L5: Malpresentation & Malposition (OP) Flashcards
Def of Occipito-Posterior Position
Incidence of Occipito-Posterior Position
30-40% during last weeks of pregnancy & 20% at onset of labor
Positions of Occipito-Posterior Position
Types of Occipito-Posterior Position
Etiology of Occipito-Posterior Position
Mechanism of Labor in Occipito-Posterior Position
Deflexion in Occipito-Posterior Position is due to ……
Degrees of deflexion in Occipito-Posterior Position
Descent in Occipito-Posterior Position
Delayed
Engagement in Occipito-Posterior Position
Delayed
- Engaging longitudinal diameter is SOF (10 cm) or OF (11.5 cm). ~ Sob needs full fex
- BPD (9.5 cm) enters pelvis in sacrocotyloid diameter (9.5 cm).
Internal Rotation in Occipito-Posterior Position
Internal Rotation in Occipito-Posterior Position
- Depends on …..
- degree of deflexion
- efficiency of uterine contractions
- pelvic configuration.
Internal Rotation in Occipito-Posterior Position
- Mechanisms
- Normal mechanism long anterior rotation (90%)
- Abnormal mechanisms (failed long anterior rotation (10%)
Internal Rotation in Occipito-Posterior Position
- Normal Mechanism (long anterior Rotation)
Internal Rotation in Occipito-Posterior Position
- Abnormal Mechansim (Short anterior Rotation)
Internal Rotation in Occipito-Posterior Position
- Abnormal mechanism (No Rotation)
Internal Rotation in Occipito-Posterior Position
- Abnormal Mechanism (Posterior Rotation)
Factors Favoring Long anterior Rotation
(Good Omens of OP)
Factors Favoring Long anterior Rotation
(Good Omens of OP)
- Power
- Good efficient uterine contractions
Factors Favoring Long anterior Rotation
(Good Omens of OP)
- Passages
- Roomy pelvis & no cavity or outlet contraction
- Good pelvic floor è proper tonicity (neither rigid nor weak)
Factors Favoring Long anterior Rotation
(Good Omens of OP)
- Passengers
- Well flexed average sized head
- Anterior shoulder isn’t far away from midline.
- No PROM
- Early engagement
Factors Unfavoring Long anterior Rotation
(Bad Omens of OP)
Factors Unfavoring Long anterior Rotation
(Bad Omens of OP)
- Power
Weak uterine contractions
Factors Unfavoring Long anterior Rotation
(Bad Omens of OP)
- Passages
- Abnormal shape of pelvic brim & narrow transverse diameter of outlet
- Relaxed or weak pelvic floor
- Full bladder & rectum, placenta previa & pelvic tumors
Factors Unfavoring Long anterior Rotation
(Bad Omens of OP)
- Passengers
- Persistent marked deflexion of head (commonest cause)
- Anterior shoulder is far away from midline.
- Early ROM
- Delayed engagement
Course of Labor in Occipito-Posterior Position
Read Dx of Occipito-Posterior Position
Managment of Occipito-Posterior Position
- During Pregnancy
- During Labor
Managment of Occipito-Posterior Position
- During Pregnancy
Exaggerated It lateral position hoping for correction into OA (of little value).
Managment of Occipito-Posterior Position
- During Labor
- 1st Stage
- 2nd Stage
- 3rd Stage
Managment of Occipito-Posterior Position
- 1st Stage
As Normal Labor
Managment of Occipito-Posterior Position
- 2nd Stage
- Wait for 2 hours + observe mother & fetus + give oxytocin drip to correct inertia (if there are no contraindications).
- Then According to position
Managment of Occipito-Posterior Position
- Long Anterior Rotation
The rest of management is as OA.
Managment of Occipito-Posterior Position
- Posterior Rotation (Face to Pubis)
- Spontaneous vaginal delivery + deep episiotomy.
- Outlet forceps extraction + deep episiotomy.
Managment of Occipito-Posterior Position
- DTA
- Persistent oblique OP
Head can’t be delivered spontaneously & they can be dealt e by one of the Vip following methods depending on fetal size, pelvic configuration, general condition of mother & fetus & skills of obstetrician:
- Manual rotation& forceps extraction
- Forceps Rotation & Extraction
- Vacuum Extraction & Deep Episiotomy
- CS
- Craniotomy
Managment of DTA & Persistent oblique OP
- Manual Rotation & Forceps Extraction
Managment of DTA & Persistent oblique OP
- Forceps Rotation & Extraction
Managment of DTA & Persistent oblique OP
- Vaccum Extraction & deep Episiotomy
Managment of DTA & Persistent oblique OP
- CS
Managment of DTA & Persistent oblique OP
- Craniotomy
If fetus is dead (not done now).
Managment of Occipito-Posterior Position
- 3rd Stage
As Normal Labor
Complications of Occipito-Posterior Position
Complications of Occipito-Posterior Position
- Prolonged Labor
Due to long anterior rotation & abnormal uterine action.
Complications of Occipito-Posterior Position
- PROM
Due to ovoid plane of engagement of fetal head.
Complications of Occipito-Posterior Position
- Pernineal & Vaginal Lacerations & tears
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