OB 5

Question 1

• Rh+ means what?
• Rh- means what?
• Rh incompatibility is referred to as what?

Answer 1

• Rh+ = D antigen is present
• Rh- = D antigen is absent***
• Alloimmunization (maternal immune system exposed to Rh+ RBC from fetus. Incidence ↑ w/ subsequent pregnancies)

Question 2

Rh antigens can cross placenta freely. Rh- mother develops antibodies to the Rh+ antigens. Maternal antibodies do what?

Answer 2

Maternal antibodies cross the placenta and fetal RBC hemolysis occurs (causes fetal death)

Question 3

What is the method of prevention for Rh- moms?

Answer 3

RhoGAM is Rh immunoglobulin which attaches to Rh+ antigen and prevents mother’s immune response

Question 4

RhoGAM is only administered to mother who are not what?

Answer 4

Alloimmunized (maternal immune system already exposed to Rh+ RBCs)

Question 5

When is RhoGAM given?

Answer 5

1st dose: 28 weeks (prophylaxis)

2nd dose: within 72 hours of delivery of Rh+ infant

Or… at time of:

• Amniocentesis
• Ectopic pregnancy
• Spontaneous or induced abortion
• Bleeding during pregnancy

Question 6

What are the 2 main risks to the fetus w/ Rh Incompatibility?

Answer 6

• Anemia
• Hyperbilirubinemia

Question 7

Hemolytic Disease of the Newborn

Answer 7

Erythroblastosis Fetalis (Anemia) d/t Rh Incompatibility

Question 8

Edema, cardiac failure

Severe and often fatal in utero

Answer 8

Hydrops Fetalis (anemia d/t Rh Incompatibility)

Question 9

Toxic levels of unconjugated bilirubin

Answer 9

Kernicterus (hyperbilirubinemia d/t Rh Incompatibility)

Question 10

Physiologic Jaundice of newborn

Answer 10

Hyperbilirubinemia (d/t Rh Incompatibility)

Question 11

How should you manage maternal alloimmunization?

Answer 11

As a PA you will not manage these patients. REFER to perinatologist!

They will follow maternal anti-D titers to assess risk for Hemolytic Disease of Fetus or Newborn (HDFN)

Question 12

What is the tx for Hemolytic Disease of Fetus or Newborn (HDFN)?

Answer 12

Intrauterine Transfusion

Early delivery

Question 13

Which type of breech?

• Both hips flexed with knees extended so feet are adjacent to head (50 -70%)

Answer 13

Frank Breech

Question 14

Which type of breech?

• Both hips and knees are flexed (5 -10%)

Answer 14

Complete Breech

Question 15

Which type of breech?

• One or both hips are NOT completely flexed (10 – 40%)

Answer 15

Incomplete Breech

Question 16

What is the MC type of breech?

Answer 16

Frank (both hips flexed & knees extended)

Question 17

When during gestation do most breech presentations occur?

Answer 17

Prior to 28 weeks (25%)

Next MC is 32 weeks (16%)

Only 3-4% occur at term

Question 18

What are some RF of Breech?

Answer 18

◦Pre-term gestation

◦Prior breech presentation

◦Uterine abnormality (fibroid, bicornuate uterus)

◦Placental abnormality (previa)

◦Multiparity

◦Extremes of fluid volume (↓ Vs ↑)

◦Advanced maternal age

◦Contracted maternal pelvis

◦Fetal anomaly (hydrocephaly, ancephaly)

Question 19

How is breech diagnosed? (2)

Answer 19

• Palpate soft mass (buttocks) in the lower uterine segment (absence of fetal skull)
• US will confirm fetal head at the fundus

Question 20

What is treatment for breech presentation?

(2)

Answer 20

• External cephalic version at 34-35 weeks (usually does not work)
• C-section (this is usually the tx)

Question 21

What is cord prolapse?

Answer 21

Umbilical cord slips AHEAD of the presenting part of fetus, protruding into the cervical canal/vagina

Question 22

Cord Prolapse is considered an obsterical emergency since the cord is vulnerable to compression causing what 3 things?

Answer 22

• Umbilical vein occlusion
• Umbilical artery vasospasm
• ↓ fetal oxygenation

Question 23

What is the etiology of cord prolapse?

Answer 23

High outward flow of amniotic fluid vs. disengagement of presenting part

Question 24

How is cord prolapse diagnosed? (2)

Answer 24

Visualization

Palpation of umbilical cord ahead of presenting part

Question 25

What are the 5 maternal RF of cord prolapse?

Answer 25

1. Prolonged labor 2. low lying placenta 3. pelvic deformities 4. uterine anomalies 5. polyhydramnios

Question 26

What are the 4 fetal RF of cord prolapse?

Answer 26

1. prematurity 2. malpresentation 3. low birth weight 4. second twin

Question 27

What are 6 obsterical interventions which can cause cord prolapse?

Answer 27

* **Iatrogenic rupture of membranes** * cervical ripening with **balloon catheter** * **induction** of labor * **manual rotation** of fetal head * application of **scalp electrode** * Application of **intrauterine pressure catheter**

Question 28

What is tx for Cord Prolapse

Answer 28

Emergent C-section

Question 29

Describe a Cesarean Section?

Answer 29

Delivery of fetus through incision in abd wall **(laparotomy)** & uterine wall **(hysterotomy)**

Question 30

What is the MC type of C-section?

Answer 30

Low transverse cesarean section (incision made in lower uterine segment)

Question 31

What would a "classical c-section" be performed? Describe it.

Answer 31

In cases of **pre-maturity** bc/ lower segment is not developed or if fetal position precludes its use (Vertical incision in upper contractile portion of uterus)

Question 32

What are 6 indications for a C-section?

Answer 32

1. Fetal distress 2. Prior breech (incidence increases w/ each pregnancy) 3. Transverse lie 4. Dystocia or failure to progress (difficult to get baby out) 5. Prior C-section (pt may not want "trial of labor or V-back") 6. Uterine malformations (placenta previa)

Question 33

What is dystocia?

Answer 33

**Cervix fails to dilate** progressively over time and **fetus fails to descend**

Question 34

What are the 3 etiologies of Dystocia?

Answer 34

* **Pelvis:** cephalopelvic disproportion (pelvis not large enough to allow infant to pass) * **Power:** inadequate uterine contractions (needed to dilate cervix & expel infant) * **Passenger:** abnormal fetal lie, presentation, or large head

Question 35

3 RF of dystocia?

Answer 35

* Prolonged interval between pregnancies * Primigravid birth * Hx of multiple births

Question 36

4 complications of Dystocia?

Answer 36

* Fetal death * Resp depression * Hypoxic ischemic encephalopathy * Brachial nerve damage

Question 37

Cervix fails to dilate and fetus fails to descend. Pelvis isn't large enough. Uterine contractions are not powerful enough. Fetus has large head. _What is dx and tx?_

Answer 37

**_Dystocia_** * Oxytocin * Forceps * Vacuum * C-section (last resort)