Labor and Delivery Flashcards
Premature rupture of membranes (PROM)
rupture of membranes before the onset of labor
Preterm, premature rupture of membranes (PPROM)
rupture of membranes before 37wks
Prolonged PROM
when PROM occurs more than 18hrs before labor, puts mother and fetus at risk for infection
Rupture of Membranes Dx
SSE showing pooling, +nitrizine and ferning
- Amnisure: rapid test that identifies placental alpha-microglobulin-1 via immunoassay
- Amino dye test: amniocentesis used to inject dilute idigo carmine dye into the amniotic sac to look for leakage from cervix onto tampon
Components of Cervical Exam
Dilation Effacement Fetal Station Cervical Position Consistency of Cervix
- determine if patient is in labor, phase of labor and how labor is progressing
- Bishop score >8= cervix favorable for induced labor
Dilation
how open cervix is at level of internal os (0-10cm)
Effacement
subjective measurement of length of cervix (0-100%)
Fetal Station
relation of fetal head to ischial spines of maternal pelvis (-3 to +3)
Vertex
head down (cephalic)
Breech
buttocks down
Transverse
laying across
Compound presentation
vertex presentation with fetal extremity
Fetal position in vertex presentation
based on relationship of fetal occiput to the maternal pelvis
-determined by palpating sutures and fontanelles
Labor
regular uterine contractions that cause cervical changes in either effacement or dilation
Prodromal labor
false labor
irregular contractions that yield little/no cervical change
Signs of Labor
bloody show, N/V, palpability of contractions, patient discomfort
Induction agents
prostaglandins, oxytocin, mechanical dilation of the cervix, artificial rupture of membranes
Pitocin: synthesized version of the octapeptide oxytocin that is normally released from the posterior pituitary that causes uterine contractions
Indications to Induce Labor
post dates preeclampsia PROM non reassuring fetal testing IUGR
- Bishop score 5 or less may lead to failed induction up to 50% of the time
- cervical ripening with PGE2 gel
- cervidil or misprostol
- mechanical foley
Augmentation of Labor
intervening to increase the already present contractions
indications similar to those for IOL, plus inadequate contraction or prolonged phase of labor
Pitocin or amniotomy
Cervical change
indirect measure of adequacy of contraction
Intrauterine pressure catheter (IUPC)
directly measures chance in pressure during contractions
Electronic fetal monitoring
standard of care
Baseline fetal heart rate
110-160BMP
Tachy >160
Brady <110
Variability: fluctuations in the baseline of FHR
- Absent -amplitude undetected
- Minimal- amplitude range 5BPM or less
- Moderate-amplitude range between 6-25 BPM
- Marked- amplitude range greater than 25BPM
Accelerations
increased in FHR (onset to peak <3secs)
at 32wks: accelerations must be 15x15
Early Decelerations
symmetrical gradual decrease and return of FHR associated with uterine contraction
Late Deceleration
deceleration with nadir occurring after peak of contraction then slowly return to baseline
Variable deceleration
abrupt decrease in FHR
Prolonged deceleration
Lasts 2 minutes or more
FHR interpretation
Category I: normal
Category II: monitor
Category III: abnormal+ must intervene
Fetal Scalp Electrode (FSE)
- small electrode attached directly to fetal scalp
- senses potential differences created by depolarization of fetal heart
- C/I maternal hepatitis/HIV, fetal thrombocytopenia
Intrauterine pressure catheter (IUPC)
- catheter threaded past fetal head into uterine cavity to measure pressure changes during uterine contraction
- measured in Montevideo units in a 10min period
Fetal Scalp pH
fetal blood is obtained from small nick in fetal scalp to directly asses fetal hypoxia and acidemia
non reassuring: <7.20
>7.25 normal
Cardinal Movements of Labor
Engagement Descent Flexion Internal rotation Extension External rotation (restitution)
Engagement
fetal presenting part enters pelvis
Descent
head descends into pelvis
Flexion
allows smallest diameter to present
Internal rotation
rotation from an OT position, usually
to OA
Extension
vertex passes beneath pubic symphysis
External Rotation
once head is delivered
restitution
Labor progression
Assessed by:
1. the progress of cervical effacement
- cervical dilation
- descent of fetal presenting part
Stage 1 of Labor
onset of labor until complete dilation of cervix
nulliparous: 10-12 hours
mutiparious 6-8hrs
Latent phase (stage 1)
from onset of labor to 3-4cm
Active phase (stage 1)
from latent phase to beyond 9cm , slow of cervical change against time increases
1cm/hr nulliparous
1.2cm/hr for multiparous
the 3 Ps
affect transit time during active phase of labor
- powers -strength and frequency of uterine contractions
- passenger- size and position of fetus
- passage/pelvis size and shape (maternal)
cephalopevic disproportion
passenger is too large for pelvis
Stage 2 of labor
complete cervical dilation to delivery of infant
- Prolonged if:
- > 2hrs in nulliparous pt (3hrs with epidural)
- > 1hr in multiparous pt (2hrs with epidural)
*Repetitive early and variable decels are common *Repetitive late decels, bradycardia or loss of variability are non-reassuring
Stage 3 of labor
from delivery of the infant until delivery ofthe placenta completed (5-30 mins)
3 signs of placental separation
- cord lengthening
- gush of blood
- uterine fundal rebound as placenta detaches
Episiotomy
incision made in the perineum to facilitate delivery
Median Episiotomy (midline)
vertical midline incision
from the posterior fourchette into the perineal body
Mediolateral Episiotomy
oblique incision from 5 or 7
o’clock on perineum cut laterally
Operative Vaginal Delivery indications
Prolonged second stage, maternal exhaustion, or the need to hasten delivery
Necessary conditions: full dilation ruptured membranes engaged head at least 2 station knowledge of fetal position no evidence of CPD adequate anesthesia empty bladder
Operative Vaginal Delivery
Types:
Forceps and Vacuum Extraction
Retained Placental
Placenta not delivered within 30 minutes after
infant
- Risk Factors:
- preterm, pre-viable deliveries
- precipitous delivery
- placenta accreta (placenta invaded endometrial stroma
- Manual removal - hand placed intrauterine,
fingers used to shear placenta from surface of
uterus
*Curettage if manual extraction fails
1st degree perineal laceration
superficial, confined to vaginal mucosal layer
2nd degree perineal laceration
into the body of the perineum
3rd degree perineal laceration
into the anal sphincter
4th degree laceration
into the rectum
