Fetus & Placenta

Question 1

gestational length of pregnancy

Answer 1

40 weeks from onset of LMP

Question 2

fertilization length of pregnancy

Answer 2

38 weeks from fertilization (woman is already 2 weeks pregnant at first missed period)

Question 3

what week does fetal period begin?

Answer 3

9 weeks

Question 4

When do most malformations occur?

Answer 4

during embryonic period

Question 5

first trimester key points

Answer 5

ossification centers have formed, eyelids fused, fetus active but not big enough to feel, external sexual differentiation, herniated intestinal loop returns to abdominal cavity

Question 6

second trimester key points

Answer 6

fetus practices sucking and other reflexes, swallowing, urinating, breathing, hair on head and face, lanugo hair around body, surfactant in lungs, vernix caseosa around skin, meconium in large intestine

Question 7

polyhydramnios

Answer 7

too much fluid, swallowing impaired

Question 8

oligohydramnios

Answer 8

too little fluid, urination impaired

Question 9

results of oligohydramnions

Answer 9

Potter’s syndrome; clubbed feet, pulmonary hypoplasia, cranial anomalies

Question 10

vernix caseosa

Answer 10

sebaceous gland secretions mixed with sloughed epidermal cells; lubricate skin

Question 11

meconium staining

Answer 11

green/yellow amniotic fluid at birth; indicator that baby was stressed in utero

Question 12

third trimester key points

Answer 12

all second trimester features, most of fat and weight added, more surfactant in lungs

Question 13

amniocentesis for lung maturity

Answer 13

can be used to measure amount of surfactant

Question 14

chorion frondosum

Answer 14

part of chorion with villi

Question 15

chorion laeve

Answer 15

part of chorion without villi

Question 16

fetal exchange villus

Answer 16

losses cytotrophoblast and connective tissue to allow for more rapid exchange

Question 17

embryonic exchange vills

Answer 17

syncytium, cytotrophoblast, endothelium, connective tissue

Question 18

decidua

Answer 18

renamed endometrium

Question 19

decidua capsularis

Answer 19

portion underlying chorion laeve

Question 20

decidua basalis

Answer 20

where moms blood is going to be circulating into the placenta

Question 21

decidua parietalis

Answer 21

everything else associating with uterine wall

Question 22

chorion

Answer 22

completely embedded in the endometrium at this point

Question 23

What membranes breaks when water breaks?

Answer 23

chorion laeve and amnion

Question 24

cotyledons

Answer 24

groups of villi

Question 25

umbilical cord

Answer 25

amnion on surface and vessels associated with it; intestinal loop, allantois, vessels

Question 26

umbilical vein

Answer 26

supplies oxygen from placenta to fetus

Question 27

umbilical arteries (2)

Answer 27

return deoxygenated blood from fetal internal iliac arteries to placenta

Question 28

Where do umbilical arteries and veins derive from?

Answer 28

allantois

Question 29

first stage of parturition (labor & delivery)

Answer 29

dilation of the cervix from uterus contraction, water breaking

Question 30

second stage of parturition

Answer 30

delivery of fetus

Question 31

third stage of parturition

Answer 31

delivery of placenta and membranes

Question 32

dizygotic

Answer 32

fraternal

Question 33

fraternal twins

Answer 33

a. dichorionic, diamnionic with own placenta

b. dichorionic, diamnionic with shared placenta

Question 34

monozygotic

Answer 34

identical

Question 35

identical twins

Answer 35

a. splitting at 2 cell stage; own placenta, diamnionic, dichorionic
b. splitting at early blastocyst; common placenta and chorion, separate amnions
c. splitting at later blastocyst; sharing everything, most dangerous

Question 36

most identical twins are _

Answer 36

monochorionic, diamnionic

Question 37

transfusion syndrome

Answer 37

one twin gets more blood than the other; much larger

Question 38

drugs between 0-2 weeks

Answer 38

fatal

Question 39

drugs between 3-8 weeks

Answer 39

will result in malformations, embryo is very sensitive to insult

Question 40

drugs between 9-38 weeks

Answer 40

embryo less sensitive; usually just problems with organ growth or function

Question 41

chorionic villus

Answer 41

can be done before amniocentesis is an option or if too little amnionic fluid