Obstetrics

Question 1

Relative hemodilution of pregnancy

Answer 1

Blood volume increases 36% by 34 weeks. The plasma volume increases 47% and the RBC mass increases only 17%. This relative dilutional effect lowers the hemoglobin, but causes no change in the MCV.

Question 2

Physiologic dyspnea of pregnancy

Answer 2

75% of woman by third trimester. Ok if Hgb 10 and if 2/6 systolic murmur.

Question 3

Acid base status of pregnancy (even if URI)

Answer 3

Increased minute ventilation -> respiratory alkalosis -> metabolic acidosis (decreased bicarb) compensation

Question 4

PFT in pregnancy

Answer 4

Increased minute ventilation, tidal volume, and inspiratory capacity. Decreased FRC, ERC, and RV. No change in RR.

Question 5

Pulmonary edema in pregnancy

Answer 5

*Decreased plasma osmolality, **tocolytic use, fluid overload, preeclampsia, chorioamnionitis (if septic)

Question 6

CO in pregnancy

Answer 6

Increases 33% d/t increased HR and SV. SVR decreases (but always greater than PulmVR unless R>L shunt)

Question 7

R hydronephrosis in pregnancy

Answer 7

R>L because sigmoid colon cushions L ureter; and because of dextrorotation of uterus causing more obstruction of R ureter; R ovarian vein complex dilates during pregnancy; high progesterone levels

Question 8

Thyroid changes in pregnancy

Answer 8

Estrogen -> increased TBG -> no change in free T3 or T4

Question 9

Molar pregnancy (gestational trophoblastic disease) workup

Answer 9

CXR, bc lungs most common mets; weekly beta-hCG

Question 10

Recommended weight gain in pregnancy

Answer 10

BMI 30: gain 11-20 punds

Question 11

SCD trait

Answer 11

1/10 AA are carriers

Question 12

African American couple, workup in pregnancy

Answer 12

Hgb electrophoresis and CBC (SCD, alpha and beta thalassemia)

Question 13

Ashkenazi jew screening

Answer 13

Tay-Sachs, Fanconi anemia, CF, NPD

*CFNT

Question 14

Beta thalassemia -population

Answer 14

Mediterraneans

Question 15

VPA birth defects

Answer 15

neural tube defects (lumbar meningomyelocele), hydrocephalus and craniofacial malformations, cardiac, hypospadias, limb (radial aplasia)

Question 16

T1DM poorly controlled prior to pregnancy - greatest risk birth deffect

Answer 16

Cardiac and neural tube defects, as well as limb and GU; IUGR; caudal regression syndrome; SGA (not macrosomia); hypoglycemia

Question 17

CVS

Answer 17

• 10-12 weeks GA

- fetal chromosomal abnormalities, biochemical, or DNA-based studies

Question 18

Best testing for Down’s

Answer 18

• Sequential screen: (first trimester NT and PAPP-A + second trimester quad screen) 93% Detection Rate
• Quad: AFP, B-hCG, Estradiol uE3, Inhibin A

Question 19

Dating when LMP and positive test and uterus size are different

Answer 19

US between 14 and 20 weeks if there is greater than a 10 day discrepancy from the menstrual dates

Question 20

Trimester weeks

Answer 20

1: 0-12
2: 13-27
3: 28-40

Question 21

GDM screening

Answer 21

24-28 weeks
50g OCT: ≥140 at 1 hr positive
100g OTT: two of three of fasting >95, 1 hour ≥180, 2 hour ≥155, or 3 hour ≥140

Question 22

GDM risks

Answer 22

Polyhydramnios, macrosomia, hypoglycemia, hypocalcemia, preeclampsia, polycythemia, hyperbilirubinemia, respiratory distress

Question 23

35yo woman with negative 1st trimester screen but elevated NT and self-concern for Down’s. Next noninvasive test?

Answer 23

Detailed fetal ultrasound and echocardiogram at 18-20 weeks to rule out anomalies.

