Obstetrics - Normal Pregnancy + Prenatal care

Question 1

Embryo vs fetus

Answer 1

< 8 weeks = embryo

> 8 weeks = fetus

Question 2

1st vs 2nd vs 3rd trimester

Answer 2

1st - 0-12 wks

2nd - 12-28 wks

3rd - 28 - delivery

< 24 weeks - previable

24-37 weeks - preterm

> 37 weeks - term

Question 3

Signs of pregnancy

Answer 3

Bluish discoloration of vagina and cervix (Chadwick sign)
Softening and cyanosis of the cervix at or after 4 wk (Goodell sign)
Softening of the uterus after 6 wk (Ladin sign)

Question 4

Physio of pregnancy - CV

Answer 4

cardiac output increases by 30% to 50%.
- The increase in cardiac output is first due to an increase in stroke volume and is then maintained by an increase in heart rate as the stroke volume decreases by the end of the third trimester.

Systemic vascular resistance decreases —> decrease BP
- most likely 2/2 elevated progesterone, leading to smooth muscle relaxation.

Question 5

Physio of pregnancy - Pulm

Answer 5

The increased minute ventilation during pregnancy causes a compensated respiratory alkalosis.

Will have dyspnea

Increase:
Tidal volume
Minute ventilation (b/c inc tidal volume but RR stays same)
INspiratory capacity

Decrease:
TLC (2/2 elevation of diaphragm)
Functional residual capacity

Constant:
RR

Plasma osmolality is decreased during pregnancy which increases the susceptibility to pulmonary edema. - Common causes of acute pulmonary edema in pregnancy include tocolytic use, cardiac disease, fluid overload and preeclampsia.

Question 6

Physio of pregnancy - Heme

Answer 6

Increase:
Plasma volume
RBC volume (less than plasma volume)
Coagulability

Decrease:
Hct (plasma volume&raquo_space; RBC vol) —-> dilutional anemia

Question 7

Physio of pregnancy - Endo

Answer 7

Increase:
TBG (stimulated by estrogen) —->
TOTAL T3, T4

Same:
Free T3, T4

Question 8

Physio of pregnancy - MS

Answer 8

spider angiomata

palmar erythema secondary to increased estrogen levels

hyperpigmentation of the nipples, umbilicus, abdominal midline (the linea nigra), perineum, and face
(melasma or chloasma) secondary to increased levels of the melanocyte-stimulating hormones and the steroid hormones.

Carpal tunnel syndrome

Question 9

Prenatal visits

- what is done?

Answer 9

Blood pressure, weight, urine dipstick, measurement of the uterus, and auscultation of the FH are performed and assessed on each follow-up prenatal care visit.

Question 10

The FH is usually first heard during the

Answer 10

second trimester, as is the first fetal movement

Question 11

patients who are Rh negative should receive Rho-GAM at _____ weeks.

Answer 11

28

Question 12

Prenatal visit increments

Answer 12

Prenatal visits increase to every 2 to 3 weeks from 28 to 36 weeks and then to every week after 36 weeks.

Beyond 32 to 34 weeks, Leopold maneuvers are performed to determine fetal presentation

Question 13

In women with latent herpes simplex virus (HSV), antiviral prophylaxis can be initiated at ____ weeks.

Answer 13

36

Active HSV would be an indication for cesarean delivery.

Question 14

Occasional irregular contractions that do not lead to cervical change are considered

Answer 14

Braxton Hicks contractions

Question 15

dehydration in preggers can lead to

Answer 15

uterine contractions, possibly secondary to cross-reaction of vasopressin with oxytocin receptors

Question 16

BPP looks at five categories and gives a score of either 0 or 2 for each:

Answer 16

amniotic fluid volume, 
fetal tone,
fetal activity, 
fetal breathing movements, 
the nonstress test (NST), which is a test of the FHR. 

A BPP of 8 to 10 or better is reassuring.

Question 17

Blood flow in the middle cerebral artery is used when evaluating for

Answer 17

fetal anemia in the setting of Rh isoimmunization

Question 18

On fetal monitoring, late FHR decelerations are concerning for

Answer 18

uteroplacental insufficiency

Question 19

At ____ weeks, screening for group B streptococcal

infection is also performed.

