OBGYN - Normal and Abnormal Labor
From Iusmicm
(Difference between revisions)
Line 3: | Line 3: | ||
==Definitions== | ==Definitions== | ||
*Labor: regular / rhythmic contractions, cervical dilation and effacement. | *Labor: regular / rhythmic contractions, cervical dilation and effacement. | ||
- | **Labor is considered "preterm" if it commences before 37 weeks EGA (estimated gestational age) | + | **'''Must have cervical change''' to call it labor. |
+ | **Dilation: cervix develops a wider opening. | ||
+ | **Effacement: becomes shorter. | ||
+ | *Labor is considered '''"preterm" if it commences before 37 weeks EGA''' (estimated gestational age) | ||
**10-12% of pregnancies include preterm labor. | **10-12% of pregnancies include preterm labor. | ||
- | + | *Labor is considered '''"postdates" if it commences after 42 weeks EGA.''' | |
- | *Braxton Hicks contractions are contractions of a weak or irregular nature. | + | *'''Braxton Hicks contractions are contractions of a weak or irregular nature.''' |
==Physiology of Labor== | ==Physiology of Labor== | ||
*There are many factors that play a role in the coordinated contraction of all the uterine smooth muscle for labor. | *There are many factors that play a role in the coordinated contraction of all the uterine smooth muscle for labor. | ||
+ | |||
+ | |||
*Progesterone and Relaxin are key regulating factors in animals. | *Progesterone and Relaxin are key regulating factors in animals. | ||
- | ** | + | **'''Relaxin does not play a role in humans.''' |
+ | **When 17 alpha-hydroxyprogesterone caproate is given, we see fewer preterm contractions '''so we know progesterone plays a role but we don't see it physiologically'''. | ||
+ | **'''Progesterone levels don't drop until after the ''placenta'' is delivered.''' | ||
+ | |||
+ | |||
*Gap juctions of the uterine smooth muscle are increased near term. | *Gap juctions of the uterine smooth muscle are increased near term. | ||
**Presumably to augment myofiber-myofiber communication for a well sequenced contraction. | **Presumably to augment myofiber-myofiber communication for a well sequenced contraction. | ||
- | *Oxytocin, surprisingly, shows '''no change in blood levels'''. | + | **Allow easy ability for electrical potential to cross. |
+ | |||
+ | |||
+ | *Oxytocin, surprisingly, shows '''no change in blood levels''' but there are '''increased number of oxytocin receptors'''. | ||
**Oxytocin receptors, however are elevated. | **Oxytocin receptors, however are elevated. | ||
- | + | **Oxytocin does promote the influx of calcium ions (and therefore increased contractions). | |
+ | **There is a '''paracrine oxytocin production''' from the ''dicidual and placenta'' with subsequent increase in receptors in the myometrium. | ||
+ | **Made in the posterior pituitary. | ||
+ | |||
+ | |||
*Several prostaglandins are elevated for labor: PGE1, PGE2, PGF2alpha | *Several prostaglandins are elevated for labor: PGE1, PGE2, PGF2alpha | ||
+ | **Makes collagenase to help '''break down collagen of the cervix to allow dilation and effacement.''' | ||
+ | |||
+ | |||
*Mother becomes more sensitive to changes in Ca at term. | *Mother becomes more sensitive to changes in Ca at term. | ||
**This is presumably because the uterine muscle is storing up more and more Ca to augment contraction. | **This is presumably because the uterine muscle is storing up more and more Ca to augment contraction. | ||
+ | |||
+ | |||
*Like prostaglandins, many cytokines are elevated: IL-1, IL-6, IL-8, TNF-alpha. | *Like prostaglandins, many cytokines are elevated: IL-1, IL-6, IL-8, TNF-alpha. | ||
+ | **Intermediate reactions in the labor pathway. | ||
+ | **'''Infections can sometimes induce these types of cytokines and thus ''induce labor'''''. | ||
+ | **NO is another intermediate reactor. | ||
==Labor and Delivery Admission== | ==Labor and Delivery Admission== | ||