Question 24

Ibuprofen in pregnancy

Answer 24

Safe until 32 weeks, when premature closure of the ductus arteriosis is risk

Question 25

Signs of labor

Answer 25

Contractions every five minutes for one hour, rupture of membranes, fetal movement less than 10 per two hours or vaginal bleeding

Question 26

Woman in labor. Cannot get fetal HR because woman cannot sit still. What do you do?

Answer 26

Fetal scalp electrode. Do NOT place epidural without confirming FHR.

Question 27

Baby crowning, but FHR in 60s. What do you do?

Answer 27

Operative-assisted vaginal delivery (vacuum/forceps) if cannot deliver withhin 1-2 pushes

Question 28

Labor and ROM. Cervix staying at 5 cm, so you placed IUPC. On placement, 300 cc of frank blood and amniotic fluid flow out. Next step?

Answer 28

Consider placenta separation or uterine perforation. Withdrawing cath, monitor fetus. If reassuring, then another attempt at cath.

Question 29

Early decelerations

Answer 29

Vasovagal head compression

Question 30

Late decelerations (onset, nadir, and recovery of the decelerations occur, respectively, after the beginning, peak and end of the contraction)

Answer 30

Uteroplacental insufficiency

Question 31

Variable decelerations (most common)

Answer 31

Cord compression - oligohydramnios?

Question 32

Sustained bradycardia

Answer 32

Cord prolapse

Question 33

5cm segment of cord prolapsed into vagina while fetus at 1+ station, FHR reassuring.

Answer 33

Elevate the fetal head with a hand in the patient’s vagina and call for assistance to perform a Cesarean delivery

Question 34

Woman in labor with ROM 2 days ago and fever (chorioamnionitis), FHR 180 with minimal variability (septic). What will baby look like?

Answer 34

Lethargic, pale, fever

Question 35

TTTS in monochorionic twins

Answer 35

Donor twin: Anemia, IUGR and oligohydramnios

Recipient twin: Polycythemia, volume overload and polyhydramnios -> heart failure and hydrops

Question 36

Infant born with narcs in system, limp, unresponsive, no respiratory effort. Treatment?

Answer 36

Positive pressure ventilation and prepare to intubate. No naloxone if possible substance abuse in mother d/t life-threatening withdrawal.

Question 37

Infant born Cesarean to HIV mother

Answer 37

Antiretrovirals during pregnancy. AZT (zidovudine) to infant immediately after birth, and HIV testing starting at 24 hours. No breast feeding.

Question 38

Risk factors for postpartum endometriitis

Answer 38

Mode of delivery: Cesarean, prolonged labor, prolonged ROM, multiple vag exams, internal fetal monitoring, manual placental removal, low socioeconomic status

Question 39

Cardinal movements of labor

Answer 39

• Engagement
• Descent
• Flexion
• Internal rotation
• Extension
• External rotation

Question 40

Most common cause of postpartum fever

Answer 40

Endometritis (even mild uterine fundal tenderness)

- Polymicrobial, both anaerobic and aerobic (most common staph and strep)

Question 41

PPD v. PP blues

Answer 41

PPD > 2 weeks, ambivalence toward newborn

Question 42

PPD risk factors

Answer 42

Personal hx of depression > marital conflict, lack of perceived social support from family and friends, having contemplated terminating the current pregnancy, stressful life events in the previous twelve months, and a sick leave in the past twelve months related to hyperemesis, uterine irritability or psychiatric disorder

Question 43

Best way to stop lactation

Answer 43

breast binding, ice packs and analgesics

Question 44

Benefits of breastfeeding

Answer 44

• Increased uterine contraction and decreased blood loss due to oxytocin release
• Decreased incidence of ovarian cancer (and breast cancer?)

Question 45

Breast milk synthesis

Answer 45

Progesterone, estrogen, placental lactogen, prolactin, cortisol, and insulin act in concert to stimulate the growth and development of the milk-secreting apparatus of the mammary gland.

• Prolactin: synthesis of milk, but action inhibited by estrogen and progesterone. After delivery, inhibitory action of estrogen and progesterone is lifted
• Suckling -> oxytocin increase -> let down

Question 46

Treatment of breast engorgement (common when milk comes in)

Answer 46

• Frequent nursing, warm shower/compress, massaging, bra, analgesic