OB PLE Flashcards
Pelvis:
Anything below the linea terminalis
Bounded anteriorly by pubic bones, laterally by inner surface of ischial bones and posteriorly by sacral promontory
True Pelvis
Represents the shortest diameter of the pelvic cavity which is an important landmark in assessing level to which presenting part has descended
Ischial spines
Pelvis:
Anything above the linea terminalis
Bounded anteriorly by lower abdominal wall, laterally by iliac fossa
And posteriorly by lumbar vertebrae
False pelvis
2 important diameters in pregnancy
Obstetrical conjugate and diagonal conjugate
Shortest distance bet. Symphysis pubis and sacral promontory
Cannot be measured directly
Approximately 10cm
Obstetrical conjugate
Distance between midportion of sacral promontory to upper margin of symphysis pubis
True conjugate
Distance from lower margin of symphysis pubis to the sacral promontory
Can be assessed clinically
Approximately 11.5-12cm
Diagonal conjugate
Distance bet. the farthest two points of the pelvic brim over linea terminalis
Transverse Diameter
If the lowest part of occiput is at/below the level of the ischial spine
Engagement
Inadequate midpelvis/midpelvic contraction
Narrow sacrosciatic notch
prominent ischial spine
Convergent sidewalls
Pelvic outlet contraction
Bituberous diameter <8cm
Narrow suprapubic arch
Pelvis that is most suitable for normal delivery
Round shape
Sacral angle >90 inclined backwards
Gynecoid pelvis
Pelvic bones
Ischium
Pubis
Ilium
Sacrum
3 muscles of the pelvic floor
Covered by parietal layer of pelvic fascia
Levator Ani
Iliococcygeus
Pubococcygeus
Heart shaped pelvis, suprapubic arch <90,
More common in males
Android Pelvis
AP diameter > transverse diameter
Narrow sidewalls, wide inclination of sacrum, ischial spines not prominent
Anthropoid pelvis
Supports the pelvic organs
Controls the external anal sphicter through puborectalis
Stabilizes sacroiliac and sacrococcygeal joints through ischiococcygeus
Pelvic diaphragm
Most common type of malpresentation
Breech
Hips are flexed, knees extended over anterior surface of the body
Most common type
Ideal for vaginal delivery
Frank breech
Hips flexed and knees flexed
Complete breech
Hyperextension of fetal head
Occiput is at the same side
Mentum/chin is the presenting part
Face presentation
Military attitude
Head is partially flexed
Sinciput presentation
Neck is fully flexed, chin in contact with thorax
Vertex/Occiput presentation
Lateral deflection of the head in labor that the sagittal suture is not at midline
Asynclitism
Longitudinal axis of fetus to that of the mother
Fetal lie
Sagital suture approaches the sacral promontory
Anterior Asynclitism/Naegele’s Obliquity
Sagital suture approaches the symphysis Pubis
Posterior asynclitism
Irregular contractions with long intervals and same intensity
Does not radiate to lumbosacral area
Sedation stops contraction
False labor
Regular contractions with shortening intervals
Intensity increases
With cervical effacement and dilation
True labor
Most common injury associated with shoulder dystocia
Brachial plexus injury
Maneuver:
Remove legs from stirrups and sharply flexing them up onto the abdomen
Decreasing the angle of inclination
Flattens/straightens sacrum
McRobert’s Maneuver
Maneuver:
Cephalic relacement into pelvis followed by CS
Reversal of cardinal movements of labor
Zavanelli maneuver
Maneuver:
Insert hand under symphysis pubis, reach for the accessible shoulder and push towards anterior surface of chest
Rubin’s maneuver
Cardinal Movements of labor
(E-D-F-IR-E-ER-E) Engagement Descent Flexion Internal rotation Extension External rotation Expulsion
Maneuver:
Hand is used to exert forward pressure on the chin of the fetus through the perineum just front of the coccyx and other hand exerts pressure posteriorly against the occiput
Ritgen maneuver
Stages of labor:
Onset of regular contraction and ends at 4cm dilation
Nullipara: <20hrs
Myltipara: <14hrs
Stage 1: Latent phase
Stages of labor:
Starts at 4cm until complete cervical dilation
Nullipara: >1.2cm/hr
Multipara: >1.5cm/hr
Stage 1: Active phase
Functional Phases of Labor
