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Psychology of Human Growth and Development
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cognitive development part 2
Psychosocial development
Development of emotions
Depression
Language development
Cognitive development part 1
Perceptual development part 2
Memory
Development of attachment
Introduction
Nature versus nature
Introduction to developmental theories
Prenatal development and chromosomal abnormalities
Prenatal development and teratogens
Brain development
Motor development
Physical growth
Perceptual development

Lecture 5

 

Prenatal Development and Teratogens

 

What are Teratogens?

 

An agent, such as a virus, a drug, or radiation, that causes malformation of an embryo or fetus

 

Vulnerability

                  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.

                  structural defects if teratogenic agent occurs when critical organs are being formed

                  Functional 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. (1995, 1999b),

Prenatal tobacco exposure was significantly related to:

Reduced birth weight,

Birth length,

Head circumference,

Chest circumference.

 

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 mothers had

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.

 

 

2. Alcohol

 

Effects of moderate drinking on prenatal development

 

e. g. Jacobson and Jacobson (1996)

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 (1993)

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

 

3. Disease

 

Effect of Gonorrhea on unborn infant

 

Turner and Rubinson (1993)

Left untreated can lead to cardiovascular difficulties,

Arthritis,

Sterility

pelvic inflammatory disease - this can cause an ectopic pregnancy (Zygote implants itself in fallopian tubes rather than the uterus)

 

Effect of herpes on unborn infant

Healy (1995)

Herpes (Viral infection)

 

Disease can cause

blindness,

motor abnormalities,

mental retardation,

neurological disorders.

 

Effect of aids on unborn infant

 

children with AIDS suffer

neurological impairments,

delays in mental and physical development,

structural deformities (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 functioning

 

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

 

Smith (1995)

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

 

      vitamins and proteins related to increased rates of miscarriages, stillbirths and infant mortality.

 

      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.

 

      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

 

      e. g. Black et al (2004) Zinc supplementation on newborn after poor nutrition mixed results

 

Depression and prenatal development

See Bonari et al (2004) literature review

 

      untreated depression may have associated obstetric complications.

 

      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

 

Aspirin

 

e. g. Schnoll (1986) and Vorhees and Mollnow (1987)

if taken in high doses by pregnant women may produce blood disorders in offspring.

 

DES Diethylstilbestrol

 

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.

 

(Nevin 1988)

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.

 

Thalidomide

 

e.g. Moore and Persaud (1993)

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

 

Marijuana

 

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 cry.

No evidence of long term adverse effects on infant development

 

Cocaine

 

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

 

Lead

 

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.

 

 

 

TPS102