Normal L&D Flashcards
When does beta-HCG peak?
10 weeks gestation
When can a pregnancy first be detected by ultrasound? What do you see?
TRANSVAGINAL- 5 weeks. Gestational sac but no heart until 6 weeks.
Beta-HCG level for TV U/S detection? Abdominal
1500 to 2000
Abdominal needs >6500
First trimester
up to 12 wks
Second trimester
12 wks to 24 wks
Third trimester
24 wks (or 28) to delivery
PreVIABLE delivery?
Before 24 wks
What EXACTLY does parity mean?
A pregnancy that led to a birth at or beyond 20 wks OR of an infant weighing more than 500g
Given birth to a set of twins?
G1P1 (it is considered ONE pregnancy)
The order of #s in GP….
pregnancies/#births at TERM/#births at PREterm/abortuses/living kids
What changes occur in the cardiovascular system during pregnancy?
1) CO inc by 30-50% (max at 20-24 wks then maintained)
2) Systemic vascular resistance decreases
3) BP drops and nadirs at 24 weeks then rises
Changes in pulm system during pregnancy?
1) Tidal volume inc
2) Respiratory rate UNCHANGED…therefore the combo increases MINUTE VENTILATION which inc O2 levels overall
3) Dyspnea of pregnancy
Changes in GI system in pregnancy?
Morning sickness…hyperemesis gravidarum
Prolonged gastric emptying time so GERD sx
Large bowel has dec motility so constipation
Hyperemesis gravidarum?
Severe morning sickness= WEIGHT LOSS & KETOSIS.
Renal system in pregnancy?
1) Kidneys get bigger
2) Ureters dilate
3) GFR inc by 50% early in pregnancy
4) Therefore BUN and creatinine dec
5) RAAS system inc (but sodium levels DON’T inc bc of the concomitant inc in GFR)
Hematologic changes in pregnancy?
1) Plasma volume increases more than hematocrit (RBCs) so there’s a DILUTIONAL ANEMIA
2) WBC count inc (range of 6-16 million). During stress of labor may rise to 20 million.
3) Platelets drop beta 100-150million/mL. (Greater drop INVESTIGATE IMMEDIATELY)
4) Hypercoagulability due to inc in fibrinogen, factors VII-X; clotting and bleeding TIMES don’t change
Endocrine changes in pregnancy?
1) Hyperestrogenic state
2) Alpha subunit of beta-HCG mimics LH, FSH, and TSH; peak at 10-12 wks
3) hPL inc (produced by placenta). Induces lipolysis with a concomitant inc in free fatty acids; also is insulin antagonist
4) Prolactin LEVELS inc but it doesn’t do anything until after birth of baby
5) Estrogen stims TBG, so there’s an inc in TOTAL T3 and T4 but FREE T3/T4 remain constant.
Calorie intake req during preg?
300kcal/day for preg; 500 kcal/day for breastfeeding
Weight gains
Underweight= 28-40lbs Normal= 20-30lbs Overweight= 15-25lbs
Folate req
0.4-0.8mg/day (Previous NTD or inc risk is 4mg/day)
Urinalysis in pregnancy looks for what?
Protein- preeclampsia
Glucose- diabetes
Leukocyte esterase- UTI
What are pregnant patients asked at EACH visit? What gets added after 20 weeks?
1) Vaginal bleeding
2) Vaginal discharge or leaking of fluid
3) Urinary symptoms
THEN
1) Contractions
2) Fetal movement
Components of the triple screen? Quad screen?
MSAFP (inc in NTD, dec in Down syndrome)
B-HCG
Estriol
Inhibin-A in quad screen
Second trimester visits?
- MSAFP between 15-18 wks
- Screening u/s between 18-20 wks
- Triple screen/quad screen
- Fetal heart is first heard
Third trimester visits? How often?
- Rhogam at 28 wks
- Leopold maneuvers 32-34 and beyond
- Breech are offered external cephalic version of fetus at 37-38 wks
- Vigorous exam of the cervix (“sweeping” the membranes) to determine probability of progressing post term or needing induction
- Vaginal cultures repeated in high risk ladies
- HSV latent: antiviral prophylaxis at 36 wks
- HSV active: plan c-section
- GBS screen beta 35-37 wks
Every 2-3 wks from 28-36 wks
Every week after 36 wks
WHEN IS “TERM”?
After 37 weeks
Lab tests during third trimester?
Hct (Hemoglobin below 11mg/dL start on iron supplements). Hct gets close to its nadir in 3rd trimester.