Answer 19

35-37 weeks

Patients who have a positive culture should be treated with intravenous penicillin when they present in labor to prevent potential neonatal group B streptococcal infection

Question 20

Gestational diabetes - risks

Answer 20

Intrauterine growth restriction is typically seen in women with pre-existing diabetes and not with gestational diabetes.

Shoulder dystocia, metabolic disturbances, preeclampsia, polyhydramnios and fetal macrosomia are all associated risks of gestational diabetes

Question 21

Accurate GA dating is made by

Answer 21

Certain LMP c/w first or second trimester US

dating by 3rd trimester US or unsure LMP is more suspect

Question 22

How do you get a di-di pregnacy?

Answer 22

Separation of ovum prior to differentiation of trophoblast

will get 2 amnions and 2 chorions

Question 23

How do you get mono-di pregnancy?

Answer 23

Separation of ovum after trophoblast differentiation adn before amnion formation

will get 1 chorion adn 2 amnions

Question 24

How do you get mono-mono pregnancy?

Answer 24

Separation of ovum after trophoblast differentiation and after amnion formation

1 chorion
1 amnion

Question 25

Division of cells beyond what day will give you singleton fetus?

Answer 25

15-16 days

Question 26

GBS screening Tx

Answer 26

35-37 weeks Cx of vagina and rectum Tx w/ IV penicillin G at time of labor or ROM - If status unknown and labor prior to 37 wks GA or ROM > 18 hrs --> tx with PXN G - also can use cefazolin (ancef) if PCN allergic - Vanco for GBS resistant to clinda or unknown susceptibility

Question 27

Screen for gonorrhea

Answer 27

1st prenatal visit and 3rd trimester

Question 28

Screening for syphilis

Answer 28

VDRL or RPR If + - send titer - confirm with FTA-Abs to r/o false + (SLE, antiphosphlipid ab syndrome)

Question 29

Morning sickness resolves by week

Answer 29

16

Question 30

Patients who desire non-invasive assessment of their risk for aneuploidy can have

Answer 30

first trimester screen (a fetal nuchal translucency (NT) measurement and a maternal serum PAPP-A) - if +, can have detailed fetal US and echo at 19-20 weeks to r/p anomalies if doesn't want an amnio or CVS a second trimester quadruple screen.

Question 31

Ibuprofen is safe to take until around

Answer 31

32 weeks gestation, when premature closure of the ductus arteriosis is a risk

Question 32

Progesterone in pregnancy

Answer 32

>25 ng/ml suggests healthy pregnancy

Question 33

bHCG levels in pregnancy

Answer 33

Should rise by at least 50% every 48 hours until the pregnancy is 42 days old after that time, the rise in level may not follow the curve

Question 34

Nonstress test

Answer 34

assessment of fetal well-being that measures the fetal heart rate response to fetal movement. nl = two fetal heart rate accelerations of 15 beats/minute for 15 seconds within 20 minutes. Vibroacoustic stimulation is not indicated unless the NST is non-reactive.

Question 35

Contraction stress test

Answer 35

assesses uteroplacental insufficiency and looks for persistent late decelerations after contractions (3/10 minutes)

Question 36

Methods to date a pregnancy - best methods | 1st trimester

Answer 36

1st trimester | - US measurement of crown-rump length is best

Question 37

Chorionic villus sampling vs amniocentesis

Answer 37

Chorionic villus sampling (CVS) - performed between 10 and 12 weeks gestation - use FISH to analyze cells - increased risk fetal death and limb reduction defects - limb reduction defects occurs when procedure carried out before 9-10 wks GA Amniocentesis - performed after 15 weeks

Question 38

Gold standard to eval cervix for incompetence in pregnancy

Answer 38

Transvaginal US length < 10th % for GA is short cervix

Question 39

Exercise contraindicated in pregnancies with...

Answer 39

``` Amniotic fluid leak Cervical incompetence Mult gestation Placenta abruption Placenta previa Premature labor Preeclampsia Gestational HTN Severe heart or lung dz ```

Question 40

Nl amniotic fluid pH

Answer 40

neutral 7-7.5

Question 41

Cause of low back pain in third trimester pregnancy

Answer 41

Increase in lumbar lordosis Relaxation of ligaments supporting joints of pelvic girdle