fetal development slides

1st trimester for mother

• pregnancy tests measure HCG in urine/blood

• morning sickness - nausea and vomiting at any time of day (70%-90% of women)

• begins 4-6 weeks after conception, peaks at 8-12 weeks

• enlarged tender breasts, darkened areolas, enlarged nipples, tiredness

couvade syndrome

men have the same symptoms as women in the first trimester, have physical symptoms indicating pregnancy

2nd trimester for mother

• mothers can feel movements (1st quickening)

• emotional attachment

• abdomen expands, stretch marks

• breasts swell and sometimes leak

• appetite increase

3rd trimester for mother

• movement is difficult

• back pain, shift in center of gravity, weight gain (15-40 lbs), frequent urination 

• indigestion, heartburn, gas, constipation

• sleeping is uncomfortable

• navel pushes out

teratogens

• environmental factors other than genetic/chromosomal that may cause birth defects

principles of teratogens

• susceptibility - different specifies affected differently, testing on different mammals, how sensitive we are

• dose response - more exposure, worse the effect

• sleeper effects - effects may take many years to show

• critical periods

teratogen types 

1. diseases

2. inadequate diet

3. maternal stress

4. drugs

5. environmental hazards

(dragons in mountains devour everything) lol

diseases may cause…

microencephaly, mental retardation, blindness, deafness, miscarriage

rubella virus

babies born blind, deaf, intellectually impaired

complications: diseases

• herpes - death/neurological damage

• gonorrhea and chlamydia - blindness

• syphilis - something bad :(

inadequate diet/malnutrition may cause…

• prematurity, low birth weight, prolonged labor, more dental problems, less developed CNS

• a GOOD diet has lots of folic acid

causes of maternal stress

1. more negative attitudes towards pregnancy

2. feelings of intense inadequacy

3. previous negative pregnancy

4. no spouse

5. men offer little emotional support OR were abusive in some way

drugs may cause… 

miscarriages, low birth weight, hyperactivity, susceptibility to health problems, brain damage, small babies

(skipped)

what does smoking do to baby?

• low birth weights, miscarriages, ectopic pregnancy, preterm births, infant mortality

• decrease respiratory function

• increase risk of sudden infant death syndrome

what does cocaine and crack do to the baby?

• diminished growth during pregnancy

• preterm birth, smaller head circumference

• sensory motor and behavioral defects, irritability, disorientation

• later learning and behavioral disorders

what does alcohol do to the baby? 

• fetal alcohol syndrome

• physical deformities, mental retardation, CNS damage and maybe other organ damage

• moderate consumption of alcohol leads to fetal alcohol effect (emotional problems and inability to cope in school)

• breast feeding leads to low rate of motor development and coordination

what are some examples of environmental hazards?

• toxins

• lead

• mercury

• radiation

• carbon monoxide

• tuna ??

(three little mice ride cows today)

what happens in each trimester of fetus development?

• happens weeks 9-40, most development happens in 2nd and 3rd trimester

• 2nd trimester - organs come “online”

• 3rd trimester - mostly growth and myelin formation, senses work, becomes viable

week 9 of fetus development

• iris of eye and finger nails appear

• squint, swallow, move tongue, make fist if you stroke palm

week 10 of fetus development

• brain has same structure it will be at birth

• in the next week, body systems begins functioning

week 11 of fetus development

• teeth have formed

• pancreas is secreting insulin

• villi (finger like projections that absorb nutrients) are developing in baby’s intestines

week 12 of fetus development

• baby sucking thumb vigorously

• practices breathing the amniotic fluid into and our of his lungs to develop them

• kidneys are making urine

• baby’s gender can be observed

gender identification and the weeks they appear

1. penis at 17 weeks — vagina at 21 weeks

2. testicles at 13 weeks — ovaries at 11 weeks

3. testosterone produced by testicles — ovaries begin producing ova

what weeks are the 2nd trimester?

14-28

what does the baby do or look like in the 2nd trimester?

• skin is covered with vernix (white cheese substance ew) which protects and lubricates skin

• lanugo (fine hair) covers body

• fetus swallows amniotic fluid

• kidneys produce pee which goes into amniotic fluid

what happens in the 3rd trimester?

• 90% of babies survive if born now, 7-9 months

• final refinements being made to organs

• gaining 0.5 lbs per week

• ready to be born weeks 38-40

sensation

• detection of stimulation

• involves active sense

• definitely presents in prenates

perception

• interpretation of stimulation

• involves active brain (what is there? what does it mean?)

• limited and somewhat unknown in prenates

how do we measure sensation and perception?

• problem: we can’t ask prenate what they sense and perceive

• so, we observe their behaviors

• measures body language like smiling or crying

what are the senses? list them

• vision

• audition (hearing)

• gustation (taste)

• olfaction (smell)

• tactile (touch)

how is vision at birth?

• least developed sense

• requires more brain and muscle development

• poor tracking of objects, color discrimination, depth perception

what are newborn’s visual preferences?

• faces

• complex images

• 3D images

• novel images

• high contrast objects

how is hearing at birth?

• well developed at birth, can hear in the mother

• can distinguish different voices, languages, and localize sound

• poor hearing low pitch sounds and short duration sounds

how is taste at birth?

• can distinguish basic tastes

• sensitive to heavy spiciness and seasoning

• varied foods help taste to develop and prevent fussy eaters

how is smell at birth?

• well developed at birth

• very sharp and sensitive

• can turn to own mother’s smell at birth but not dad

how is a baby’s touch at birth?

• well developed at birth

• can detect differences on skin in temperature, texture, and pressure

• very good for baby’s health and brain development to be stroked

chorionic villi sampling

• small tube inserted through the vagina and cervix and removes some hair like cells from the chorion

• viable test from weeks 8-10

• detect chromosomal problems (down syndrome)

amniocentesis

• hallow needle through abdomen, uterus, and amniotic sac to withdraw amniotic fluid

• viable after 14th week

• 1% chance of spontaneous abortion

fetoscopy

• tube of fiber optic strands inserted into the amniotic sac to take fetus blood sample

• damage to fetus possible

sonogram/ultrasound

• noninvasive, sound waves to create image of fetus

• detects malformation of skeletal system, cannot detect genetic defects

• 2D or 3D

fetal surgery process

• catheterize fetus to drain urine

• repairing hernia of diaphragm

• bone marrow transplant

• corrected spina bifida

• future: in utero gene therapy