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OB/GYN Guidelines Cheat Sheet by

Guidelines and screening for rotation


Defini­tion: failure to conceive after one year of regular, unprot­ected interc­ourse.
Etiology: males 40% - abnormal sperma­tog­enesis. Females - anovul­atory cycles or ovarian dysfun­ction = 30%, congenital or acquired disorders.
DX: hyster­osa­lpi­ngo­graphy to evaluate tubal patency or abnorm­ali­ties.
Manage­ment: 1. Clomiphene — induces ovulation. 2. If amenorrhea or oligom­eno­rrhea, correct endocrine problems. 3. In vitro fertil­ization

Uncomp­licated Pregnancy Physical Exam

Ladin’s sign
Uterus softening after 6 weeks
Hegar’s sign
Uterine isthmus softening after 6-8 weeks
Piskacek’s sign
Palpable lateral bulge or softening of uterine Cronus 7-8 weeks
Goodell’s sign
Cervical softening due to increased vascul­ari­zation, 4-5 weeks
Chadwick’s sign
Bluish coloration of cervix and vulva, 8-12 weeks
Fetal Heart tones
10-12 weeks, normal = 120-160 bpm
Pelvic Ultrasound
Fetus detected 5-6 weeks
Fetal Movement
16-20 weeks

Fundal Height Measur­ement

12 weeks
Above pubic symphysis
16 weeks
Midway between pubis and umbilicus
20 weeks
At umbilicus
38 weeks
2-3 cm below diploid process

Prenatal Care

Estimated Date of Delivery (Naegle’s Rule) : 1st day of LMP + 7 days - 3 months
Blood pressure
Blood type & Rh
UA (glucose & protein)
Random glucose
HBsAg — hepatitis surfaced antigen, measures acute or chronic
Rubella Titer
Sickle cell and cystic fibrosis screen
PAP smear

Rh Alloim­mun­ization

Rh(D) negative women carry Rh(D) positive fetus —> exposure to fetal blood mixing D-positive RBCs
Causes maternal alloim­mun­ization and maternal anti-Rh(D) IgG antibodies
Subsequent pregna­ncies —> antibodies may cross placental and attack fetal RBCs = hemolysis of fetal RBCs
If mother is Rh(D) negative and father is Rh(D) positive, 50% chance
Anti-D Rh immuno­glo­bulin (RhoGAM) 300 micrograms given @ 28 weeks, within 72 hours of delivery of Rh(D) positive baby, AND after any potential mixing of blood (spont­aneous abortion, ectopic pregnancy, amnioc­ent­esis, etc.)

First Trimester Screening: Weeks 1-12

Free beta-hCG
Abnormally high or low may indicate chromo­somal abnorm­alities
Serum pregna­ncy­-as­soc­iated plasma protein-A — Low with fetal Down syndrome
Nuchal transl­ucency US
10-12 weeks — trisomies 13, 18, and 21. Increased thickness = abnormal, offer chorionic billows sampling or amnioc­ent­esis.
Fetal US
10-12 weeks , transv­aginal can detect at 5-6 weeks after LMP
Uterine size and gestation
If abnormal, offer CVS or amnioc­entesis
10-13 weeks if abnorm­alities or if at increased risk of abnorm­alities (>35 yo)

Second trimester screening: Weeks 13-27

Triple screening @ 15-20 weeks
Alpha-feta protein: if high, indicates open neural tube defects / spina bifida. Beta-hCG: high = Down syndrome/ trisomy 21, low = trisomy 18. Unconj­ugated Estriol: often low in trisomy 21 and 18.
Gestat­ional Diabetes @ 24-28 weeks
1 hour & 3 hours abnormal = >140

Third Trimester Screening: Weeks 27-birth

Repeat antibody titers
In RH(D) negative, antibody negative —> give RhoGAM 300 micrograms @ 28 weeks
Hemoglobin & Hematocrit
35 weeks
Group B Strept­ococcus
36 0/7 to 37 6/7 weeks, if positive —> prophy­lactic abx during labor w/in 4 hours of delivery with IV PCN G 5 million units, then 2.5 million units every 4 hours. Second line = Ampici­llin, Cefazolin, Clinda­mycin, Vancomycin
Biophy­sical Profile
Fetal breathing, fetal tones, amniotic fluid levels, NST, and gross fetal movements (2 points each)
Non-stress testing
Reactive Test: >/= 2 accele­rations of fetal HR >/= 15 bpm from baseline lasting 15 seconds over 20 minutes — fetal well being, repeat weekly­-bi­weekly. Nonrea­ctive test: No fetal HR accele­rations or </= 15 bpm lasting < 15 s— indicates sleeping, immature, or compro­mised fetus —> vibratory stimulus to wake or contra­ction stress test.
Contra­ction Stress Testing
Negative test: No late decele­rations in presence of 3 contra­ctions in 10 minutes = fetal well being. Positive CST: repetitive late decele­ration following >/= 50% of contra­ction = worrisome, hospit­alize for fetal monitoring or delivery.

Intra Partum (onset of labor-­del­ivery of placenta)

Braxton Hicks
Sponta­neous uterine contra­ctions late in pregnancy not associated with cervical dilation
Fetal head descending into the pelvis causing a change in abdomen’s shape and sensation
Ruptured Membranes
Sudden gush of liquid or constant leakage of fluid
Bloody Show
Passage of blood-­tinged cervical mucus late in pregnancy, occurs with cervix is thinning (effac­ement)
True Labor
Contra­ctions of uterine fundus with radiation to lower back & abdomen. Regular + painful contra­ction of uterus causes cervical dilation and fetus expulsion

Cardinal Movements of labor

When the fetal presenting part enters the pelvic inlet
Passage of the head into pelvis (light­ening)
Flexion of head to allow smallest diameter to present to pelvis
Internal Rotation
Fetal vertex moves from occiput transverse position to position where the Sagitt­arius suture is parallel to the antero­pos­terior diameter of pelvis
Vertex extends as it passes beneath the pubic symphysis
External Rotation
Fetus externally rotates after the head is delivered so that the shoulder can be delivered
Of fetus and placenta

Stages of Labor

Stage 1: Onset of labor (true contra­cti­ons­-ce­rvical dilation @ 10 cm
Latent phase: cervix effacement with gradual cervical dilation. Active Phase: rapid cervical dilation (begins @ 3-4 cm)
Stage 2: full dilati­on-­del­ivery of fetus
Passive Phase: complete cervical dilation to active maternal expulsive efforts. Active phase: from active maternal expulsive effort­s-d­elivery of fetus.
Stage 3: postpartum until delivery of placenta (0-30 mins)
Signs of placental separa­tion: 1. Gush of blood. 2. Length­ening of umbilical cord. 3. Anteri­or-­cap­halad movement of uterine fundus (becomes globular and firm) after placenta detaches.
Stage 4: after delivery
Mother is assessed for compli­cat­ions, 1-2 hours after


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