RPR/VDRL
GLT (glucose loading test)
PRETERM LABOR
LABOR THAT BEGINS BEFORE 37 WKS
Postterm pregnancy
After 42 weeks
GTT specifics
1) Fasting serum glucose measurement
2) 100g oral glucose loading dose
3) Measure serum glucose at 1, 2, 3 hours after oral dose
Thresholds for gestational diabetes diagnosis
Fasting gluc > 95
1 hour 180
2 hrs 155
3 hours 140
Routine u/s screening when?
18-20wks
BPP (biophysical profiles) look at what?
-Amniotic fluid volume
-Fetal tone
-Fetal activity
-Fetal breathing movements
-NST which tests FHR with fetal movement
Score of 2 each with a max of 10
8-10 is reassuring
Oxytocin challenge test (OCT) or contraction stress test (CST)
Why do you do them??
Get at least 3 contractions in 10 min
Concomitant FHR monitoring (reactivity criteria are the same as for NST)
If NST is nonreactive or FHR shows decelerations, or if BPP is non reassuring
NST is considered reactive if…
Two accelerations of FHR in 20 min that are at least 15 beats above baseline HR and last for at least 15 sec.
When would you do an NST in antenatal testing?
What if it’s nonreactive?
32-34 wks in high-risk pregnancies
40-41 wks in undelivered
Assess the fetus via ultrasound
What is PUBS used for?
percutaneous umbilical blood sampling
Fetal hematocrit level detection…
Like in Rh isoimmunization, fetal anemia, hydrops, fetal transfusion, fetal platelet count in alloimmune thrombocytopenia, karyotype analysis
Testing for fetal lung maturity?
Type II pneumocytes start secreting surfactant (they’ve used phospholipids to make it).
Lecithin/spingomyelin ratio increases with maturity.
Lecithin= lung maturity
Fetal lie
Longitudinal or transverse
Fetal presentation
Breech or vertex ( which can be cephalic if face first or not truly vertex)
Rupture of membranes suspected when?
Gush or leaking of fluid from vagina
This is sometimes hard to differentiate from stress incontinuence and small leaks of amniotic fluid
How do we diagnose ROM?
POOL, NITRAZINE (turns blue), FERN tests.
Vag is acidic, amniotic fluid is alkaline.
What can cause a false positive nitrazine test?
Fluid from cervix
What can you do if ROM tests are equivocal?
U/S to see fluid level. Oligohydramnios that was previously normal = ROM.
What if you REALLY need to know if it’s ROM (eg. PPROM when you need antibiotic prophylaxis)?
1) AMNISURE- rapid. Alpha-microglobulin-1 immunoassay.
2) Amniocentesis to inject dilute indigo carmine dye into the amniotic sac.
How do you obtain the Bishop score?
Cervical exam
What is in the Bishop score?
- Dilation
- Effacement
- Fetal station
- Cervical position
- Consistency of the cervix
With what Bishop score is a cervix favorable for spontaneous and induced labor?
8 or higher
What is station? Where is +3?
Relation of the FETAL HEAD to the ISCHIAL SPINES.
+3 is at the introitus
Common indications for induction?
Postterm pregnancy Preeclampsia Diabetes Nonreassuring fetal testing IUGR
Contraindications of using prostaglandins? Maternal? Obstetric?
Maternal:
- Asthma
- Glaucoma
Obstetric:
- Prior c/s
- Nonreassuring fetal testing
Dilation options?
Prostaglandins
Oxytotic agents
Mechanical dilation of cervix (eg. with Foley bulb)
Artificial ROM (amniotomy)
General rules about induction?
If it’s not an urgent issue, you need to wait for a favorable Bishop score (>5).
What is usually given first for induction
Pitocin
Continuous IV because it’s rapidly metabolized
Key to check during amniotomy?
For umbilical cord prolapse
What inducing methods are also used for augmentation?
Pitocin and AROM
When would you augment?
Prolonged phase of labor
Inadequate contractions
FHR baseline above 160 is worrisome for…
Infection
Hypoxia
Anemia
How long is too long for a deceleration?
> 2 min
Fetal heart rate variability?
Absent: 25 bpm
Formally reactive FHR?
At least 2 accelerations of at least 15 bpm that last for 15 sec within 20 min.
Early decels? Cause?
Begin and end with contractions (relatively)
Fetal head compression which increases vagal tone
Variable decels? Cause?
Happen anytime and drop more suddenly than early or lates.
Umbilical cord compression
Late decels? Cause?
When late decels occur with decreased variability what is most likely cause?
Start at PEAK of a contraction and slowly return to baseline after the contraction finished
UTEROPLACENTAL INSUFFICIENCY
Fetal acidosis strongly suspected when late decels happen with decreased variability
Contraindications to using a fetal scalp electrode to track repetitive decels?
Maternal hepatitis or HIV
Fetal thrombocytopenia
Category I FHR?
Normal: normal baseline, moderate variability, no variable or late decels
Category II FHR?
Indeterminate
Category III FHR?
