Fetal Development

Question 1

Amniotic Fluid

Answer 1

• 98% water
• Slightly alkaline
• Contains fetal urine, nutrients, hormones, antibodies, skin cells, & lanugo

Question 2

The average volume of amniotic fluid at birth

Answer 2

800-1000mL

Question 3

(Poly)hydramnios

Answer 3

> 2000mL of amniotic fluid

Question 4

Oligohydramnios

Answer 4

<300mL of amniotic fluid

Question 5

Functions of amniotic fluid

Answer 5

• Maintains even temperature
• Permits embryo to float and develop symmetrically
• Aids in the development of lungs and GI
• Cushions against blows to the abdomen

Question 6

Placenta

Answer 6

• Temporary organ
• Forms around week 3 and grows through week 20

Question 7

Maternal Side of Placenta

Answer 7

• “Raw beefy” appearance
• “Dirty Duncan”

Question 8

Fetal Sid of Placenta

Answer 8

• Shiny appearance
• “Shiny Schultze”
• Umbilical cord attached in center

Question 9

Placenta Funtions

Answer 9

• Gas exchange between mother and fetus
• Nourishment and Excretion
• Hormone Production
• Barrier to nicotine, drugs, alcohol, viruses can cross

Question 10

How does the placenta perform gas exchange

Answer 10

2 arteries carry deoxygenated blood to mother and 1 vein carries oxygenated blood to fetus

Question 11

How does the placenta aid in nourishment and excretion

Answer 11

Delivers nutrients and clears fetus’s metabolic waste products

Question 12

Placenta Hormones

Answer 12

• Influences growth and maintains pregnancy
• HCG, Estrogen, Progesterone, HPL, Relaxin

Question 13

Wharton’s Jelly

Answer 13

Substance surrounding umbilical cord that keeps the vessels separate to keep the cord from kinking

Question 14

Pre-embryonic Stage

Answer 14

Begins with fertilization through implantation

Question 15

What does ectoderm form?

Answer 15

Skin & nervous system

Question 16

What does the endoderm form?

Answer 16

Lining of gut & internal organs

Question 17

What does the mesoderm form?

Answer 17

Muscles, bones, & heart

Question 18

Embryonic Stage

Answer 18

Starts around week 4 through end of week 8; size of a pinhead

Question 19

What forms during embryonic stage?

Answer 19

• Tissue differentiation in all organs
• Week 3: Brain and all 12 cranial nerves present
• Week 4: Heart forms and starts beating

Question 20

What grows during week 5?

Answer 20

• Lung structure
• Liver
• Pancreas
• Kidneys
• GI & sensory organs
• Arm and leg buds appear

Question 21

Week 6

Answer 21

• Hematopoiesis begins (Formation of blood cellular components)
• Baby the size of a pea

Question 22

Week 7 & 8

Answer 22

• Facial features develop
• Renal system begins to function

Question 23

Week 8

Answer 23

• Begins to resemble human being
• Bone cells replacing cartilage
• Fingers & toes developing
• Size of kidney bean

Question 24

Fetal Stage

Answer 24

Weeks 9-40

Question 25

10-12 weeks

Answer 25

- Heartbeat can be heard by doppler

Question 26

Weeks 11-12

Answer 26

Able to make breathing & random movements

Question 27

12 Weeks

Answer 27

- Kidneys producing urine - Digestive system shows activity - Genitals well differentiated - Endocrine organs producing hormones

Question 28

16-20 weeks

Answer 28

- Quickening - Lanugo - Brown fat - Alveoli in lungs forms - Fetus can respond to sound

Question 29

Quickening

Answer 29

Mother feels fetal movement

Question 30

24 weeks

Answer 30

- Grasp & startle reflex evident - Vernix present - Nostrils open - Respiratory movements occur with practice - Alveoli contains some surfactant

Question 31

Surfactant

Answer 31

Slippery substance on alveoli that helps keep them open and lowers surface tension to use less energy to breathe

Question 32

28 Weeks

Answer 32

- Lashes & eyebrows present - Eyelids can open & close - Nervous system beings regulatory functions - Testes descend into scrotum - Looks like little old man

Question 33

32 Weeks

Answer 33

- Respiration & thermoregulation possible if fetus developed - Forming muscles & beginning to store fat - Skeleton fully developed but not calcified to ease delivery - 4-4.5lbs

Question 33

36 weeks

Answer 33

- Diminishing lanugo - Beginning to have "filled out" appearance (more adipose tissue) - Soft ear shells and lobes - Few creases in hands and feet

Question 33

37-40 weeks

Answer 33

- Skin pink and smooth - Vernix in skin folds - Lanugo on shoulders and upper back - Firm ear shells & lobes - Many creases to palms and soles of feet - Well developed labia/scrotum w/ rugae

Question 34

Dizygotic Twins

Answer 34

- 2 ova fertilized by separate sperm (fraternal) - May be same or different sexes - Increases with frequency with increased maternal age & parity, family history (maternal), West African ancestry, and fertility drugs

Question 35

Monozygotic Twins

Answer 35

- 1 ova, 1 sperm; fertilized egg produces 2 fetuses (paternal, identical) - Always same sex (same genes) - Increase with fertility drugs