OB Flashcards
What do the TPAL of Parity stand for?
Term: deliveries between 37 and 42 weeks Preterm: between 20-37 weeks **considered viable after 23 weeks Abortion: spontaneous or induced prior to 20 weeks Living: living children
How long does pregnancy last
280 days
40 weeks
Technically when does the post partum period end?
6 weeks after delivery
Nagele’s Rule
Due date: add 7 days to last menstrual period and subtract 3 months
ex. LMP: 2.20.18, EDD: 11.27.19
Gestational age
age of fetus calculated from 1st day of LMP (includes 2 weeks when woman is not pregnant
Fetal age
age of fetus calculated from time of implantation.
Gestational age - 2 weeks
Which trimester are fetus most sensitive to teratogens?
1st trimester
Embryo timeframe
fertilization to 8th week of pregnancy
How are the trimesters broken up?
First trimester: 1-12 weeks
Second trimester: 13-28 weeks
Third trimester: 28-40 weeks
What is the recommendation for folic acid supplementation for low risk and high risk?
low risk: 0.4 mg
high risk: 4 mg
*start these prior to pregnancy
What is the hCG level around the time of missed menses?
~25. Then increases exponentially for 10 weeks then plateaus
Progesterone secretion in early pregnancy
Corpus luteum makes for ~6 weeks
Placenta makes progesterone after 6 weeks
How much does beta hCG increase in a normal pregnancy
doubles every 48 hours
-this is responsible for nausea and vomiting
Goodell’s Sign
softening of the cervix
-4-6 weeks gestation
Hegar’s Sign
softening of uterine isthmus
-6-8 weeks gestation
Chadwick’s Sign
bluish discoloration of cervix
-8-12 week’s gestation
Initial OB Visit
Labs: CBC, Blood type and Rh, Rubella, Syphilis, Hep B antigen, HIV, Chlamydia and gonorrhea cultures
When can fetal heart activity be detected?
5-6 weeks
When is the Quad screen done?
2nd trimester
- Blood testing
- AFP, hCG, Estriol, Inhibin-A
- Increased AFP -> neural tube defects, multiple gestations
- Abnormal tests (all 4) –> trisomy 18 or 21
When is Chorionic Villus Sampling done?
1st trimester (extracts placental cells)
When is Amniocentesis done?
2nd trimester (extract amniotic fluid)
Frequency of visits
initial: 6-8 weeks after LMP
Monthly for 1st and 2nd trimesters
Bimonthly 28-36 weeks
Weekly 36 weeks - delivery
Fetal heart tones
120-160 bpm is normal
When do you begin measuring fundal height?
20wks
When do you start cervical exams?
37 wks
When you measure fundal height at the umbilicus what is the gestational age?
20 weeks = umbilicus
When do you need to screen for gestational diabetes?
24-28 weeks
When do you do repeat antibody screen for Rh negative women
26-28 weeks
When is hemoglobin and hematocrit screened?
3rd trimester
-35 weeks
When do you perform group B strep screen?
35-37 weeks
How many 3 hour Glucose Tolerance tests need to be abnormal to diagnose gestational diabetes?
2 or more
If a women that is Rh (negative) when do you administer RhoGAM?
28 weeks
-attaches to Rh antigen preventing mothers immune system from attacking fetal red blood cells
What is the best treatment for a women with group B strep giving vaginal delivery?
Ampicillin IV
or
Clindamycin (if PCN allergic)
Why do pregnant ladies need to avoid deli meat, hot dogs and soft cheese during pregnancy?
Listeria monocytogenes
Why do pregnant ladies need to avoid raw milk and cheese?
Brucellosis
Which vaccines should pregnant ladies get?avoid?
Do: Tdap and Flu
Don’t: Live vaccines; MMR, varicella
Presenting parts
Vertex: head
Breech: feet
Transverse, Compound –> c-section
Acceleration: abrupt increase in heart rate from baseline
reassuring sign of fetal well being
Variable deceleration: abrupt decrease in heart rate from baseline
extremely common
Late deceleration: gradual symmetrical decrease in heart rate
may indicate fetal distress (ex. fetal hypoxia, maternal hypotension)
What can be given if there is hypocontractile uterine activity
give pitocin
What is the most common complication of early pregnancy?
Abortion (chromosomal abnormalities ~50%)
Abortion Types
Threatened: vaginal bleeding + closed cervix
Inevitable: vaginal bleeding + open cervix
Missed: pregnancy retained despite death of fetus
What drug induces uterine contractions and is used to expel conceptus with abortion?
Misoprostol (prostaglandin analogue)
Septic Abortion: Tx
- Hospitalize
- IV antibiotics (cefoxitin and Doxycycline)
What is the medical regimen for an elective abortion?
- Mifepristone (day 1)
- Misoprostal (day 2 or 3)
**Used only for <70 days gestation
Elective abortion: surgery 1st versus 2nd trimester
1st trimester: suction curettage
2nd trimester: Dilation and evacuation
Where do most ectopic pregnancies occur?
fallopian tube (mostly the ampullary portion)
Ectopic pregnancy: Tx
- Give RhoGAM in Rh (-) women
- Methothrexate IM
(hCG needs to be below 5000, no cardiac activity for this to work)
What is the diagnosis if the patient has a large uterus, no fetal heart tones, hyperemesis and pre-eclampsia like symptoms prior to 20 weeks with “snow storm” within endometrium
Gestational trophoblastic disease
What is the most common type of gestational trophoblastic disease and which ethnic groups are susceptible?
- Hydatiform mole
- Asians and American Indians
If your patient has a hydatiform mole, what patient education do they need to get?
Avoid pregnancy for 12 months
With a placenta previa (covering the cervical os) what must you NEVER do?
Never perform cervical exam —>hemorrhage!
-avoid intercourse
Painful bleeding versus Painless bleeding after 20 weeks?
Painful –> placental abruption
Painless –> placenta previa
What are some risk factors for premature rupture of membranes?
- Genital tract infection (bacterial vaginosis)
- smoking
What is the treatment for premature rupture of membranes?
corticosteroids to promote lung maturation <34 weeks
What is a classic diagnostic finding in sample fluid from premature rupture of membranes?
“ferning” under microscope
What is the most common cause of post-partum hemorrhage?
uterine atony (lack of contractons so blood vessels are constricted)
What is the treatment for post-partum hemorrhage?
- uterine massage
- IV fluids
- Oxytocin/misoprotol/methergine
Most twins are monozygotic (identical) or dizygotic (fraternal)?
dizygotic “fraternal twins”
-2 amniotic sacs
In the 1st trimester you see a “lamda sign” on US, what does this indicate?
Dichorionic twins (fraternal)
What does a “T sign indicate?
Monochorionic twins (identical)
When does pregnancy-induced HTN technically occur?
> 20 weeks (no proteinuria)
Pre-eclampsia
- New onset HTN and proteinuria after 20 weeks
mild: BP >140/90, AND 0.3 or more protein in 24 hr urine specimen
Severe: BP >160/110
(need 2 separate readings)
Eclampsia
seizures in a women with pre-eclampsia
In a pre-eclampsia patient when is medication indicated and which HTN meds do you use?
Use if >160/110
IV labetalol or hydralazine