Abnormal!
Absent variability
Recurrent late or variable decals
Bradycardia
SINUSOIDAL PATTERN
What is sinusoidal pattern?
Fetal anemia
Montevideo units?
Intrauterine pressure’s variation average FROM baseline x # of contractions in a 10 min period
If fetal heart rate tracing is non reassuring, what can you do to check for fetal hypoxia or acidemia?
Fetal scalp ph- obtained by making a nick in the scalp and drawing up some blood.
Reassuring is pH greater than 7.25. Below 7.2 is non reassuring.
What could falsely elevate results of fetal scalp pH reading?
Mixing the blood with BASIC amniotic fluid would give it a falsely low therefore non reassuring reading.
Stages 1 of labor?
Onset until dilation/effacement of cervix are complete.
Latent and active phases
How long does stage 1 last in nulliparous patient? Multiparous?
10-12 hours (6-20 is considered normal)
6-8 hours multiparous (2-12 is considered normal)
Latent phase of stage 1
Onset until 3-4 cm dilation. SLOW cervical change. Mostly effacement rather than dilation.
Active phase of stage 1
After latent up until 9 cm of dilation
The slope of cervical change against time increases.
How much dilation in expected per hour in active phase for a nulliparous patient? Multiparous?
- 0 for nulliparous
1. 2 for multiparous
What 3 factors affect transit time for active labor?
Powers, passenger, pelvis
What if “passenger” is too large for “pelvis”?
Cephalopelvic disproportion
What happens if the cervical change is less than 1.0cm per hour?
You need to assess the three P’s to determine whether a vaginal delivery can be expected
Active phase arrest?
No change in cervical dilation OR station for TWO HOURS even though there are ADEQUATE MONTEVIDEO UNITS in the active phase of labor.
What POA for active phase arrest?
C-section OR watch and wait
Stage 2 of labor?
From complete cervix dilation until delivery of the infant
What is considered “prolonged stage 2” in nulliparous? Multiparous?
Nulliparous- more than 2 hours; 3 hours if they had epidural
Multiparous- more than 1 hour without epidural; more than 2 hours with epidural
Monitoring during active second stage of labor. What’s normal and what’s worrisome?
Normal- repetitive early and variable decels
Worrisome- Repetitive late decels, bradycardias, loss of variability
What to do for worrisome tracings during second stage?
Give face mask O2, turn patient on her left side, discontinue oxytocin immediately if it’s being used
What do you do if a prolonged deceleration happens due to hypertonus or tachysystole? What if this intervention doesn’t help?
Give terbutaline to relax the uterus
If that doesn’t help, assess fetal station and position to see if vaginal delivery is favorable. If fetal station is above 0 or position is unknown, C-SECTION.
What is hypertonus?
Single contraction lasting more than 2 mins
What is tachysystole?
Greater than 5 contractions in 10 min
Conditions for the safe use of vacuum extractor and foreps for delivery?
Full dilation of the cervix, ruptured membranes, engaged head and at least +2 station, no evidence of CPD, anesthesia adequate, empty bladder, EXPERIENCED OPERATOR #1
Risks of forceps and vacuum?
Fetal complications:
Forceps- facial nerve palsies
Vacuums- cephalohematomas
Maternal complications:
Forceps- 3rd and 4th degree perineal lacerations
Stage 3 of labor?
After baby delivered until delivery of placenta
Time frame for placental separation?
Usually 5-10 minutes but up to 30 is normal limit.
The 3 signs of placental separation?
1) Cord lengthening
2) Gush of blood
3) Uterine fundus rises
THEN you can start attempting to deliver it
What can happen if you put too much traction while trying to deliver the cord? How can the doctor avoid this?
Uterine inversion
Doctor needs to apply suprapubic pressure to keep the uterus from inverting or prolapsing
Common causes of retained placenta? What do you do? If EVEN this fails?
This means more than 30 mins to deliver it.
- Preterm, ESPECIALLY previable
- Sign of placenta accreta
DELIVER W/ MANUAL EXTRACTION
If it STILL doesn’t come out, do curettage
LACERATIONS 1st-4th?
1st- Mucosa or skin
2nd- Extend into perineal body
3rd- Into or completely through the anal sphincter
4th- Anal muscosa has been entered
4th degree “buttonhole”- through rectal mucosa into vagina but with anal sphincter still intact
MC reason for c-section? Others?
1) Failure to progress in labor. Eg. 3 P’s OR a previous c-section
- Breech presentation or transverse lie
- Placenta previa
- Placental abruption
- Fetal intolerance of labor
- Nonreassuring fetal status
- Cord prolapse
- Prolonged second stage
- Failed operative vaginal delivery
- ACTIVE HERPES LESIONS
VBAC possible if what conditions? What is greatest risk during TOLAC?
