OBSTETRICS Flashcards
Changes in thyroid hormone observed during pregnancy
Since TBG increases, total T4 will increase but free T4 remains unchanged. TSH will also decrease slightly during early pregnancy but remains within normal limits.
Why is metabolic alkalosis seen during pregnancy?
PCO2 decreases to about 30 mm Hg which makes sense because mom wants to release more oxygen to baby.
Tidal volume changes in pregnancy
Tidal volume increases 40% with associated increase in minute ventilation due to stimulation by progesterone.
Glucose-related changes during pregnancy
Non-diabetic hyperinsulinemia with associated mild glucose intolerance.
Production of human placental lactogen contributes to glucose intolerance by interfering with insulin activity
Treatment of GERD during pregnancy
CAlcium carbonate. H2 blockers and PPIs are also safe. The only thing that is NOT safe is milk of magnesia (recall magnesium induces tocolytic effects)
At what gestational age is physiologic anemia of pregnancy most apparent?
Second trimester due to greater increase in plasma volume as compared to BC mass.
When should anemia in pregnancy be treated with oral iron?
If Hb falls below 11 in first or third trimesters OR when less than 10.5 in second trimester.
What is Goodell’s sign?
Softening and cyanosis of cervix at 6 weeks gestation
What is Chadwicks sign
Bluish discoloration of the vagina due to vascular congestion at 8-12 weeks gestation
What is Hegars sign
Softening of the uterus at 6 weeks gestation
Folic acid requirement in all women of childbearing years
.4 mg daily
IF previous child wit neural tube defect, recommended folic acid intake?
Starting the mont prior to pregnancy, 4 mg daily.
When do you do Group B strep screening?
36 weeks gestation. Thats because its only good for 4 weeks.
Increased nuchal translucency
Down syndrome
Turner syndrome
Congenital heart defects
MCC of abnormal quad screen
Incorrect dating
Serum AFP is only valid if performed during what window
16-18 weeks gestation
High aFP
Increased risk of neural tube defects or multiple gestations
Low aFP
Increased risk of trisomies 21 and 18
Low PAPP-A
Elevated hCG
Elevated nuchal traslucency
Trisomy 21
Very low PAPP-A, very low hCG, increased nuchal translucency
Trisomy 18
Very low PAPP-A, low hCG, increased nuchal translucency
Trisomy 13
Low AFP, uE3
High hCG, Inh A
Trisomy 21
Low AFP
VERY LOW uE3, hCG
Trisomy 18
Which test has lowest false-positive rate for non-invasive tests in pregnancy
Full integrated test. US measurement of nuchal translucency, serum measurement of pregnancy-associated plasma protein A in first trimester and quad screen in second trimester
What does the quad screen consist of
Maternal serum aFP
Estriol (uncojugated)
hCG
Maternal serum inhibin A
Which screening test is performed in all pregnant women at 16-18 weeks gestation
Quad screen
Which screening can determine karyotype
Amniocentesis
When is chorionic villi sampling performed
Early detection of chromosomal abnormalities in higher risk patients (advanced age, hx of children wit genetic defects)
What are the indications for percutaneous umbilical blood sampling/cordocentesis
Second and third trimester when karyotype results are required within a few days
Diagnosing fetal hyper- or hypothyroidism
Diagnosing and managing fetal thrombocytopenia
Nagele’s rule
LMP + 7 days - 3 months + 1 year = estimated delivery date.
Cardiac defect associated with gestational DM
Transposition of great vessels
BP i npre-eclampsia
> 140/90
A rise in creatinine during pregnancy should make you consider?
Pre-eclampsia
BP meds used in pregnancy
Methyldopa Labetalol Hydralazine Nifedipine/amlodipine Thiazides (Avoid volume depletion!)
Why is mag sulfate used in pre-eclampsia
Prevent seizures (NOT FOR BP!!!)
What do we use to treat eclampsia?
Mag sulfate and IV diazepam and continue for 48 hours following delivery!!
