Labour & Delivery Flashcards
What is the difference between True Labour and Braxton Hicks contractions?
True = regular, painful, increasing intensity contractions; cervix dilates/effaces, progression of fetal station False = irregular, not changing intensity/freq, no cervical changes; throughout pregnancy
Labour ctx: 4:1:1 rule - Ctx every 4 minutes, lasting 1 minute, for at least 1 hour
Describe the stages of labou
Stage 1 latent: <4cm
Stage 1 active: 4-10 cm
2nd stage: 10 cm-delivery of baby
3rd stage: delivery baby –> delivery placenta
4th stage: delivery placenta –> 1-4 hr postpartum
Is posterior or anterior cervical positioning indicative of further in labour?
Moves posterior –> anterior
orientation of the long axis of the fetus with respect to the long axis of the uterus (longitudinal,
transverse, and oblique)
fetal lie
fetal presentation =
Which is the only normal one?
fetal body part closest to the birth canal
Normal = vertex/occiput/cephalic
Fetal position
Position of presenting part relative to maternal pelvis (e.g. OA (“normal”), OP, OT)
2 examples of abnormal fetal attitude
Brow presentation
Face presentation
Define fetal station
Position of presenting bony part relative to ischial spines (determined via vaginal exam)
-5 to -1 cm above spines
+1 to +5 below spines
What is synclitism?
Alignment of the sagittal suture relative to axis of birth canal (A or P asynclitism may impact descent)
Fetal position is described by ___ for cephalic presentation, ___ for breech presentation, ___ for face presentation
Occiput
Sacrum
Mentum
4 key HPI questions during labour triage
1) Contraction - since when, how freq, how long, how painful
2) Bleeding - wsince when, how much, colour, pain, last U/S, any trauma/intercourse?
3) Fluid (ROM) - when, how much, colour
4) FM: as much as usual? when last?
Describe contractions during the active first stage of labour?
Painful, regular, q2-3 min, 45-60 s each
Mother feels a desire to bear down/push with each contraction during which stage of labour?
Second stage
Third stage of labour can last up to __ before intervention is indicated?
30 min
Routine ___ administration in the 3rd stage of labour (either give with delivery of baby or after placenta delivered) can reduce the risk of PPH by >40%
Oxytocin
The __ and ___ stages of labour are most dangerous to the mother
3rd-4th (PPH)
What is fetal engagement and when does it happen?
The widest diameter of the presenting part (with a well-flexed head, where the largest transverse diameter of the fetal occiput is the biparietal diameter) enters the maternal pelvis to a level below the plane of the pelvic inlet. On the pelvic examination, the presenting part is at 0 station, or at the level of the maternal ischial spines.
In first pregnancy often happens weeks before birth
Non-pharmacological pain relief techniques for labour (3 categories + examples)
1) Reduce painful stimuli (position change, maternal movement)
2) Activate peripheral sensory receptors (superficial heat/cold, water immersion, TENs, massage, aromatherapy)
3) Enhance descending inhibitory pathways (distraction, hypnosis, music, biofeedback)
Pharmacological pain relief methods
Nitrous oxide narcotics Pudendal nerve block Local anesthetic Regional anesthetic (EPIDURAL, spinal)
Prevalence, prognosis, and etiology of Meconium Aspiration Syndrome
In about 10% of pregnancies overall, the fetus discharges meconium (its bowel contents) into the amniotic fluid during labour. In about 10% of cases where meconium is passed, the fetus gasps, inhaling the sticky meconium into the upper respiratory tract. After birth, the meconium blocks the air passages in the lungs, impairing gas exchange–meconium aspiration syndrome (MAS). Up to 20% of infants suffering from MAS die and recently published studies have shown a long-term effect of MAS in causing cough and wheeze
2 delivery characteristics that increase the likelihood of meconium aspiration syndrome?
C-section
Postterm
Presentation of meconium aspiration syndrome
GREEN AMNIOTIC FLUID
Low APGAR, tachypnea, hypoxia, WOB
APGAR stands for what?
Score below what may need intervention?
Activity (muscle tone) Pulse Grimace (reflex irritability) Appearance (skin colour) Respiration (<7 may need intervention)
Is continuous fetal monitoring always better?
No, leads to increased intervention
Do it if you have abnormal or induced labour, meconium present, multiple gestation, fetal concerns
What can be used to resolve interpretation of abnormal/atypical FHR and CTG (contraction monitoring) patterns?