*The workup for a L&D admission includes: | *The workup for a L&D admission includes: | ||
- | **H&P | + | **H&P: |
- | **Fetal monitoring | + | ***Fetal monitoring |
- | **Leopold’s maneuver | + | ***Leopold’s maneuver |
- | **Vaginal exam | + | ***Vaginal exam |
- | ***R/o (rule out) placenta previa and ROM first | + | ****R/o (rule out) placenta previa and ROM first |
- | ***Cervical dilation / effacement / station and fetal position | + | ****Cervical dilation / effacement / station and fetal position |
===Fetal Monitoring=== | ===Fetal Monitoring=== | ||
- | |||
*With fetal monitoring we are concerned with the baby's heart rate and the uterine pressure. | *With fetal monitoring we are concerned with the baby's heart rate and the uterine pressure. | ||
+ | *There are several technical methods for fetal monitoring. | ||
+ | **We can monitor externally via ultrasound and pressure transducers. | ||
+ | **We can monitor internally (if the membranes are ruptured) by putting a pressure transducer into the uterine cavity. | ||
+ | ***A clip on the baby's scalp can mark each R wave. | ||
- | + | ====Fetal Monitoring - Normals==== | |
- | *For baby's heart rate, the baseline should be around | + | *'''For baby's heart rate, the baseline should be around 110-160 bpm.''' |
*We are looking for: variability, accelerations / decelerations | *We are looking for: variability, accelerations / decelerations | ||
- | + | *For uterine pressure (contractions) we are looking for: '''frequency, duration, uterine tone.''' | |
- | + | **Tone is important because the baby gets better blood flow when the uterus is resting. | |
- | *For uterine pressure (contractions) we are looking for: frequency, duration, uterine tone. | + | |
====Variability and Accelerations / Decelerations==== | ====Variability and Accelerations / Decelerations==== | ||
*Variability: | *Variability: | ||
**Absent: 0-2 bpm | **Absent: 0-2 bpm | ||
+ | ***Start worrying about fetal acidosis. | ||
+ | ***Fix the environment or get the baby out. | ||
**Minimal: 3-5 bpm | **Minimal: 3-5 bpm | ||
- | **Moderate: 6-25 bpm | + | **'''Moderate: 6-25 bpm''' (ideal). |
**Marked: saltatory, >25 bpm | **Marked: saltatory, >25 bpm | ||
*Fetal Monitoring: | *Fetal Monitoring: | ||
- | ** | + | **Good, classic accelerations '''go up by 15 beats per minute and last for 15 seconds'''. |
- | + | **If the pregnancy is less than 34 weeks, "10x10" is acceptable. | |
- | + | ||
- | * | + | |
- | * | + | |
- | + | ||
- | + | ||
- | + | ||
- | + | ||
- | + | ||
- | + | ||
- | + | ||
=====Decelerations===== | =====Decelerations===== | ||
- | *Early declerations: occur with cntx | + | *'''Early declerations: occur with cntx''' |
+ | **Start and end with the contraction | ||
**'''Non worrisome''' | **'''Non worrisome''' | ||
- | **Head compression leads to vagal stimulation | + | **Head compression leads to vagal stimulation at the posterior fontanelle |
**Recall that vagus carries parasympathetics to the heart | **Recall that vagus carries parasympathetics to the heart | ||
- | *Late decelerations: begin at peak of cntx or after | + | *'''Late decelerations: begin at peak of cntx or after''' |
- | **Fetal hypoxia is usually the culprit of late decelerations. | + | **'''Fetal hypoxia''' is usually the culprit of late decelerations. |
- | *Variable: can occur at any time | + | **Occurs due to chemoreceptors in the carotid arch that sense the decreased pO2 leading to vasoconstriction and then bradycardia |
- | **Variable decelerations should raise one's suspicion for cord compression | + | *'''Variable: can occur at any time''' |
+ | **Variable decelerations should '''raise one's suspicion for cord compression''' | ||
Line 80: | Line 100: | ||
**'''Severity of variable decelerations are a function of blood pressure and duration''' | **'''Severity of variable decelerations are a function of blood pressure and duration''' | ||
- | ==== | + | ====Categories of Heart Tracings==== |