What happens if your patient is on mag sulfate and starts having seizures?
Give more mag sulfate
How long do we continue mag sulfate in PRE eclampsia
24 hours post-delivery
Epilepsy tx in pregnancy
Keep them on their AED but also should be given supplemental vitamin K (only during last month of pregnancy to prevent PPH) and folate.
How is hyperemesis gravid arum distinguished from normal morning sickness
Weight loss exceeding 5% of pre pregnancy body weight and detection of ketonuria due to starvation
Workup in a patient wit hyperemiis gravidarum
WEight, orthostatic
Serum free T4, serum electrolytes, urine ketones
Ulrasound to detect gestational trophoblastic disease and multiple gestations
Expected non worrisome lab abnormalities associated with vomiting in prego
Elevated AST and ALT (but
Tx of UTI in pregnancy
Amoxicillin
Nitrofurantoin
Ceftriaxone
Which opioid is more likely to have increased teratogenic effects in neonate
Methadone
How do you treat migraines in pregnancy
Hydrocodone (opioids!) I HAD THIS Q ON COMLEX LEVEL 1
Radiation dose considered safe in pregnancy
Less than 0.05 (5 rads)
Risk of malformations increases after 0.10 gray
Which AED causes fingernail hypoplasia
Carbamazepine
Which rx drug associated with cleft palate
Diazepam (maybe also phenytoin)
Effect of sulfonamides during pregnancy
Kernicterus
Which rx drug associated with Dandy Walker malformation
Warfarin
Which rx drug associated with hypospadias
Valproic acid
Anti-viral contraindicated in prego
Ribavirin
Which congenital infection associated with high risk of neonatal death if disease transmission occurs?
Rubeola (measles)
When should you provide intrapartum antibiotic prophylaxis for GBS
GBS bacteriuria during current pregnancy
History of early onset GBS in a previous infant
Intraoartum fever
Preterm labor (18 hrs)
When can methotrexate be used in the treatment of ectopic pregnancy rather than surgical removal?
Hemodynamicaly stable
Reliably compliant with post-treatment monitoring
Pretreatment serum hCG
At what hCG level should you be able to see an intrauterine pregnancy on transabdominal US
6500 mIU/mL
At what hCG level should you be able to see transvaginal US intrauterine preg
1500 mIU/mL
Which congenital infection is initially asymptomatic but later develops a unilateral hearing loss
CMV
Which congenital infection associated wit hhydrocephalus, intracranial calcifications and chorioretinitis
Toxo classically but also could be CMV
Which congenital infection associated with hearing loss, chorioretinitis, and intracranial calcifccations
CMV
Which congenital infection associated with PDA or pulmonary artery stenosis
Rubella
1st line tx for hyperemesis gravidarum
Vitamin B6
Docsalamine (unasom)
Hydration
Which teratogen gives craniofacial defects, IUGR, CNS malformation and stillbirth
Warfarin
Which teratogen causes hydrocephalus, CNS defects, craniofacial, ear and cardiovascular defects
Isotretinoin
Which teratogen causes cerebral infarcts, mental retardation
cocaine
Initial US finding for IUGR
Abdominal circumference
Definition of oligohydramnios
AFI
Definition of polyhydramnios
AFI>25 cm on ultrasound
Oligohydramnios in 3rd trimester
premature rupture of membranes
Mag sulfate is contraindicated when?
In myasthenia gravis
Reversal agent for mag sulfate
Calcium gluconate
Early decels are a sign of
Head compression
LAte decals are a sign of
uteroplacental insufficiency
Fetal hypoxia
Variable decals are a sign of
Umbilical cord compression
What should you do if you see variable decels
Change moms position
What should you do if you see late decels
Test fetal blood from scalp sample to dx hypoxia or acidosis
Recurrent late decals or fetal hypoxia direct PROMPT DELIVERY
Nml fetal heart rate
120-160 bpm
Non-stress test – what is moms position
Left lateral supine
Define a reactive nonstress test
two or more 15 bp accelerations of fetal heart rate lasting at least 15 seconds within 20 minutes
Non-reactive nonstress test prompts?
