Pregnancy

Question 1

Dizygotic twinning

Answer 1

two eggs released and fertilized by two different sperm

Question 2

Monozygotic twinning - split 0-4 days

Answer 2

morula
embryo splits during cleavage divisions

two separate amnions and chorions (dichorionic/diamniotic)

Question 3

Monozygotic twinning - split4-8 days

Answer 3

splits at blastocyst stage
two separate amnions but shared chorion
(monochorionic/diamniotic)

Question 4

Monozygotic twinning - split 8-12 days

Answer 4

splits at bilaminar embryonic disc

shared chorion and amnion (monochorionic/monoamniotic)

Question 5

Monozygotic twinning - split >13 days

Answer 5

embryo split incomplete –> conjoined twins

Question 6

Amnion vs chorion

Answer 6

amnion - thin inner membrane

Chorion - thick outer membrane

Question 7

Trophoblast differentiation

Answer 7

Syncytiotrophoblasts

• closest to mom
• produce hCG
• invade endometrium, form lacunae

Cytotrophoblasts

• closest to fetus
• form chorionic villi - O2 nutrient exchange in lacunae

Question 8

Ectopic pregnancy

Answer 8

98% in fallopian tube - ampulla
ovary, abdomen

Risk factors: prior ectopic pregnancy, hx of tubal surgery, hx of PID, smoking, infertility, IUD

Sx:
Classic triad: amenorrhea, vaginal bleeding, abd pain
referred pain to shoulder

Rupture –> severe abdominal pain
urge to defecate - pooling in pouch of douglas

dizziness
lower abdominal tenderness
adnexal mass
rebound tenderness, guarding

Dx: b-hCG (not zero but not normal levels), pelvic ultrasound

Tx: surgery, methotrexate

Question 9

Partial hydatidiform mole

Answer 9

2 sperm + 1 egg –> 69 XXX/XXY/XYY

Fetal parts present
Chorionic villi present
normal uterine size or less than days
elevated hCG

3-5% risk of invasive mole
No risk of cancer

US: grape like clusters; snowstorm appearance of chorionic villi

Tx: D and C, follow hCG to 0

Question 10

Complete hydatidiform mole

Answer 10

1 sperm or 2 sperm + 1 empty egg = 46 XX/XY

No fetal parts
Chorionic villi present
uterine size less than days
significantly elevated hCG

15-20% risk invasive mole
2.5% risk of choriocarcinoma

US: grape like clusters; snowstorm appearance of chorionic villi

Tx: D and C, follow hCG to 0

Question 11

Invasive mole

Answer 11

more common in complete moles
invade locally through uterine wall –> uterine rupture and hemorrhage

Tx: chemo - methotrexate, surgery, follow hCG to 0

Question 12

Choriocarcinoma

Answer 12

metastatic/malignant form
mets to lung!, vagina, brain, liver

50% complete moles, miscarriages, normal pregnancy, ectopic pregnancy, spontaneous

Blood brown vaginal discharge lasting months after delivery

hCG extremely high

Question 13

Urachus

Answer 13

derived from proximal part of allantois
runs between fetal bladder and umbilicus
destined to become umbilical ligament - covered by median fold

if does not involute –> vesicourachal diverticulum, urachal cyst, patent urachus

Question 14

Vitelline duct aka omphalomesenteric duct

Answer 14

connects the yolk sac to the lumen of the midgut - disappears by week 6 of development

remains:
vitelline fistula - meconium from umbilicus
Meckel diverticulum - lower GI bleed

Question 15

Oligohydramnios

Answer 15

placental insufficiency, b/l renal agenesis (Potter sequence), obstruction of urine flow (posterior urethral valves - males)

2nd half of pregnancy, fetal urine most important source of amniotic fluid

Question 16

polyhydramnios

Answer 16

esophageal or duodenal atresia, anencephaly, multiple gestations, uncontrolled maternal DM (glycosuria), congenital infections (parvovirus B19), fetal anemia d/t Rh alloimmunization

Question 17

Elevated AFP

Answer 17

abdominal defects - gastroschisis, omphalocele
neural tufe defects
multiple gestations
incorrect dating

Question 18

Triple/quadruple screen timing and components

Answer 18

15-20 weeks

AFP
Estriol (placenta)
hCG
Quad - inhibin

Question 19

Trisomy 18 vs 21 results of triple/quad screening

Answer 19

18: low AFP, estriol, hCG - everything is low
21: hCG and inhibin high, AFP and estriol low

Question 20

Amniocentesis

Answer 20

fetal cells
-genetic testings - karyotype
neural tube defects

Question 21

Chorionic villus sampling

Answer 21

placental sample

genetic testing
10-13 weeks

Question 22

Physiologic changes in pregnancy

Answer 22

BMR increases 10-20%
plasma volume increases 30-50%, RBC volume increases 20-30% –> physiologic anemia of pregnancy

