OB Flashcards
Gynecoid Pelvis
- Normal female pelvis
- Round shape
- Blunt, somewhat widely separated ischial spines
- Diagonal conjugate measures 12.5 to 13 cm
Fertilization
Occurs in the ampulla (outer third) of the uterine (fallopian) tube
Implantation
- 6 to 8 days after ovulation
- Blastocyst secretes HCG to ensure that the corpus luteum remains viable and secretes estrogen and progesterone for the first 2-3 months of gestation.
Amniotic Fluid
- 800-1200 mL by end of pregnancy
- Fx: Surrounds, cushions, and protects fetus; allows fetal movement; maintains the body temp of fetus; contains fetal urine and is a measure of fetal kidney function
Placenta
- Formed from the chorion (made by the blastocyst); begins to form at implantation; complete by week 12
- Highly vascularized
- Fx: exchange site for nutrients and waste products between the fetus and mother; produces hormones to maintain pregnancy (assumes full production of hormones by 12th week); transfers maternal immunoglobulin
- By week 10 and 12: genetic testing can be done via chorionic villus sampling (CVS).
Fetal Circulation
-2 Arteries, 1 Vein
-Arts: deox blood, Vein: exy blood
-FHR: 160 to 170 bpm 1st tri; 110 to 160 bpm near or at term (about 2x maternal HR)
-Bypass: Ductus Arteriosus- pulmonary artery to aorta
Ductus Venosus- umbilical vein to to inferior vena cava
Foramen Ovale- opening between rt and lf atria
Pregnancy Signs
Presumptive: Amenorrhea; N/V; Inc size/fullness of breasts; pronounced nipples; Polyuria; Fatigue; Discoloration of vaginal mucosa; Quickening (usually 16th-20th week)
Probable: Positive HGC; Uterine enlargement; Goodell’s sign ( softening of cervix at beginning of 2nd mo of preg); Chadwick’s sign (Violet coloration of cervix/vagina/vulva approx. week 6); Hegar’s sign (Compressibility and softening of the lower uterine seg that occurs approx week 6); Ballottement (rebounding of the fetus against palpation); Braxton Hick’s contractions
Positive: Outline of fetus via radiography or ultrasound; FHR by doppler at 10-12 weeks or fetoscope at 20 weeks; Active fetal movements palpated
Fundal Height
16 weeks: approx. halfway between pubis symphysis and umbilicus
20 to 22 weeks: approx. at umbilicus
18-30 weeks: ht in cm = fetal age +/- 2 cm
36 weeks: at xiphoid process
Supine Hypertension
- 2nd and 3rd trimester
- result of pressure of the uterus on the inferior vena cava
Maternal Risk Factors Ages
Age: <20 and >35
Antepartum Diagnostic Testing
1st 28 to 32 weeks: Every 4 weeks
32 to 36 weeks: Every 2 weeks
36 to 40 weeks: Every week
Rh negative mother
Rhogam shot at 28 weeks and after birth
Amniocentisis
-15 to 20 weeks ideal
-Ultrasound guided
-Full bladder <20 weeks; Empty >20 weeks
-Supine during; Left side after
Risks: Maternal hemorrhage; infection; Rh isoimmunization; Abruptio placentae; Amniotic fluid emboli; Premature rupture of membranes
Weight Gain
25 to 35 lbs
An inc of 300 kcal/day for pregnancy
An inc of 500 kcal/day for lactation
Abortion Intervention
- Count perineal pads to evaluate blood loss.
- Save any expelled tissue and clots.
Anemia
- Predisposes the patient to postpartum infection
- Monitor H&H every 2 weeks
- Take iron between meals and with Vit C. Avoid tea and milk products.
Blood Volume
- Increases by 50%
- Heart enlarges to accommodate
- Blood vol peaks weeks 32 to 34. Dec slightly to week 40.
