chapter 3 - pregnancy and prenatal dev

cephalocaudal principle

“head to tail”, D that starts at head and then works from top to bottom, happens at same time as proximodistal principle

proximodistal principle

“near to far”, D starts from center and works outward, happens at same time as cephalocaudal principle

germinal stage

conception-2 weeks, when one cell divides over and over, implantation happens at end of this stage, by 2 weeks a placenta, umbilical cord, and fluid have formed, only 10-20% of fertilized eggs implant

embryonic stage

2-8 weeks, key time where major organs and body system develops, embryo sensitive to environment, 80% miscarriages happen during first 3 months due to chromosomal abnormalities, estimate ¼ known pregnancies are miscarried

fetal stage

8-40 weeks, “finishing touches” D and baby grows 20x in length

fetal hearing

babies can respond to sound and vibration

fetal “learning”

babies like higher pitched voices and can distinguish mom’s voice (most soothing) as well as dad’s, can even differentiate language

nutrition and prenatal environment

should expect to gain 25-30lbs, mother’s diet matters, ie. need enough folic acid

teratogens and prenatal environment

any E factor that interferes with normal D and can cause a birth defect

teratogens: medical drugs

no meds should be taken unless considered essential

teratogens: alcohol

prenatal exposure is leading cause of preventable birth defects and intellectual disability, FAS (fetal alcohol syndrome) babies have slight physical differences and longterm L/intellectual disability