Parturition, Labor and Delivery Flashcards
What are four phases of parturition?
Phase 1: uterine quiescence, cervical softening
Phase 2: uterine activation, cervical ripening
Phase 3: uterine contraction, cervical dilatation
Phase 4: uterine involution, cervical remodelling
What are the functions of the cervix during pregnancy?
Barrier function: protect the reproductive tract from infection
Maintain cervical competence despite increasing gravitational forces
Extracellular matrix changes for tissue compliance
What myometrial changes occur during the 2nd phase of parturition
Expression of contractile-associated proteins
Lower uterine segment formation
What are the therapies to prevent and to promote cervical ripening?
Prevent: none
Promote: PGE2, and PGF2 alpha
What are the causes of pain of the uterine smooth muscle during labor?
Hypoxia of the contracted myometrium
Compression of the nerve ganglia
Cervical stretching
Peritonial stretching
Differentiate the upper uterine segment from the lower uterine segment during the first stage of labor?
Upper segment: progressively thickens, does not fully relax after contraction
Lower segment: softer, distended, more passive; expanded, thinned-out tube
What causes cervical dilatation?
Centrifugal pull on the cervix
Hydrostatic action of the amniotic sac
What is the most important pelvic floor sturcture for fetal descent?
Levator ani muscle, composed of
Purorectalis
Pubovisceral
Iliococcygeus
What happens during the 3rd stage of labor?
Placental separation: uterine contraction and separation of decidua spongiosa
Placental expulsion: Schultz mechanism and Duncan mechanism
Criteria for labor:
Uterine contractions - 1 in 10 mins
Cervical effacement 70-80%
Cervical dilatation > 3cm
What is Bishop score? What are its components
Predict labor induction outcome
Score of 9: high likelihood of success
Score of = 4: unfavorable
IE / Bishop score Dilataion Effacement Membranes Position Station
What are the indictaions for induction of labor?
5 maternal factors: Gestational hypertension Comorbids Logistic factors Eclampsia, preeclampsia PROM
4 fetal factors: Demise Postterm Infection Compromise
What are the contraindications of labor induction
Maternal factors (7) Carcinoma Herpes Medical conditions Placenta previa Surgeries in the past Physician’s convenience CPD
Fetal factors (2)
Malpresentation
Cord presentation
What are the methods of labor induction?
Membrane stripping
Oxytocin
Amniotomy
What are the signs of hyperstimulation?
Increased contraction frequency
Increased duration (>120s)
Abnormal fetal heart rate