Fetal scalp sampling
Is variability in FHR bad?
No! Physiological variability is normal and absence can be bad
What FHR decelerations are normal?
Early decelerations: nadir coincides with peak of contraction then quickly returns to baseline
Normal vagal response to head compression
What are variable FHR decelerations? Are they good or bad?
Variable in shape/onsent/duration
Can be due to cord compression or forceful pushing in 2nd stage
Complicated if return to baseline is slow/incomplete, too bradycardic (possible fetal acidemia)
What are late decelerations?
Onset + nadir + recovery after peak of contraction, slow return to baseline
Indicates fetal hypoxia/acidemia, usually a sign of uteroplacental insufficiency (ominous)
Normal FHR and variability
110-160
6-25 bpm
Normal FHR accelerations
Spontaneous or during scalp stimulatino
What is measured in a fetal scalp sample?
pH & lactate (looking for acidosis –> if present, deliver!!)
Maternal cervix needs to be __ for induced labour. If not, what can you use?
“Ripe” (short, thin, soft, anterior, open os)
Can use intravaginal prostaglandins (e.g. misoprostol in clinical trials), foley catheter for mechanical dilation
What score determine likelihood of success for induced labour?
Bishop score
cervical position/consistency/effacement/dilatation, fetal station
What is the most common reason for inducing labour?
> 41 weeks
Maternal indications for induced labour? (4+)
MDM Gestational HTN >37 wk Preeclampsia Mom >40 Other maternal diseases
Maternal-fetal indications for induced labour (3)
Isoimmunization
PROM
Chorioamnionitis
___ is the artificial initiation of labour
____ promotes contractions when
spontaneous contractions are inadequate
Induction
Augmentation
Fetal indications for induced labour
Fetal jeopardy (but not fetal distress or malpresentation)
Macrosomia
Demise, IUGR, oligo-polyhydramnios
Twins, previous stillbirth
2 serious complications of induced labour
Uterine hyperstimulation –> fetal compromise or uterine rupture
Uterine muscle fatigue –> atony (failure to contract) + PPH
Describe uterine atony
Uterine atony refers to the corpus uteri myometrial cells inadequate contraction in response to endogenous oxytocin that is released in the course of delivery. It leads to postpartum hemorrhage as delivery of the placenta leaves disrupted spiral arteries which are uniquely void of musculature and dependent on contractions to mechanically squeeze them into a hemostatic state. Uterine atony is a principal cause of postpartum hemorrhage, an obstetric emergency.
2 components of inducing labour after cervical ripening
1) Amniotomy
2) Oxytoxin
(Not ALWAYS both)
What med is used to augment labour when spontaneous contraction inadequate and cervical dilation or fetal descent fails?
Oxytocin
What is dystocia?
Failure of expected patterns of descent/dilation to occur in expected timeframe
4 Ps of dystocia
Power: weak contractions, inadequate pushing
Passenger: fetal position/attitude, size
Passage: pelvic structure (CPD), maternal soft tissue factors (full bladder/rectum, vaginal septum, tumors)
Psyche: stress hormone
What is CPD?
Cephalopelvic disproportin
Fetus head can’t fit through pelvis –> failure to progress (need C/S)
What is the most common etiology of dystocia?
POWER
Management of dystocia
Rule out CPD
Then IV oxytocin augmentation + amniotomy
Define Shoulder dystocia
Fetal anterior shoulder impacted above pubic symphysis after head delivered –> LIFE-THREATENING EMERGENCY
____ will resolve 90% of cases of shoulder dystocia.
McRoberts maneuver (flex legs onto abdomen) + suprapubic pressure on fetal anterior shoulder
Umbilical cord prolapse =
Cord moves below (or adjacent to) presenting part –> cord compression
Treatment of umbilical cord prolapse
Emergency C/S if delivery not imminent
O2 to mother, monitor FHR, alleviate pressure on chord via pelvic exam until C/S
Define grand multiparity
5+ births at 20+ weeks
Associated with increased maternal risks
Common causes of uterine rupture
Previous uterine scar (40%) (usually <1% incidence but up to 12% with classical C/S incision, even before labour) Oxytocin hypertimulation Grand multiparity (5+ deliveries)
If uncontrollable hemorrhage from uterine rupture –>
Hysterectomy
HELLP Syndrome
A complication of pregnancy and form of preeclampsia that most commonly occurs > 27 weeks’ gestation. Characterized by hemolysis (H), elevated liver (EL) enzymes, and low platelet (LP) count
Amniotic fluid embolus
Amniotic fluid debris in maternal circulation –> anaphylactoid immunological response –> RD, CV collapse, coagulopathy
Up to 30% maternal mortality
What is the controversy around epistiotomy?
