Prenatal Development

increased

Have average maternal age and average number of children increased or decreased since the 1960s?

late teens

When is fertility greatest?

increase

Does average maternal age increase or decrease with a college degree?

higher

Is average maternal age higher or lower in populated cities compared to rural areas?

zygote/germinal, embryo, fetus

3 periods of prenatal development

zygote/germinal

period of prenatal development that begins with conception and ends with implantation of the egg in the uterus; cell division and multiplication occurs

2 weeks

length of zygote/germinal period

embryo

period of prenatal development that begins with implantation and ends at 8 weeks gestation

embryo

period of prenatal development when body parts and organs take shape, cardiac activity begins, CNS begins to develop

23 days

Cardiac activity begins after about how many days?

fetus

period of prenatal development when growth and refinement of body parts occurs, significant CNS/brain development/myelination occurs, can detect light and sounds

5 months

The fetus can detect light and sounds after how long?

fetus

period of prenatal development that takes place from 8 weeks to birth

40 weeks (9 months)

typical gestation period length

age of viability

gestational age at which there is potential of the fetus to survive outside the uterus after birth

22 weeks

current age of viability (although very few fetuses will actually survive at this age)

limit of viability

gestational age at which the fetus has a 50% chance of long-term survival outside the uterus after birth

24 weeks

current limit of viability (although incidence of major disabilities remains high at this point)

teratogens

environmental agents that increase the risk of damage to the developing organism prenatally

teratogens

examples of these include alcohol, cocaine, mercury, thalidomide, radiation, and nicotine

fetal alcohol syndrome (FAS)

physical and cognitive abnormalities in children caused by a pregnant woman's heavy drinking; symptoms include intellectual disability, underdeveloped motor skills, short attention span, difficulties regulating emotions, speech/language difficulties, etc.

effects

the ___________ of teratogens depend on the amount of exposure, timing of exposure, and individual differences in the vulnerability of the organism

critical periods

organism is most vulnerable during these periods of prenatal development when rapid growth of particular body parts/organ systems occurs

thalidomide

drug taken in the 50s to control morning sickness, which is most severe in 2nd and 3rd month when the greatest development of the fetus occurs; caused babies to be born with severe malformations