Preparatory
Dilational
Pelvic Division
Active Phase of labor:
Predictive of the outcome of labor
4-6cm
Acceleration Phase
Active Phase of labor:
Measures the overall efficiency of the machine
7-8cm
Maximum Slope
Active Phase of labor:
Reflective of the fetopelvic relationship
8-10cm
Deceleration Phase
Lacerations of birth canal:
Involves the fourchette, perineal skin, vaginal mucous membrane
First Degree
Lacerations of birth canal:
Extends to the external anal sphincter
Third degree
Lacerations of birth canal:
Extends into the rectal mucosa
Fourth degree
Lacerations of birth canal:
Involves the fascia and perineal muscles
Second degree
Separation of placenta occurs at the periphery first
Blood collects between the membranes and uterine wall and escapes from vagina
Duncan
Detachement of placenta starts from the central portion
Blood does not escape externally until extrusion of the placenta
Schultze
Episiotomy:
Easier to repair
Heals better
Less postoperative pin
More likely to extend to rectum
Midline episiotomy
Episiotomy:
More room for delivery
More blood loss
More difficult to repair
More dyspareunia
Mediolateral episiotomy
Signs of placental separation
Calkin’s sign
Sudden gush of blood from vagina
Lengthening of the cord
Uterus rises to abdomen
Active management of labor
Oxytocin 10U IM
(+) contractions, controlled traction on umbilical cord while other hand places counter suprapubic pressure
Start oxytocin drip
Forceps delivery:
Most common type used
For delivery of fetus with molded head
Simpson forceps
Forceps delivery:
For fetus with a rounded head (common in multipara)
Tucker McLane Forceps
Forceps delivery:
Ideal for rotating head
Head is engaged but is not at the level of perineal floor
Kielland forceps
Forceps delivery:
The double pelvic curve facilitates application to the after-coming head in BREECH presentation
Piper forceps
Forceps delivery:
Leading point of head is at station +2 but not on the pelvic floor
Rotation - >45 degrees
Low Forceps delivery
Forceps delivery:
Leading point of head is above +2 or head is engaged
Fetal and maternal risks are greater
Midforceps delivery
Forceps delivery:
Fetal head or scalp is VISIBLE AT THE INTROITUS
Rotation - <45 degrees
Outlet forceps
Indications for Forceps Delivery
Fetal:
Non-reassuring FHR pattern
Maternal: Prolonged 2nd stage of labor Exhaustion Heart disease Pulmonary disorders
Most common indication for primary cesarean delivery
Dystocia
Breech delivery:
Usually used for small babies
Breech is allowed to deliver spontaneously up to navel
Fetal body held against symphysis pubis
Bracht maneuver
Breech delivery:
2 fingers are placed on malar areas of the fetus
Flexes fetal head in order to permit pelvic passage
Other arm acts as a splint for the nect to prevent hyperextension of neck and exerts downward traction
Mauriceau-Smellie-Viet Maneuver
Breech delivery:
Shoulder’s back pressure
Pull baby posteriorly until chin is under symphysis pubis and will act as a fulcrum to allow delivery
Prague maneuver
Abortion:
Sx: minimal bloody vaginal discharge, no pain or very minimal hypogastric pain
Cervix: closed
Bag of water: Intact
Uterus compatible with AOG
Management: complete bed rest and Pain relief
Threatened Abortion
Abortion:
Sx: minimal to moderate bloody vaginal discharge, minimal hypogastric pain
Cervix: admits tip
Bag of water: Intact
Imminent Abortion
Abortion:
Sx: moderate bloody vaginal discharge, moderate hypogastric pain
Cervix: open
Bag of water: Ruptured
Inevitable Abortion
Abortion:
Sx: profuse bloody vaginal discharge, severe hypogastric pain
Cervix: open WITH PASSAGE OF MEATY TISSUE
Bag of water: Ruptured
Management: elective D&C
Incomplete abortion
Abortion:
Sx: minimal or absent bloody vaginal discharge
Cervix: closed
Uterus: uterus INCOMPATIBLE with AOG
Management: elective D&C
Missed abortion
Abortion:
Three or more consecutive spontaneous abortion
Recurrent Abortion
Painless vaginal bleeding
Cervical dilation (2nd or early 3rd trimester)
Balooning of membranes
Incompetent Cervix
Do cerclage
Most commonly involved site of ectopic pregnancy?
