OB 5 Flashcards
- Rh+ means what?
- Rh- means what?
- Rh incompatibility is referred to as what?
- Rh+ = D antigen is present
- Rh- = D antigen is absent***
- Alloimmunization (maternal immune system exposed to Rh+ RBC from fetus. Incidence ↑ w/ subsequent pregnancies)
Rh antigens can cross placenta freely. Rh- mother develops antibodies to the Rh+ antigens. Maternal antibodies do what?
Maternal antibodies cross the placenta and fetal RBC hemolysis occurs (causes fetal death)
What is the method of prevention for Rh- moms?
RhoGAM is Rh immunoglobulin which attaches to Rh+ antigen and prevents mother’s immune response
RhoGAM is only administered to mother who are not what?
Alloimmunized (maternal immune system already exposed to Rh+ RBCs)
When is RhoGAM given?
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
What are the 2 main risks to the fetus w/ Rh Incompatibility?
- Anemia
- Hyperbilirubinemia
Hemolytic Disease of the Newborn
Erythroblastosis Fetalis (Anemia) d/t Rh Incompatibility
Edema, cardiac failure
Severe and often fatal in utero
Hydrops Fetalis (anemia d/t Rh Incompatibility)
Toxic levels of unconjugated bilirubin
Kernicterus (hyperbilirubinemia d/t Rh Incompatibility)
Physiologic Jaundice of newborn
Hyperbilirubinemia (d/t Rh Incompatibility)
How should you manage maternal alloimmunization?
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)
What is the tx for Hemolytic Disease of Fetus or Newborn (HDFN)?
Intrauterine Transfusion
Early delivery
Which type of breech?
- Both hips flexed with knees extended so feet are adjacent to head (50 -70%)
Frank Breech
Which type of breech?
- Both hips and knees are flexed (5 -10%)
Complete Breech
Which type of breech?
- One or both hips are NOT completely flexed (10 – 40%)
Incomplete Breech
What is the MC type of breech?
Frank (both hips flexed & knees extended)
When during gestation do most breech presentations occur?
Prior to 28 weeks (25%)
Next MC is 32 weeks (16%)
Only 3-4% occur at term
What are some RF of Breech?
◦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)
How is breech diagnosed? (2)
- Palpate soft mass (buttocks) in the lower uterine segment (absence of fetal skull)
- US will confirm fetal head at the fundus
What is treatment for breech presentation?
(2)
- External cephalic version at 34-35 weeks (usually does not work)
- C-section (this is usually the tx)
What is cord prolapse?
Umbilical cord slips AHEAD of the presenting part of fetus, protruding into the cervical canal/vagina
Cord Prolapse is considered an obsterical emergency since the cord is vulnerable to compression causing what 3 things?
- Umbilical vein occlusion
- Umbilical artery vasospasm
- ↓ fetal oxygenation
What is the etiology of cord prolapse?
High outward flow of amniotic fluid vs. disengagement of presenting part
How is cord prolapse diagnosed? (2)
Visualization
Palpation of umbilical cord ahead of presenting part
What are the 5 maternal RF of cord prolapse?
- Prolonged labor
- low lying placenta
- pelvic deformities
- uterine anomalies
- polyhydramnios
What are the 4 fetal RF of cord prolapse?
- prematurity
- malpresentation
- low birth weight
- second twin
What are 6 obsterical interventions which can cause cord prolapse?
- 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
What is tx for Cord Prolapse
Emergent C-section
Describe a Cesarean Section?
Delivery of fetus through incision in abd wall (laparotomy) & uterine wall (hysterotomy)
What is the MC type of C-section?
Low transverse cesarean section (incision made in lower uterine segment)
What would a “classical c-section” be performed?
Describe it.
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)
What are 6 indications for a C-section?
- Fetal distress
- Prior breech (incidence increases w/ each pregnancy)
- Transverse lie
- Dystocia or failure to progress (difficult to get baby out)
- Prior C-section (pt may not want “trial of labor or V-back”)
- Uterine malformations (placenta previa)
What is dystocia?
Cervix fails to dilate progressively over time and fetus fails to descend
What are the 3 etiologies of Dystocia?
- 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
3 RF of dystocia?
- Prolonged interval between pregnancies
- Primigravid birth
- Hx of multiple births
4 complications of Dystocia?
- Fetal death
- Resp depression
- Hypoxic ischemic encephalopathy
- Brachial nerve damage
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?
Dystocia
- Oxytocin
- Forceps
- Vacuum
- C-section (last resort)
