LEC49: Late Fetal Period & Twins Flashcards Preview

Structures: Part Deux > LEC49: Late Fetal Period & Twins > Flashcards

Flashcards in LEC49: Late Fetal Period & Twins Deck (66):
1

fragment of time OBGYNs measure trimesters by

weeks, not months

2

1st trimester time pd

weeks 1-13

3

2nd trimester time pd

weeks 14-27

4

3rd trimester time pd

weeks 28-40

5

what occurs during 1st trimester

major organ systems form

6

what occurs during 2nd trimester

fetal growth, differentiation- organ systems develop ability to take on roles, fxns as they should in a born baby

7

ultrasound fxn

allows to visualize fetus, see anomalies

8

when is fetus viable

24 weeks from LMP, end of 2nd trimester

9

when is fetus peri-viable?

23 weeks
may survive

10

what occurs during 3rd trimester

continued growth, maturation, development of embryo

11

why is it important to accurate date pregnancy?

many things occur at very specific times during pregnancy so must know accurately how old fetus is

12

when can visualize fetal heart beat on U/S?

6 weeks from LMP, 4 weeks since conception

13

what are carnegie stages?

why to visualize embryonic pd of fetal development - til 8 weeks, 10 weeks from LMP
visualize by morpholgy, not just by age

14

CRL

crown-rump length: measure from crown of head to rump- accurate for dating fetus within 3-5 days

15

when can use CRL?

7-13 weeks

16

weeks 9-12 features

1) head = 1/2 CRL of fetus
2) eyes fused
3) ears low
4) see some ossification cts appear in skeleton

17

when do primary ossification cts appear?

end of 12th week

18

weeks 13-16 highlights

1) coordinated limb movements
2) ossification of skeleton active
3) scalp hair patterning determined
4) genetalia recognizable
5) eyes anterior

19

17-20 week highlights

1) mother feels movement
2) skin covered w/ vernix
3) fine lanugo hair present
4) brown fat forms- heat production
5) anatomy US routinely performed

20

what is vernix

waxy white protection over skin
appears weeks 17-20

21

why might baby at 24 weeks have trouble w/ heat production

brown fat hasn't formed

22

when is uterus at level of umbilicus/bellybutton?

20 weeks since LMP
1 cm from pubic symphysis=1 week

23

21-24 weeks features

1) skin wrinkled, translucent
2) beginning of surfactant production
3) viability est

24

26-29 weeks features

1) lungs more developed
2) CNS can control rhythmic breathing, body temp
3) eyelids open at 26 weeks
4) subcutaneous fat

25

30-34 weeks features

1) skin pink, smooth
2) 32 weeks decreased risk of bleed in brain
3) majority survive

26

when do eyelids open

26 weeks

27

when is preterm

< 27 weeks

28

when is early term

37-38+6 weeks

29

when is full term

39-40+6 weeks

30

when is post term

42+ weeks

31

biggest risk factor for having a preterm birth?

if mom has prior hx of having preterm birth

32

all risk factors for preterm birth?

1) prior preterm birth
2) uterine anomaly
3) multiple gestation
4) excess amniotic fluid
5) cigarettes/drug use
6) intrauterine infection

33

how to treat woman who has had prior preterm birth?

progesterone-like injections

34

diabetes effect on fetal growth?

if mom has diabetes, excess sugar stimulates fetus to create growth factor; can get fetus that's TOO BIG or too SMALL

35

what factors might restrict fetal growth?

1) vascular disease
2) hypertension
3) cigarettes
4) genetic disorders
5) anti-phospholipid antibody syndrome

36

possible post-term issues?

1) increase in mortality
2) dry parchment-like skin, long nails, decreased vernix
3) meconium aspiration

37

spontaneous incidence of multiple gestations in US?

twins: 1/80
triplets: 1/8,000

38

why increase in multiple births nationwide?

use of ART, increase in maternal age

39

what are dizygotic twins

twins from 2 diff eggs; each forms own amnion, chorion

40

which type of twinning is familiar

dizygotic

41

percentage of twins that're dizygotic

2/3 twins

42

is dizogytic twins maternal or paternal inheritance

maternal

43

what is monozygotic twins

1 embryo that splits
if 4-8 day split, 1 placenta w/ 2 sacs
if 8-13 day split, 1 sac - risk for fetal death

44

when do conjoined twins occur

after day 13, monozygotic twins

45

is monozygotic twins inherited

no

46

which has better outcome- dizogytic or or monozogytic twins

dizogytic twins

47

hw might monozygotic twins present

2 separate amnions; 1 placenta w/ 2 diff sacs OR if split before day 4, 2 placentas w/ 2 sacs

48

day 3-5 twin type

di/di

49

day 5-8 twin type

mc/di

50

day 8-13 twin type

mc/ma

51

day 13+ twin type

conjoined twins

52

what are monochorionic twins risk for?

1) fetal growth restriction
2) twin-twin transfusion syndrome
3) congenital anomalies
4) miscarriage
5) preterm birth

53

degree of risk, least to greatest, re: twin type?

dizygotic
di and mono
mono mono

54

complications of multiple births for baby?

1) preterm brith
2) low birth weight
3) neonatal morbidity and morality
4) congenital anomalies
5) chromosomal abnormalities
6) spontaneous fetal loss

55

complications of multiple births for mom?

1) gestational diabetes
2) preeclampsia
3) cesarean delivery
4) maternal hemorrhage
5) acute fatty liver
6) placenta previa

56

when did rate of twins peak in USA

1998

57

when do singletons deliver

39-40 weeks

58

when do twins deliver

35-36 weeks

59

when do triplets deliver

33 weeks

60

when do quads deliver

30 weeks

61

what delivers earlier- multiple births or singleton?

multiple births

62

complications of prematurity

1) hypothermia
2) patent ductus arteriosus
3) intracranial hemorrhage
4) hypoglycemia
5) respiratory abnormalities
6) necrotizing enterocolitis
7) infection
8) retinopathy of prematurity
9) learning disabilities, developmental delays, cerebral palsy

63

risk of CP in multiple birth?

twins: 5x increased risk
triplets: 17x increased risk

64

what factors increase perinatal morbidity, mortality?

fetal growth restriction and discordant growth

65

why do dizygotic twins have great risk of chromosomal anomalies?

each twin has independent risk, whereas monozygotic twins have genetically identical risk
so 2x age related risk for dz twins

66

what about ART might increase risk of chromosomal abnormalities?

sperm from subfertile men/women may increase risk of chromosomal and gene abnormalities w/ ART