TUBAL
Most commonly involved site of tubal ectopic pregnancy?
Ampulla
Most commonly involved site of ruptured ectopic pregnancy?
Isthmus
Gold standard in diagnosis and subsequent management of ectopic pregnancy
Laparoscopy
Most frequent symptom of ectopic pregnancy
Abdominal pain
Candidates for medical management with Methotrexate in Ectopic pregnancy
Pregnancy <6weeks
Tubal mass less 3.5cm
Absent fetal heart tone
Serum B-hcg <15000mIU/ml
Increase in cardiac output is attributed to which physiologic change?
Decrease systemic vascular resistance and increase heart rate
Principal prostaglandin of endothelium
Regulates BP and platelet function
Decrease in preeclampsia
Prostacyclin (PGI2)
Potent VASOCONSTRICTOR in endothelial and vascular smooth muscle cells
Regulates local vasomotor tone
Stimulates secretion ANP, aldosterone and catecholamine
Endothelin
Potent VASODILATOR released by endothelial cells
Modifies vascular resistance during pregnancy
Nitric Oxide
Normal blood loss in normal singleton spontaneous vaginal delivery?
500ml
Normal blood loss in normal cesarean delivery and twin delivery?
1000ml
Maternal blood expands most rapidly during what trimester?
2nd trimester
Pulmonary anatomic changes during 2nd half pregnancy
transverse diameter of the thoracic cage increases by 2cm
Diaphragm rises about 4cm
Thoracic circumference increases about 6cm
Greater diaphragmatic excursion
Changes in the lung volume during pregnancy
Increased: TV and IC
Decreased: FRC, RV and ERV
Softening of the uterine isthmus
Hegar’s sign
Softening and cyanosis due to increased vascularity and edema of the entire cervix
Goodell’s sign
Increased vascularity affecting vagina and results in violet discoloration
Chadwick’s sign
Melasma gravidarum
“Mask of Pregnancy”
Chloasma
Primarily secreted by adipose tissue
Plays a role in body fat and energy expenditure regulation
Help regulate fetal growth
Deficiency: anovulation and infertility
Abnormally Elevated: preeclampsia and GDM
Leptin
Secreted by the stomach in response to hunger
Has a role in fetal growth and cell proliferation
Ghrelin
Major determinant of maternal insulin resistance after midpregnancy
Secreted by syncitiotrophoblasts
Placental Growth Hormone
Intraabdominal remnants of the umbilical vein
Ligamentum venosum and falciform ligament
Presence in the amniotic fluid is evidence of fetal lung maturity (after 34 weeks)
Pulmonary surfactant
Most active component of pulmonary surfactant
Dipalmitoylphosphatidylcholine
Test for uteroplacental function
Contraction stress test
Test for fetal condition
Non-stress test
Components of Biophysical profile
Non-stress test Fetal breathing Fetal tone Fetal movement Amniotic fluid volume
Onset, nadir and recovery of deceleration are coincident with the beginning, peak and ending of a contraction, respectively
Early deceleration
Onset, nadir and recovery of deceleration are after the beginning, peak and ending of a contraction, respectively
Late deceleration
Most common deceleration pattern
Onset, nadir and recovery of decelerations vary with successive contractions
Variable deceleration
Decrease in fetal heart rate >15bpm, lasting for more than 2mins but less than 10minutes
Prolonged deceleration
Phases of Parturition:
Prelude to parturition
Uterine quiescence, cervical softening
Phase 1 quiescence
Phases of Parturition:
Uterine preparedness for labor, cervical ripening
Phase 2 Activation
Phases of Parturition:
Uterine contraction, cervical dilation
Phase 3 Stimulation
Phases of Parturition:
Uterine involution, cervical repair, breastfeeding
Phase 4 Involution
Shortening of the cervical canal
Causes expulsion of the mucus plug
Cervical effacement
Quantifiable method used to predict labor induction
Bishop Score
What is the direct cause of most maternal deaths involving regional anesthesia?
High spinal blockade
What anesthetic is associated with neurotoxicity and cardiotoxicity at virtually identical serum drug levels?
Bupivacaine
Most common complication encountered during epidural anesthesia
Hypotension