Cardiac output increases 30-50%
-90% systolic ejection murmur, some S3

BP decreases in early pregnancy –> nadir 24-26 weeks, return to pre-pregnancy by term

Increase GFR –> decreased BUN and Cr

Increased procoagulation factors –> hypercoagulable state
-first few weeks of postpartum as well

Question 23

Placenta previa

Answer 23

placenta overlies cervical os

Risk factors:
increased maternal age
increased multiparity
hx of c-section

Painless vaginal bleeding late in pregnancy

dx: US BEFORE digital exam

Tx: c-section

Question 24

Placenta accreta vs placenta increta vs placenta percreta

Answer 24

Accreta: placenta adherence to myometrium

Increta: invasion into myometrium

Percreta: penetrate through uterus –> bowel and bladder

All associated w/ placenta previa and prior c-sections

Dx: US

Tx: c-section - risk life threatening hemorrhage
Hysterectomy

Question 25

Placental abruption (abruptio placentae)

Answer 25

premature separation of placenta
hematoma between uterus and placenta

can lead to DIC

Risk factors:
hx of prior placental abruption
htn
trauma
smoking
*cocaine use*

Sudden onset painful vaginal bleeding –> fast labor
contractions
fetal distress on HR monitor

Tx: emergency C section

Question 26

Uterine atony

Answer 26

enlarged soft, boggy uterus

Risk factors: overdistended uterus - large fetus, multifetal gestation, induced or augmented labor, prolonged labor
“over worked”

Most common cause of postpartum hemorrhage

dont get myometrial contraction to close spiral a., stay open –> bleeding

Question 27

Causes of postpartum hemorrhage

Answer 27

Uterine atony
Retained placental tissue - prevents myometrium from contracting down

genital lacerations
abnormal placentation - placenta accreta/increta/percreta
uterine rupture - rare but serious
coagulation defects

Question 28

Chronic hypertension in pregnancy

Answer 28

HTN before pregnancy
ACEI teratogen

Meds in pregnancy:
Methyl DOPA - central a2 receptor agonist
Labetalol - alpha/beta blocker

Question 29

Gestational HTN

Answer 29

arises during pregnancy, resolves postpartum

new onset >140/90 after 20 weeks

no proteinemia

monitor for progression

Question 30

Pre-eclampsia

Answer 30

gestation htn + proteinuria OR end organ dysfunction

widespread endothelial vessel dysfunction –> leaky

Risk:
hx of preeclampsia
extremes of age
nulliparity
chronic HTN
DM
multifetal gestations
hydatidiform moles

Dx: >140/90 after 20 wks
Proteinuria >= 300 mg/24 hours
If no proteinuria: thormobcytopenia, renal insuffiency, elevated LFTs, pulmonary edema, cerebral or visual sx

Question 31

Severe pre-eclampsia

Answer 31

end organ dysfunction

BP >160/110

Question 32

HELLP Syndrome

Answer 32

Hemolysis
Elevated Liver enzymes
Low Platelets

Question 33

Eclampsia

Answer 33

seizure

tx; MgSO4

Question 34

Treatment of severe preeclampsia, HELLP sn, eclampsia

Answer 34

Rapid acting anti-htn - hydralazine, labetalol, nifedipine to prevent stroke or placental abruption

MgSO4 to prevent seizure

Delivery

Question 35

Human placental lactogen (HPL)

Answer 35

produced by placenta
decreased insulin sensitivity in mom so more glucose available to fetus

exaggerated response –> gestational DM

Question 36

Gestational diabetes

Answer 36

develops during pregnancy, resolves postpartum

screen w/ OGTT between 24-28 weeks gestation

Manage: diet +/- insulin

Complications:
macrosomia
hypoglycemia after delivery: high glucose state in utero –> beta cells hyperplasia in pancreas –> increased insulin –> hypoglycemia

Question 37

Pregestational diabetes

Answer 37

Overt DM prior to pregnancy

Insulin mgmt

Complications:
macrosomia
hypoglycemia
congenital anomalies: cardiac defects, caudal regression syndrome (sacral dysgenesis - lower body doesn’t form properly), still birth, deliver earlier

Question 38

Terbutaline

Answer 38

asthma and tocolytic

selective B2 agonist –> uterine relaxation

SE: tachycardia, hypotension, pulmonary edema

Question 39

Ritodrine

Answer 39

preterm labor

not used in US

Question 40

Prostaglandin drugs

Answer 40

Cause cervical dilation and uterine contraction
early –> termination
Late –> induce

Dinoprostone - PGE2
Misoprostol PGE1

Question 41

Misoprostol

Answer 41

PGE1
also used in PUD, keep PDA open

SE: excessive uterine stimulation –> fetal distress, uterine rupture

Question 42

Mifepristone (RU486)

Answer 42

competitive antagonist at progesterone receptor
antiprogesterone

Early –> blastocyst detach, myometrium contract –> termination

Give w/ misoprostol

SE: vaginal bleeding, abdominal pain/cramping, N/V/D