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Flashcards in Preterm Labor Deck (55):
1

Define parturition.

the action of giving birth

2

What is preterm, generally?

Birth less than 37

3

What is late preterm?

[34-37)

4

What is early preterm?

Less than 34

5

What is the definition of term?

[37 - 42)

6

What is early term?

[37 - 39)

7

What is full term?

[39 - 42)

8

What is post term?

Greater than 42

9

What is the leading cause of neonatal death?

Preterm

10

What is the definition of SGA? LGA?

SGA = Less than the 10th percentile

LGA = Greater than the 90th percentile

11

What is the definition of low birthweight?

Less than 2500 g

12

What is the definition of very low birthweight?

Less than 1500g

13

What is the definition of extremely low birthweight?

Less than 1000g

14

True or false: SGA = preterm

False--related but not equivalents

15

True or false: once infants survive prematurity, they have the same survival rate

False--lower

16

What are the two major adverse pulmonary events associated with prematurity? (2)

-NRDS
-Bronchopulmonary dysplasia

17

What are the CV adverse effects of prematurity? (3)

PDA
Apnea/bradycardia
Hypotension

18

What are the major adverse GI effects of prematurity? (3)

-Necrotizing enterocolitis
-Jaundice
-Dysmotility
-Hypoglycemia

19

What are the major adverse ophthalmological effects of prematurity? Why?

Retinopathy of prematurity d/t the need to ventilation and O2

20

What (potentially) is the long term risk factor for neonatal hypoglycemic episodes?

Developmental delays

21

What is the pathophysiology behind the retinopathy of prematurity?

Giving Oxygen to premies encourages growth of blood vessels in the retina (which would have been fully formed if born at term). This causes proliferation, and regression once oxygen is stopped, leading the vessels to die. Death of vessels is a inciting factor for retinal detachment

22

What histological changes occur within the uterus that allows for contractions?

Increased connectivity d/t increase in Connexins, and gap junctions

23

What is the hormone that sets off uterine contractions?

CRH

24

How useful is a single measurement of CRH in determining the timing of the "fetal clock"?

Not very--need multiple to define a function

25

True or false: CRH levels, and thus the fetal clock, appear to be set at the level of implantation

True

26

What are the A and B isoforms of progesterone receptors? What happens to the ratio of these when labor occurs?

A = Contraction
B = quiescent

A becomes more predominant as labor approaches

27

True or false: only a small fraction of preterm labor is recurrent

True

28

True or false: a mother who was preterm is more likely to have a preterm child

True

29

The risk of preterm labor is (__)x for african americans than for white

2x

30

Is prior stillbirth a risk factor for spontaneous preterm birth

Yes

31

Any women with abdominal or pelvic pain after how many weeks gestation should be suspected of preterm labor?

16 weeks

32

What is the strongest predictor of having a preterm birth?

Having had a preterm birth before

33

How often is preterm labor accurately diagnosed?

50%

34

What are the early s/sx of premature labor?

Menstrual-like cramps
Back pain
Vaginal d/x

35

What dilation size indicates labor?

3 cm

36

What percent of cervical effacement indicates labor?

75-80%

37

What is the cornerstone of the diagnosis of preterm labor?

Cervical thickness

38

What defines a shortened cervix?

Less than 3 cm

39

What is the length of the cervix that indicates imminent (days to a week) delivery?

Less than 1 cm

40

What is fetal fibronectin (fFN), and what role does it play in pregnancy?

Glycoprotein component of the ECM, that may be involved in the adhesion of fetal membranes to decidua.

Declines after 24 weeks

41

How do you obtain fFN? Why?

Swab BEFORE doing a pelvic exam or using a speculum, o/w cannot obtain for 24 hours

42

What is the utility of measuring fetal fibronectin (fFN)?

If negative, unlikely that the women will deliver in the next few weeks.

If positive, then not useful

43

What are the two measurements that aid in identifying when labor is imminent?

US + fFN

44

What is the cervical length that indicates that it is safe to d/c the patient? What indicates that the patient will probably go into labor?

More than 30 mm

Less than 20 mm

45

If a pt is between 20-29 mm in cervical length, and has a positive fFN, what should be done? What about a negative?

Positive = will go into labor

Negative = consider observation

46

What is the effect of nifedipine on uterine contractions?

BLocks Ca channels to block contractions

47

What is the medication of choice that inhibits prostaglandin action on myometrial cells to inhibit contraction?

Indomethacin

48

What is the MOA of terbutaline in the uterus?

Inhibits beta receptors on the uterus to inhibit contractions

49

Using terbutaline in twin pregnancies results in what?

Pulmonary edema

50

What is the MOA of prostaglandins to stimulate uterine contractions?

Increases Ca levels, and gap junction formations

51

What is the MOA of MgSO4 in prevent uterine contractions?

decreases Ca influx

52

Giving Mg prior to delivery does what for a preterm baby?

Protects the blood vessels within the developing brain

53

Is bed rest indicated for pregnant women?

No--increases muscle atrophy and risk for VTE

54

What can't you use indomethacin as a tocolytic after 34 weeks?

Risk closing the ductus arteriosus

55

How long can indomethacin maintain a pregnancy?

48 hours