Chorioamnionitis
- Bacterial infection of the amniotic cavity
- Causes: premature rupture of membranes; vaginitis; ammniocentsis; intrauterine procedures
- Result: Postpartum endometritis; neonatal sepsis
DM
- 1st tri: insulin needs dec
- 2nd and 3rd tri: placental hormones cause insulin resistance leading to a need for inc insulin
- Watch for PP hypoglycemia
- May not need insulin for 1st 24 hrs
- Gest DM: occurs during 2nd or 3rd tri; Tx usually diet, sometimes insulin; oral hypoglycemic meds are unsafe
Ectopic Pregnancy
- Missed period
- Abdominal pain
- Vaginal spotting and bleeding that is dark red or brown
- Rupture: Ince pain, referred shoulder pain, signs of shock
Fetal Death
- older than 20 weeks gestation
- S/S: Absence of fetal movement/heart tones/growth; dec in fundal height; maternal weight loss; no evidence of cardiac activity
TORCH
Toxoplasmosis Other (HIV, Syphilis, HBV, WEst Nile, etc) Rubella Cytomegalovirus Herpes Simplex Virus
Group B Strep
Dx: Vaginal and Rectal cultures between 35 and 37 weeks gestation
TB
Trans: Transplacental is rare; Can occur during birth through aspiration of infected amniotic fluid; in newborn: contact with infected indiv
Maternal Risk: Active disease during preg has been associated with an inc in hypertensive disorders of pregnancy
4 P’s of Labor
Powers: Uterine Contractions
Passageway: Bony pelvis, Cervix, Pelvic Floor, Vagina, introitus (external opening of vagina)
Passenger: Fetus, Membranes, Placenta
Psyche: Woman’s emotional structure that can determine her entire response to labor and influence physiological and psychological copping with the labor process; the mother may experience anxiety or fear
Fetal Positioning
Attitude: Relationship of fetal body parts to one another; Normal: Flexion (fetal position)
Lie: Relationship of the spine of the fetus to the spine of the mother
Presentation: Portion of the fetus that enters the pelvis first; Cephalic/Breech/Shoulder
Presenting Part: the specific fetal structure lying nearest to the cervix
Station: Measurement of the progress of descent in cm above or below the midplane from the presenting part to the ischial spine;
Minus Station: above the ischial spine;
Station 0: at the ischial spine
Plus Station: below the ischial spine
Engagement: When the widest part has passed the inler; usually corresponds to a 0 station
Fetal Monitoring
External fetal monitoring: non-invasive
Internal fetal monitoring: Invasive; requires rupturing the membranes and attaching an electrode to the presenting part; must be dialated 2-3cm
Bradycardia: <110 bpm for 10 mins or longer
Tachycardia: >160 bpm for 10 mins or longer
Accelerations: inc of at least 15 bpm over baseline for at least 15 secs; reassuring
Early Decelerations: Usually remains above 100 bpm; occur during contractions; Not associated with fetal compromise and require no intervention
Late Decelerations: Nonreassuring patterns that reflect impaired placental exchange or uteroplacental insufficiency; defree of the fall in the heart rate from baseline is not related to the amount of uteroplacental insufficiency
Variable Decelerations: Caused by conditions that restrict flow throught the umbilical cord;
Interventions: position change for mom; admin O2; discontinue oxytocin; mom VS; amnioinfusion as perscribed
Stages of Labor
Stage 1: Effacement and Dilation of the Cervix 3 Phases Phase 1: Latent (1-4 cm dilation) Phase 2: Active (4-7 cm dilation) Phase 3: Transition (8-10 cm dilation)
Stage 2: Expulsion of the fetus
Stage 3: Separation and Expulsion of Placenta
- 5 to 30 mins after birth of baby
Stage 4: Physical Recovery
- 1 to 4 hours
Oxytocin
Discontinue if:
- Contraction frequency <2 mins
- Contraction duration >90 secs
- Fetal distress noted
Goal: frequency 2-3 mins; duration 60 secs
Amniotomy
- Artificial Rupture of Membranes (AROM)
- Performed at 0 or plus station
- Inc risk of cord prolapse or infection
- Inc of variable decels after AROM
External Version
- External manipulation of the fetus from an unfavorable presentation into a favorable one for birth
- Indicated for an abnormal presentation that exists after 34 weeks gestation
- After: nonstress test to evaluate fetal well-being
Placenta accreta
