OB Exam Review

How is the estimated due date calculated?

Nageles Rule:

First day of LMP - 3 months + 7 days + 1 year

Know how to do GPA classifications

Gravida = # times pregnant

Para = # of births

Subcategories of para:

Full term

Premature

Abortions

Living children

How many para do twins count as?

One

Ex: first time pregnant mother gave birth to twins full term

G1 P1002 (2 for 2 kids)

At how many weeks is the fundal height palpable

8 weeks

At how many weeks does the fundus become an abdominal organ

12 weeks

At how many weeks is the fundus at the umbilicus

20 weeks

At how many weeks does the uterus decrease in fundal height

36-40 weeks (baby "drops")

At how many weeks is the fundus at the midpoint between pubic symphysis and umbilicus

16 weeks

At what weeks will the fundal height correlate with gestational age

26-34 weeks

When would you go with the ultrasound gestational age vs LMP?

US > 1 wk off than LMP in first trimester

US > 2 wks off than LMP in 2nd trimester

US > 3 wks off than LMP in 3rd trimester

What is Leopold's first maneuver used to determine?

Superior side:

- consistency

- shape

- mobility

What is leopolds second maneuver used to determine?

direction the back is facing

What is leopolds third maneuver used to determine?

What part of the fetus is at the inlet

What is leopolds 4th maneuver used to determine

Degree of fetal extension into pelvis

What screening is done to screen for chromosomal abnormalities? When is it done?

MaterniT21 btwn 10 and 20 weeks

T/F MaterniT21 can evaluate neural tube defects

FALSE

when is the Maternal Serum alpha fetoprotein test performed? What does it look for?

15-21 weeks

Looks for risks of neural tube defects

When is the simple glucose challenge test (GCT) done?

24-28 weeks

What should you do if the simple GCT is positive?

+ if >140 1 hr post 50 g of glucose

Do 3 hr hour GTT if +

When is group B strep screened for during pregnancy?

Vaginal swab @ 35-37 weeks

Tx w/ penicillin if +

What are the trimesters?

1st -> conception to 12 weeks

2nd -> 13 - 28 weeks

3rd -> 28 weeks to delivery

What vaccines should not be given during pregnancy?

LIVE:

- MMR

- Yellow fever

- BCG

- Varicella

- Oral polio

What vaccines SHOULD be given in pregnancy? When?

Flu: flu season

Tdap: 27-36 weeks

What vitamin should be started prenatally to avoid neural tube defects?

Folate

What samples are collected in integrated screening

2 blood samples: one from 1st trimester and one from 2nd

What is a normal fetal HR and what does it look like on a NST

120-160

Normal: small squiggles

What do decelerations look like on NST?

Drops/ V or W pattern

Effacement vs Dilation

Effacement: shortening of the cervix (%)

Dilation: diameter of the os (in cm)

What is the distance of the fetus in relation to the ischial spines called?

Station, measured in cm

What does the umbilical arteries and vein carry

Arteries: deoxygenated blood to placenta, from baby

Vein: oxygenated blood to baby, from placenta

How does estrogen affect cortisol levels

Increases plasma cortisol levels

What happens to GFR levels, CrCl, plasma renin and angiotensin levels during pregnancy

Increased

What happens to BUN, serum creat, and uric acid levels during pregnancy

Decreased

T/F: pregnancy can crease respiratory alkalosis d/t mild hyperventilation

TRUE

Dec CO2, Inc pH

when is DVT risk the highest during pregnancy?

Delivery - 6 weeks postpartum

What hormone is responsible for inc risk of cholelithiasis in pregnancy

Estrogen

Progestin causes cholestasis

What hormones are responsible for insulin resistance during pregnancy

-Resistin

-human placental lactogen

-cortisol

-estrogen

MC cephalic presentation

Left occipital anterior (LOA) vertex

(Baby is looking down to the right)

Cardinal Movements of labor

ED FIRE REx

Engagment

Descent

Flexion

Internal Rotation

Extension

Restitution (external rotation)

Expulsion

4 degrees of perineal tears

1st: skin/mucosal break

2nd: submucosa

3rd: anal sphincter

4th: through sphincter, into rectal mucosa

MC risk of shoulder dystocia

Macrosomic (big) babies (GDM)

APGAR scoring

What are the universally mandated newborn screenings

PKU and hypothyroidism

Routine newborn prophylaxis

Silver nitrate & erythromycin for gonn/chlamydial blindness

Hep B vax

Screen for bilirubin if jaundice

MCC of excessive postpartum bleeding

uterine atony

Contraindications to breastfeeding

- HIV, CMV, areolar HSV

- galactosemia in infant

- maternal need for CI drug

+/- Hep B/C

First line rx for BV and trichomonas

Metronidazole

BV is after 1st trimester

First line rx for syphilis

PCN

First line rx for chlamydia / gonorrhea

Chlamydia: azithromycin (NO DOXY IN PREG)

Gonorrhea: Rocephin

First line rx for HSV

Oral suppressive therapy at 35-36 weeks

C-Section if active lesions

First line rx for candidiasis

Miconazole cream

What is considered chronic HTN in pregnancy

BP > 140/90

Before 20 wks or after 20 wks x 12 wks PP

Treatment of choice for chronic HTN

Methyldopa

What is considered gestational HTN

140/90 after 20 weeks but NORM within 12 weeks PP

What is considered pre-eclampsia? How to dx?