+ | *Category 1: | ||
+ | **Baseline rate: 110-160 bpm | ||
+ | **Baseline FHR variability is moderate | ||
+ | **Accelerations: present or absent | ||
+ | **Late or variable decelerations absent | ||
+ | *Early decelerations present or absent | ||
+ | |||
+ | |||
+ | *Category 2: | ||
+ | **Everything not in 1 or 3 | ||
+ | |||
+ | |||
+ | *Category 3: | ||
+ | **Absent baseline variability ('''recall, a sign of acidosis''') | ||
+ | **Recurrent late decelerations | ||
+ | **Recurrent variable decelerations | ||
+ | **Bradycardia | ||
+ | **Sinusoidal pattern ('''a sign of fetal hypoxia with severe anemia'''; think Rh disease) | ||
===Fetal Lie, Presentation, Attitude, and Position=== | ===Fetal Lie, Presentation, Attitude, and Position=== | ||
- | *Clinical: | + | *Clinical: abdomenal palpation, auscultation of fht’s, vaginal exam |
*Studies: u/s, x-ray, MRI | *Studies: u/s, x-ray, MRI | ||
+ | **These are done very rarely as we can determine the lie and presentation rather easily via physical examination. | ||
====Definitions==== | ====Definitions==== | ||
- | *'''Lie: relation of long axis of fetus to long axis of mother''' | + | *'''Lie: relation of long axis of fetus to long axis of mother.''' |
**Longitudinal | **Longitudinal | ||
**Transverse | **Transverse | ||
Line 93: | Line 132: | ||
- | *'''Presentation: part foremost in the pelvis''' | + | *'''Presentation: part of baby foremost in the pelvis''' |
**Cephalic | **Cephalic | ||
- | **Breech | + | **Breech (bottom) |
**Shoulder | **Shoulder | ||
+ | **Face | ||
**'''Compound:''' | **'''Compound:''' | ||
- | ***Head / hand -> watch | + | ***Head / hand -> watch (usually resolves itself; may apply a noxious stimuli to the hand) |
- | ***Head / foot-> c-section | + | ***Head / foot-> c-section (will not resolve itself; requires c/s) |
*Cord prolapse (funic presentation): an '''emergency'''. | *Cord prolapse (funic presentation): an '''emergency'''. | ||
+ | **When the cord drops into the vagina. | ||
+ | **Must move quickly to c/s. | ||
- | *'''Attitude: | + | *'''Attitude: how the baby presents its head''' |
- | ** | + | **Normal attitude is folded on itself w/ flexed head |
- | *'''Position: relation of presenting part to maternal pelvis''' | + | *'''Position: relation of presenting part to maternal pelvis anterior aspect''' |
- | ** | + | **When the baby ''presents cephalically'', the reference point on the baby to be referenced to the anterior pubis of the mother is the '''occiput''' |
- | ** | + | **When the baby ''presents facially'', the reference point is the '''mentum''' |
- | ** | + | **When the baby ''presents as a breech'', the reference point is the '''sacrum''' |
- | ** | + | **When the baby ''presents transverse'' (shoulder), the reference point is the '''acromion process''' |
====Fetal Attitude==== | ====Fetal Attitude==== | ||
*There are a variety of ways the fetus can present at the os; these are called attitudes: | *There are a variety of ways the fetus can present at the os; these are called attitudes: | ||
**Full flexion (A) | **Full flexion (A) | ||
+ | ***Normal, smallest diameter. | ||
**Military attitude (B) | **Military attitude (B) | ||
**Brow presentation (C) | **Brow presentation (C) | ||
Line 123: | Line 166: | ||
*Leopold’s Maneuver can be used to determine the attitude of the fetus. | *Leopold’s Maneuver can be used to determine the attitude of the fetus. | ||
+ | **First maneuver: what is occupying the fundus? | ||
+ | ***Soft like a butt or hard like a head? | ||
+ | **Second maneuver: on which side is the fetal spine? | ||
+ | ***Third maneuver: what is presenting at the pelvis? | ||
+ | ***Soft like a butt or hard like a head? | ||
+ | **Fourth maneuver: what is the attitude, based on the flexion / extension of the head? | ||
+ | *Can correlate with CT if there is any questions. | ||
+ | |||