- Abnormally adherent placenta
- placenta penetrates the uterine muscle itself
- Monitor for hemorrhage and shock
Placenta Previa
- Placenta imporoperly implanted in the lower uterine segment near or over the internal cervical os
- total, partial, marginal
- No digital vaginal examination
- sudden onset of painless, bright red bleeding
- uterus is soft, relaxed, and nontender
Abruptio Placentae
- Premaure separation of the placenta from the uterine wall after 20 weeks’ gestation and before the birth of the baby
- Dark red vaginal bleeding
- Uterine pain/tenderness
- uterine rigidity
- severe abdominal pain
- signs of fetal distress
- signs of maternal shock if bleeding is excessive
Preterm Labor
After 20 weeks and before 37 weeks
Premature Rupture of Membranes
Spontaneous rupture of the amniotic membrane befor the onset of labor
Precipitous Labor and Delivery
Labor that lasts less than 3 hours
- Have precipitous delivery tray available
- Stay with the mother at all times
- Deliver if PCHP is not available
Amniotic Fluid Embolism
- Escape of amniotic fluid into the maternal circulation
- Usually fatal to mother
- Abrupt onset of resp distress and chest pain
- Cyanosis
- Fetal bradycardia and distress if delivery has not occurred at the time of the embolism
- Admin 8 to 10 L/min O2
- Prepare for intubation and ventilation
- Position on side
- IV fluids, blood products, and meds for coag failure
- Prepare for emer delivery after woman is stabilized
Fetal Distress Signs and Interventions
- FHR <110 or >160 bpm
- Meconium-stained amniotic fluid
- Fetal hypoactivity or hyperactivity
- Pregressive dec in baseline variability
- Severe variable decels
- Late decels
- Place mother in a lateral position
- Admin O2 at 8 to 10 L/min
- Discontinue oxytocin infusion
- Monitor maternal and fetal status
Postpartum Period
-Starts immediately after birth and is usually complete by week 6
Involution of Uterus
- Uterus dec from 2 lb to 2 oz
- Endometrium regenerates
- Fundus height dec about 1 cm per day (day 0: just above belly button)
- 10 days PP: uterus cannot be palpated abdominally
- Flaccid fundus indicates uterine atony (massage it)
- Tender fundus indicates infection
Lochia
-Uterine discharge fro blood vessels from the placental site and debis from the decidua
- Rubra: Bright red; delivery to PP day 3
- Serosa: Brownish-pink; PP day 4 to 10
- Alba: White discharge; PP day 11 to 14
- Odor: normal menstrual flow
- Dec in amount daily
- Inc with ambulation
Amount of Lochia (as measured by amount present on menstrual pad in an hour)
- Scant: < 2.5 cm/ 1 in
- Light: < 10 cm/ 4 in
- Moderate: < 15 cm/ 6 in
- Heavy: Fully sturated
- Excessive: Pad saturaeated in 15 mins
Breast Milk
Colostrum for 48 to 72 hours
Engorgement occurs approx. day 4
Post Partum Interventions
- VS (temp may inc in 1st 24 hrs; PR may be down to 50; RR and BP should be normal)
- Pain Level
- Fundus (with an empty bladder): ht, consistency, location
- Lochia: color, amount, odor
- Check breasts for engorgement
- Perineum for swelling or discoloration
- Perineal lacerations or episiotomy for healing
- Incisions or dressings after C-section
- I/O
- Encourage frequent voiding
- Monitor bowel status
- Encourage ambulation
- Extremities for thrombophlebitis
- Rhogam admin within 72 hrs PP
- Rubella immunization admin
- Parent-Newborn bonding
- Mother’s emotional status
Hemorrhage and Shock
- Bleeding of >500 mL after delivrey
- Early (1st 24 hrs) or Late (>24 hrs)
Causes:
- Uterine Atony
- Laceration of the cervix or vagina
- Hematoma development in the cervix, perineum, or labia
- Retained placental fragments
Predisposing Factors:
- Hx of PP Hem
- Placenta Previa
- Abruptio placentae
- Overdistention of the uterus
- Infection
- Multiparity
- Dystocia or prolonged labor
- Operative Delivery (C-section, forceps, intrauterine manipulation.)
S/S: Significant bleeding (perineal pad is soaked within 15 mins); Restlessness; inc HR; dec BP; cool/clammy skin; ashen/grayish color
Interventions:
Notify RN; Massage uterus; O2 (8 to 10 L/min); VS; Lay on side; meds; LR or NS; Blood/Blood products; Cathetre; Prep for surgery
Infection
Any infection of the reproductive organs that occurs within 28 days of delivery or abortion