BP >140/90 + proteinuria on UA dipstick / 300 ml per day

How to treat severe preeclampsia or eclampsia

Hydralazine + Mg sulfate + delivery

Lorazepam for seizures in eclampsia

BP goal in preeclampsia

BP < 160 / 105-110

BP > 160/110 = severe preeclampsia

What is HELLP syndrome?

Hemolysis

Elevated LFTs

Low Platelets

>> can result in DIC

What is considered eclampsia

Preeclampsia + seizure / coma

Best dx for eclampsia

24 hr urine (protein)

>300mg mild

>5g severe

Causes of gestational diabetes

-human placental lactogen

-cortisol

-human GH

RF of developing gestational DM

Excessive weight gain

FMHx

Prior baby >9 lbs

Maternal and fetal risks of gestational DM

Maternal: inc risk for T2DM

Fetal: shoulder dystocia

GS dx of GDM

3hr GTT (100g)

Screening with 50g OGTT @ 24-28 wks

Management of GDM

Class A1: diet

Class A2: insulin IF...

- FBG >100

- post prandial glucose >140

What increases risk of transmission of GBS

-prematurity

-maternal fever intrapartum

-prolonged membrane rupture

-PMHx of GBS

Prevention of GBS

Swab @ 36-37 wks

PCN / AMP @ delivery if +

What fetal infections can occur if GBS is transmitted

Meningitis

PNA

Sepsis

Presentation of congenital rubella

Deafness

Vision impairment

Neuro / cardio defects

Mental retardation

Microcephalic

2 day old infant presents with microcephally, failed the hearing test, and a purple maculopapular rash. What was most likely transmitted to the baby and how do you treat?

CMV

Tx with ganciclovir

Fetal risks of varicella infection

Limb hypoplasia

Cutaneous scarring

Mental retardation / CNS abnormalities

Transmission and treatment of toxoplasmosis

Cat poo

Tx: spiramycin +/- sulfadiazine

What can fetal transmission of parvovirus cause

Fetal hydrops d/t infected reticulocytes

Does Rh isoimmunizatoin affect the first pregnancy?

NO > IgM forms in first preg

IgG forms in second which causes erythroblastosis fetalis (RBC hemolysis)

Presentation of Rh isoimmunization

Term preg: 300 mcg RhoGAM @ 28 wks & 72 hrs of delivery

1st trimester abortion/miscarriage: 50 mcg MICRogam

What is the accumulation of fluid in 2 or more fetal compartments

Hydrops fetalis

Results in 60-90% fetal mortality

What is considered macrosomnia? What are the RF?

BW > 4000 g

RF: inc maternal BMI, excess maternal weight

What are the 4 types of teratogens?

Radiation

Pharmaceuticals

Infection (TORCH)

Chemical (metals, pesticides)

What are the known pharmacological teratogens (6)

Isotretinoin

MTX

VPA

Tetracyclines (doxy)

ACEs

Live Vaxes

7 layers of closure of a c section

1: uterus

2: uterus again (needed for future vaginal births)

3: visceral peritoneum

4: parietal peritoneum

5: fascia

6: subQ tissue

7: skin

Bold is required

Down syndrome

Trisomy 21

Edward's syndrome

Trisomy 18 (10% chance of survival)

Patua Syndrome

Trisomy 13 (10% survival)

Presents with cardiac probs

MC sex chromosomal abnormality in females

Turner's syndrome (absence of an x - 45X)

How does Turner's syndrome present

Wide set nipples

Webbed neck

Short stature

Primary hypogonadism

Jacob's syndrome presentation

Extra Y >>

Phenotypically male, underdeveloped testes and breasts, learning disabilities

Klinefelter syndrome presentation

Extra X in males >>

-gynecomastia

-micropenis

-hypergonadotropic gonadism

MCC of pregnancy related death in 1st trimester

ectopic pregnancy

MC location of ectopic pregnancy

Ampulla of the fallopian tubes

Presentation of ectopic pregnancy

- pelvic / abd pain

- AUB

- palpable mass

- cervical tenderness

- syncope / dizziness

How long does it take an ectopic pregnancy to rupture?

Isthmic: 6-8 wks

Ampullary: 8-12 wks

Interstitial: 12-16 wks (hemorrhagic)

Pt presents with high HCG levels and US reveals an empty uterine cavity... what is the most likely diagnosis?

Ectopic pregnancy

When should an intrauterine sac be visible on US

Transvag: HCG >1000

Abd: HCG 1800-3600

Treatment for stable and unstable ectopic pregnancies

stable: MTX

Unstable: emergency surgery

What is the definitive management of ectopic pregnancies

Laparoscopy

Intrauterine bleeding before 20 weeks is known as

Threatened abortion

>> no dilation of cervix

Intrauterine bleeding before 20 weeks WITH cervical dilation

Inevitable abortion

What is considered a missed abortion

Embryo dies but POC is retained

MCC of spontaneous abortion

Aneuploidy

Treatment of abortion before 20 wks

Misoprostol +/- mifepristone