http://www.sciencephoto.com/image/288555/350wm/M8000133-Leopold_s_Maneuver-SPL.jpg | http://www.sciencephoto.com/image/288555/350wm/M8000133-Leopold_s_Maneuver-SPL.jpg | ||
====Vaginal Exam==== | ====Vaginal Exam==== | ||
- | * | + | *We are trying to determine if the cervix is starting to dilate or efface. |
+ | *We describe effacement as a percent of normal length: | ||
+ | **Normal length of a cervix is 4cm. | ||
+ | **So if the cervix is observed as being 2 cm effaced, we call it 50%. | ||
- | *Station: | + | *Station: the lowest point of the fetus in reference to the ischial spines. |
+ | **The stating is described as -1 (and so on, for every centimeter) it is above the ischial spines. | ||
+ | **The station is described as +1 (and so on, for every centimeter) it is below the ischial spines. | ||
*Position: | *Position: | ||
+ | **Most common is cephalic. | ||
+ | **Use the occiput as the baby reference point when describing position against the maternal anterior pubis. | ||
+ | **'''"right" and "left" shifts describe maternal right and left''' | ||
+ | **To determine which aspect is the occiput, recall there are ant and post fontanelles (along which to orient) and the frontal suture (to identify the anterior aspect of the baby). | ||
*Pelvimetry: | *Pelvimetry: | ||
- | ** | + | **Performed at the first pre-natal visit and upon admission for L&D. |
- | ** | + | **Describes adequacy of the pelvis for baby delivery. |
+ | **Measures pelvic inlet, the midpelvis, and the pelvic outlet. | ||
=====Pelvic Inlet===== | =====Pelvic Inlet===== | ||
- | * | + | *True pelvic inlet measurement is from superior pubic ramus to the sacral prominence. |
- | *True obstetric conjugate = diagonal conjugate – 1.5 to 2.0 cm | + | **However, this can't be measured directly so we measure it indirectly. |
+ | **True conjugate is also called the obstetric conjugate. | ||
+ | |||
+ | |||
+ | *The diagonal conjugate is measured with one's third finger, along toward the thumb. | ||
+ | *'''True obstetric conjugate = diagonal conjugate – 1.5 to 2.0 cm''' | ||
+ | |||
+ | |||
+ | *'''Diagonal conjugate: >11.5 cm is adequate''' | ||
=====Midpelvis===== | =====Midpelvis===== | ||
+ | *Sacrum – hallow versus shallow (flat): | ||
+ | **Hallow is concave like a bowl of soup and gives ''more room for baby moving''. | ||
+ | |||
+ | |||
*Ischial spines – blunt vs. prominent | *Ischial spines – blunt vs. prominent | ||
+ | **blunt is better; more room | ||
+ | |||
+ | |||
*Pelvic sidewalls | *Pelvic sidewalls | ||
**Parallel = OK | **Parallel = OK | ||
**Divergent = good | **Divergent = good | ||
**Convergent = bad | **Convergent = bad | ||
- | |||
=====Pelvic Outlet===== | =====Pelvic Outlet===== | ||
- | *Bituberous diameter > 6-8 cm | + | *Bituberous diameter: |
- | *Pubic arch > 90 degrees | + | ** > 6-8 cm is good |
+ | **Measured by placing fist up against the butt. | ||
+ | |||
+ | |||
+ | *Pubic arch: | ||
+ | ** > 90 degrees is good | ||
===Stages of Labor=== | ===Stages of Labor=== | ||
- | *1st Stage: beginning of cervical dilation to complete dilation | + | *1st Stage: beginning of cervical dilation to complete dilation (10 cm) |
*2nd Stage: complete dilation to delivery of fetus | *2nd Stage: complete dilation to delivery of fetus | ||
- | *3rd Stage: delivery of placenta | + | *3rd Stage: delivery of placenta |
+ | **up to 30 minutes | ||
*4th Stage: first hour after delivery of placenta | *4th Stage: first hour after delivery of placenta | ||
+ | **Big fluid shift, high risk of post-partum hemorrhage. | ||
+ | **Monitoring mom for vitals | ||
+ | **Monitoring firmness of uterus (should remain firm to inhibit hemorrhage by pressing layers of endometrium together) | ||
- | ===Cardinal Movements of Labor====*Engagement | + | ===Cardinal Movements of Labor==== |
- | *Flexion | + | *Engagement |
+ | *Flexion (of the head) | ||
*Descent | *Descent | ||
*Internal rotation | *Internal rotation | ||
