Abnormal labour (dystocia)

4 abnormalities that are part of dystocia

• abnormalities of expulsive forces → uterine dysfxn

• abnormalities presentation/position/dev of fetus

• abnormalities maternal pelvis (pelvic contraction)

• abnormalities maternal soft tissues

dystocia - active-phase abnormalities

protraction disorder (slow rate cervical dilatation or descent, <1.2cm/hr)

arrest disorder (complete cessation of dilatation or descent, 2hr w/o cervical change, 1hr w/o descent)

what describes unsuccessful labour

cephalopelvic disproportion (diff bw fetal head and maternal pelvis size)

failure to progress (loss cervical dilatation or fetal descent)

______ is the most frequent current indication for primary cesarean section

dystocia

cervix should be dilated to _______ before diagnosing dystocia

4cm or more

ttt uterine dsyfxn as part of dystocia

oxytocin

2 types of uterine dysfxn - as part of dystocia

• hypotonic (synchronous), absence basal hypertonus and regular gradient contractions

• hypertonic (incordinate), elevated basal tone or pressure gradient inaccurate

second stage labour disorders - how long is too long

nulliparas - 3hr if regional analgesia, 2h if not

multiparas - 2hr if regional analgesia, 1h if not

labour factors causing uterine dysfxn (dystocia)

• epidural analgesia

• chorioamnionitis

• birthing position

precipitous labour

extremely rapid labour and delivery (from low resistance in soft tissue, strong contractions)

<3h

consequences precipitious labour

hypotonic uterus → hemorrhage from placental implantation site

newborn falls, low fetal O2

what is considered a ‘contracted’ anteropost diameter of pelvis

pelvic inlet <10cm or greatest transverse diameter <12cm

midpelvis and interischial tuberous diameter <8cm

caldwell-moloy classification

abnormal labour - 4 parent pelvic types (gynecoid, anthropoid, android, playtpelloid)

estimation of pelvic capacity

xray pelvimetry, mri

digital exam of anteropost diameter of inlet <90dg is narrow

face presentation (head hyperextension, chin presenting) of fetus in dystocia - etiologies

preterm, enlarged neck or coils of cord around neck,

fetal malformations and hydramnios - risk factors for face or brow

management face presentation during labour

if pelvic contraction - c section

brow presentation fetus (dystocia)

fetal head midway bw full flexion and extension

only frontal sutures, ant fontanels, eyes palpable on vaginal exam

transverse lie (dystocia)

shoulder positioned over pelvic inlet, head occupies one iliac fossa, breech occupies the other

dg - abdomen wide, uterine fundus extends sligtly above umbilicus, can feel ribs of baby during vaginal exam

etiologies transverse lie

abd wall relaxation from high parity

preterm

placenta previa

management transverse lie

c section (risk rupture), vertical incision

compound presentation

extremity goes down alongside the presenting part

both present at same time in pelvis

from preterm labour

how to deliver if persistent occiput post position

• delivery w/ spontaneous ant rotation of occiput

• forceps w/ occiput post

• manual rotation to occiput ant → spontaneous or forceps

• forceps rotation to occiput ant and delivery

etiology and risk factors shoulder dystocia

macrosomia

obesity, multiparity, dm

if the head-to-body delivery time exceeds 60 seconds, it should be defined as

shoulder dystocia

maternal vs fetal consequences of shoulder dystocia

maternal - postpartum hemorrhage, vaginal/cervical lacerations

fetal - mortality, brachial plexus injury, clavicular/humeral fx

maneuvers for shoulder dystocias

woods - by gradually rotating the posterior shoulder 180 degrees in a corkscrew fashion, the impacted anterior shoulder could be released

mcroberts - 2 assistants hold and flex maternal thigh against abdomen

maternal complications w/ dystocia

intrapartum chorioamnionitis and postpartum pelvic infection

postpartum hemorrhage

uterine rupture

fistulas

fetal complications w/ dystocia

perventricular/intraventricular hemorrhage, brain damage, neonatal encephalopathy

meconium aspiration sd