Low transverse or low vertical incision for the prior hysterotomy
Greatest risk is RUPTURE OF PRIOR SCAR
0.5-1% of the time.
What increases the risk for uterine rupture during TOLAC?
- Multiple prior cesarean deliveries
- Induction of labor
Signs of rupture?
- Abdominal pain
- FHR decelerations or bradycardia
- Sudden pressure decrease on IUPC
- Mom feels a pop
Why should sedating analgesics not be used near expected time of delivery?
It can cross the placenta and may result in a depressed infant
Epidural placement? Advantages?
In L3-L4 interspace ONCE ACTIVE LABOR STARTS!!
Initial bolus then continuous infusion.
Labor is slower but it offers better control during crowning.
When is spinal anesthesia given over epidural?
Given in one time dose directly into spinal canal so it’s MORE RAPID.
Better for c-section.
Complications of spinal or epidural anesthesia?
Maternal hypotension due to decreased systemic vascular resistance–> dec placental perfusion and fetal bradycardia
SERIOUS: material respiratory depression
When would you use general anesthesia?
Rarely
Emergency c-section
Clinically adequate contractions?
Every 2-3 minutes lasting at least 40-60 sec.
OR
Montevideo units >200
Engagement
Relationship of the WIDEST DIAMETER of the fetal presenting part and its location relative to the pelvic inlet
Low birth weight infant?
Less than 2500 g
Risks of prematurity?
- RDS or hyaline membrane disease
- Intraventricular hemorrhage
- Sepsis
- Necrotizing enterocolitis
RISK FACTORS FOR PRETERM LABOR
- PROM
- Chorioamnionitis
- Multiple gestations
- Uterine anomalies like bicornuate uterus
- Previous preterm
- Maternal pre pregnancy weight less than 50 kg
- Placental abruption
Maternal:
- Preeclampsia
- Infections
- Intra-abdominal disease or surgery
- Low SES
Tocolytics- why give? Why does HYDRATION decrease contractions?
GOAL IS TO DECREASE INTRACELLULAR CALCIUM WHICH DECREASES MYOMETRIAL CONTRACTILITY
When you need to decrease or halt the cervical change that results form contractions
Hydration decreases ADH release (so you can pee out that extra water). ADH and oxytocin have similar structures, so dec the ADH can also dec the oxytocin.
If no response, give tocolytics.
Beta-mimetic tocolytics? Mech? Side effects?
TOCOLYTIC
Ritodrine (cont IV), terbutaline (subq).
Increases conversion of ATP to cAMP which sequesters FREE calcium in sarcoplasmic reticulum (HIDES IT THERE…SO IT’S NOT “IN” THE CELL) therefore dec contractions.
Tachycardia, headaches, anxiety, transient hyperglycemia, hypokalemia, arrythmias
Severe= pulmonary edema
TERBUTALINE HAS BLACK BOX WARNING TO STOP AFTER 24-48 HOURS
Magnesium sulfate mech? Side effects?
Testing for toxicity?
TOCOLYTIC
Calcium antagonist and membrane stabilizer: competes with calcium for entry into cells.
Flushing, headaches, fatigue, diplopia…but LESS SEVERE than with ritodrine and terbutaline.
Doses more than 10 mg/dL can result in respiratory depression, hypoxia, cardiac arrest.
Test DTRs… depressed at levels less than 10 mg/dl
Calcium channel blocker
TOCOLYTIC
Decrease influx of calcium into smooth muscle cells which dec ctx.
Nifedipine oral.
Headaches, flushing, dizziness.
Prostaglandin inhibitors
TOCOLYTIC
Indomethacin …good for mom bad for baby. Need to monitor AFI for development of oligohydramnios.
Blocks COX and decreases the levels of prostaglandins, which decreases intracellular calcium levels, thereby dec myometrial ctx.
Minimal maternal side effects but lots of fetal complications like ductus arteriosus constriction, plum hypertension, oligohydramnios secondary to renal failure.
PROSTAGLANDINS
INDUCING AGENTS
Increase the intracellular levels of calcium and enhance myometrial gap junction function which INCREASES myometrial ctx.
What do you do with suspected CPD?
Trial of labor anyway
Factors associated with breech presentation
- Previous breech
- Uterine anomalies
- Poly or oligo hydramnios
- Multiple gestation
- PPROM
- Hydrocephaly or anencephaly
Compound presentation
1/1000 but when baby has an extremity coming out with head
Prolonged decel vs. bradycardia?
Prolonged decel is rate below 100-110 for longer than 2 min.
Brady cardia is for longer than 10 min.
Puerperium definition?
First 6 weeks postpartum
Is ibuprofen safe in pregnancy?
Until around wk 32, when premature closure of the ductus arteriosus becomes a risk