Biophysical profile
Components of biophysical profile
Nonstress test repeated
Ultrasound to measure AFI
Fetal breathing, movement, and tone (extension of fetal spine or limb with return to flexion)
Reassuring biophysical profile
8-10
Reassuring contraction stress test
Beat to beat variability of ~5 bp
Long-term heart rate variability
Occasional heart rate accelerations (2+ access of 15 bp lasting at least 15 seconds within a 20 minute period)
Abnormal 3 hour 100 g fasting glucose test
95 mg/dL
Abnormal 1 hour 50 g oral glucose test
140 mg/dL
Abnormal 3 hour 100 g oral glucose test at 1, 2, and 3 hours
180 mg/dL
155 mg/dL
140 mg/dL
Cervical dilation: bishop scoring
For 0 cm: 0 points
For 1-2 cm: 1 point
For 3-4 cm: 2 points
For 5-6: 3 points
Effacement: bishop scoring
For 0-30%: 0 points
For 40-50%: 1 point
For 60-70%: 2 points
For 80%: 3 points
Station: bishop scoring
For -3 station: 0 points
For -2 station: 1 point
For -1 and 0 station: 2 points
For +1 and +2 station: 3 points
Consistency: bishop scoring
For firm: 0 points
For medium: 1 point
For soft: 2 points
Position: bishop scoring
Posterior: 0 points
Mid: 1 point
For anterior: 2 points
Normal cervical dilation for primp during active phase
1.2 cm per hour
Normal cervical dilation for multi during active phase
1.5 cm/hr
Normal latent phase length in primip
20 hours
Normal latent phase length for multip
14 hours.
What causes the changes in the cervix during labor
Breakage of disulfide bonds in collagen (mediated by prostaglandin E2, stimulated by engagement)
What is the station when the fetal head has engaged the cervix?
-2. This is engagement, when the fetal head contacts the cervix and tells it to start ripening.
Frank breech
Knees are extended, hips flexed
Adequate contractions
CTX 3 in 30 min
>40 mm Hg
A prolonged phase III in labor puts mom at higher risk for ?
PPH. If the uterus is too tired to push out a placenta, its probably too tired to calm down and prevent PPH.
Most common cause of premature ROM?
Ascending infection. Give her abx.
Most common cause of ppROM?
Ascending infection. If
Define prolonged ROM
> 18 hours from ROM to delivery. Increased risk of GBS infection.
Abx used for prom/pprom + fever
Broad spec, usually pip-tazo
4 things that can delay delivery
Mag sulf
B agonists (like terbutaline)
CCB (like nifedipine)
Prostaglandin inhibitors like ketorolac or indomethacin
Next step if you think baby might be post-date?
If you’re unsure of dates, perform biophys profile.
In twin gestation, with 2 placentas, the twins are ?
Monozygotic
Diamniotic
Dichorionic
What if theres only 1 plant in twin gestation?
Check the septum which would separate the sacs.
If there is one placenta, and at least 1 septum in a twin gestation, the twins are?
MONO zygotic
MONO chorionic
DIamniotic
If there is 1 placenta and NO sept in a twin gestation, the twins are ?
Monozygotic
Monochorionic
MMonoamniotic
When did split occur for monozygotic, dichorionic, diamniotic twins?
0-3 days after fertilization, in the tubal phase.
When did split occur for monozygotic, monochorionic diamniotic twins?
4-8 days after fertilization, in blastocyst phase
Extra risk associated with monozygotic monochorionic diamniotic twins?
Twin twin transfusion, since they share a placenta.
When did split occur for mono mono mono twins?
9-12 days after fertilization.
If > day 12, most likely conjoined :(
Extra risk associated with mono mono mono twins?
Cord entanglement.
Tx of uterine inversion
Tack down fornices, give pitocin since its bleeding.
Next step after an in-between BPP and baby is
Contraction stress test using pitocin. Looking for LATE DECELS.