Current evidence suggests letting perineum TEAR and then repairing as needed is better
Risk factor for shoulder dystocia
Maternal DM/GDM
Fetal prolonged gestation/macrosomia
Define chorioamnionitis + etiology
Infection of chorion/amnion/amniotic fluid
Ascending infection from vagina
Clinical features + treatment of chorioamnionitis
Fever, tachycardia, uterine tenderness, foul discarge
IV antibiotics
Meconium :
More common in ___ pregnancies
Present in up to ___ of all labours
Is it associated with poor outcome?
Postdate
25%, usually NOT associated with poor outcome but ALWAYS abnormal if preterm fetus (and concern if fluid changes from clear –> meconium stained)
Increasing meconium during labour may be sign of ___
Fetal distress
What is the most common cause of postpartum hemorrhage?
Uterine atony (70-80%)
Define puerperium
6 weeks after delivery when physiological/anatomic changes are reversed
Define postpartum hemorrhage
> 500 mL blood loss vaginal delivery
1000 mL blood loss C/S
Primary = within 1st 24 hours
Secondary/Late = within 12 weeks
DDx of Early PPH (4 Ts)
Tone (uterine atony)
Tissue
Trauma
Thrombin (coagulopathy, e.g. vWD)
Prevention of uterine atony (3)
Oxytocin administration
Uterine massage
Umbilical cord traction
Medical treatments for PPH
Oxytoxin Ergotamine Carboprost (PGF analog) Misoprostol Tranexamic acid (antifibrinolytic)
Local treatments for PPH
Bimanual massage through abdomen Uterine packing (mesh w/ AB treatment) Bakri Balloon for tamponade while correcting coagulopathy or prepping for OR
Surgical therapies for intractable PPH
D&C
Embolization of uterine artery or internal iliac artery
Laparotomy with artery ligation
Hysterectomy = last resort
Formation of scar tissue in uterus (usually after surgery) =
Asherman’s syndrome
Retained placenta =
not delivered within 30 min after fetus delivered
Define placental previa and vasa previa
Placental previa = placenta blocking cervix
Vasa previa = embranes that contain fetal blood vessels connecting the umbilical cord and placenta overlie or are within 2 cm of the internal os
When is screening for gestational diabetes recommended?
24-28 weeks
What is the preferred screening for GDM?
The preferred approach is an initial 50 g glucose challenge test, followed, if abnormal, with a 75 g oral glucose tolerance test. A diagnosis of GDM is made if one plasma glucose value is abnormal (i.e. fasting ≥5.3 mmol/L, 1 hour ≥10.6 mmol/L, 2 hours ≥9.0 mmol/L)
** if high risk of undiagnosed type 2, screening EARLY (<20 weeks) via HbA1c
DIC can be caused by obstetric complications via release of ___
Procoagulants (—> tons of clots formed but then also increased bleeding due to consumptions of platelets/clotting factors)
placenta grows too deeply into the uterine wall. Typically, the placenta detaches from the uterine wall after childbirth. With placenta accreta, part or all of the placenta remains attached. This can cause severe blood loss after delivery.
^what is this and what is the general approach?
Placenta accreta
C-section important. Can try to remove placenta but may need hysterectomy
Bloody show
A blood-tinged mucous plug may be discharged when the cervix shortens and dilates.
Normal birth weight
2.5-4.5 kg
Fundus above umbilicus during PPH =
uterus hasn’t contracted
This meta-analysis showed that ___ was as effective and safe as oxytocin for prevention of postpartum hemorrhage in women undergoing vaginal delivery, and the choice of carbetocin for routine prophylaxis will depend on cost-effectiveness.
Carbetocin (long-acting oxytocin analogue)
Centre-dependent practices
What are the 4 degrees of vaginal tears in childbirth?
1st = perineum skin only, may not require stitches
2nd = skin/muscle of perineum, may extend deep into vagina; stitches done in delivery room
3rd = extends into anal sphincter. May need OR repair
4th - all the way through anal sphincter + rectal mucosa
