one or the other
Effect of Gonorrhea on unborn infant
Turner and Rubinson
Left untreated can lead
to cardiovascular difficulties,
disease - this can cause an ectopic pregnancy (Zygote implants itself in fallopian tubes rather than the uterus)
Effect of herpes on unborn infant
Herpes (Viral infection)
Disease can cause
Effect of aids on unborn infant
children with AIDS suffer
delays in mental and
(small head, slanted eyes) and
high vulnerability to
disease leading to early death.
Children survive less
than 9 months after diagnosis. and less than that if under age of one.
4. Maternal Factors
children of adolescent mothers and normal cognitive development, emotional
Sommer, et al 2000
Less than 30% of the
entire sample--which was generally healthy at birth--showed normal cognitive development, emotional functioning, and adaptive
behavior at three years of age.
Personal habits of young mothers
teenagers more likely
to have unhealthy personal habits (e.g. drug abuse) and so are more likely to have pregnancy complications like toxemia and
infants with low birth weight.
Effect of dietary deficiency
Ø vitamins and proteins related to increased rates of miscarriages, stillbirths
and infant mortality.
Ø impairment of intellectual development most marked when mother's malnutrition
was severe, long lasting and sustained after childbirth so continued ill effects on the child.
Ø No long lasting intellectual deficits if mother's previously well nourished
- go through short term period of famine e.g. coz of war - and then child has a good diet
Ø e. g. Black et al (2004) Zinc supplementation on newborn after poor nutrition
Depression and prenatal development
See Bonari et al (2004)
Ø untreated depression may have associated obstetric complications.
Ø The prevalent idea is that psychopathological symptoms during pregnancy have
physiological consequences for the fetus.
thyroid deficiency in pregnant women and how well their children subsequently
do in tests of language, intelligence, and motor coordination.
e. g. Haddow (1999)
The children of the
62 women judged hypothyroid did less well on all lS tests, even though their own
thyroid activity was normal.
On average, their IQ
scores were four points lower than those of the control children.
IQ scores were an average
of seven points lower in the offspring of the 48 women who had no treatment for hypothyroidism during pregnancy
5. Medicinal drugs
e. g. Schnoll (1986)
and Vorhees and Mollnow (1987)
if taken in high doses
by pregnant women may produce blood disorders in offspring.
e.g. Herbst (1981),
Prevent pregnant women
from miscarrying in 1947-1964
male offspring - abnormalities
of reproductive tract, fertility problems and increased risk of cancer of the testes.
Female offspring - developed
vaginal abnormalities and cancer of the cervix in adolescence.
Linn et al (1988)
High rate of problems
in pregnancy, spontaneous abortion and delivered babies with low birth weight.
e.g. Moore and Persaud
deformations of the
eyes, nose, ears cleft plate, facial palsy and fusing of fingers and toes.
dislocations of the hip joint and malformations of the heart and digestive and genitourinary tract.
6. Illegal drugs
e. g. Dreher, Nugent
and Hudgins (1994) and Lester and Dreher (1989) and Zuckerman and Breshahan (1991)
prenatal exposure to
marijuana leads to infants reduced weight and size, short term changes in behaviour e.g. increased startle and a high pitched
No evidence of long
term adverse effects on infant development
e. g. Lester (1991)
effect of maternal cocaine
use - children tend to be impulsive, highly distractable and difficult to control and to have problems in language development
as they grow older.
7. Environmental effects
e. g. Bellinger et al.
(1991) and Dietrich, Berger, Succop, Hammond and Bornschein (1993)
exposure to lead during
pregnancy can lead to prematurity, low birthweight, brain damage and
physical defects as
well as long term problems in cognitive and intellectual functioning.
Father’s exposure to toxins
e. g. Bentur and Koren
(1991) and Stone (1992)
Father's exposure to
toxin's harmful effect on developing fetus.
Men who work in occupations
that expose them to toxic substances e.g.: radiation, mercury, lead may develop chromosomal abnormalities that may affect
their fertility or may increase the risk that their pregnant wives will miscarry or will bear infants with birth defects.