Line 168: | Line 253: | ||
*External rotation | *External rotation | ||
*Expulsion | *Expulsion | ||
+ | |||
+ | |||
+ | *If the face is anterior, it can still extend. | ||
+ | *If ''mentum-posterior'', there can be no extension, so it cannot deliver. | ||
===Labor Curve=== | ===Labor Curve=== | ||
- | + | *The first phase of minimal cervical change is latent phase. | |
+ | **Minutes, hours, days! | ||
+ | *Active phase | ||
+ | **> 1 cm change / hour | ||
+ | *Baby will move from -5cm station to 0 to +5 as it delivers. | ||
===Prolonged / Arrested Labor=== | ===Prolonged / Arrested Labor=== | ||
+ | *When labor isn't moving along, consider your '''3 Ps''' | ||
*'''P'''ower: uterine contractions | *'''P'''ower: uterine contractions | ||
+ | **Are they strong enough? | ||
+ | **Give oxytocin? | ||
*'''P'''elvis: adequate? | *'''P'''elvis: adequate? | ||
+ | **Do your pelvimetry to make sure pathway is sufficient | ||
*'''P'''assenger: EFW, position / attitude | *'''P'''assenger: EFW, position / attitude | ||
+ | **Is the baby too big? | ||
+ | **Is the position wrong? (occiput posterior) | ||
+ | **Is the attitude wrong? (military) | ||
===Dysfunctional Labor=== | ===Dysfunctional Labor=== | ||
Line 187: | Line 287: | ||
|>20 hr | |>20 hr | ||
|>14 hr | |>14 hr | ||
- | |Rest, AROM, | + | |Rest, AROM (augmented rupture of membranes; helps augment maternal environment for labor), Pitocin (oxytocin) |
|- | |- | ||
!Protracted dilation | !Protracted dilation | ||
Line 212: | Line 312: | ||
*History | *History | ||
**''Caedere -> caesura'': to cut; ''seco'': to cut. | **''Caedere -> caesura'': to cut; ''seco'': to cut. | ||
- | **Francois Rousset (1581) | + | **"Cut Cut" |
- | **Max Sanger (1882)- Leipzig | + | *Francois Rousset (1581) |
+ | **First reported case with survival. | ||
+ | **Questionable | ||
+ | *Max Sanger (1882)- Leipzig | ||
+ | **Work on the American frontier | ||
+ | **Sewed the womb shut! (Whoa!) | ||
+ | **Crazy b/c the womb was considered an awful, evil thing, that shouldn't be sewn shut b/c all those bad humors would stay inside! | ||
+ | |||
+ | |||
*Most common surgical procedure | *Most common surgical procedure | ||
- | **1965 <5%, 1996 | + | **1965: <5%, 1996: 20.7%, 2004: 29.1% |
- | + | *No change in cerebral palsy rate | |
====C-section - Techniques==== | ====C-section - Techniques==== | ||
- | *Uterine Incisions | + | *Uterine Incisions |
- | + | *Low transverse | |
- | **Low verticle | + | **The most common way because it runs with the grain of the muscular fibers. |
- | + | **Also, this area does less labor contracting so next pregnancy is less likely to result in rupture. | |
- | + | *Low verticle | |
+ | *Classical | ||
+ | *Kerr | ||
====C-section - Indications==== | ====C-section - Indications==== | ||
Line 229: | Line 339: | ||
=====Fetal C-section Indications===== | =====Fetal C-section Indications===== | ||
*Distress / intolerance of labor | *Distress / intolerance of labor | ||
+ | **'''FHT of category 2 or 3''' | ||
*Malpresentation (breech, transverse) | *Malpresentation (breech, transverse) | ||
*Twins, multiples | *Twins, multiples | ||
- | ** | + | **'''Vertex / Vertex = allow to labor''' |
*Some congenital anomalies | *Some congenital anomalies | ||
**NTD | **NTD | ||
=====Maternal-Fetal C-section Indications===== | =====Maternal-Fetal C-section Indications===== | ||
- | *Arrest of active labor | + | *'''Arrest of active labor''' |
+ | **Pretty common | ||
*Failed induction of labor (?) | *Failed induction of labor (?) | ||
- | *Placenta previa, vasa previa | + | *'''Placenta previa, vasa previa''' |
+ | **When the placenta covers the cervical os. | ||
+ | **When the placental vessels course between baby and os. | ||
+ | ***50% mortality post-rupture! | ||
*Active HSV outbreak | *Active HSV outbreak | ||
*HIV+ (viral load >1000/ml) | *HIV+ (viral load >1000/ml) | ||
- | *EFW > 4500 - 5000 | + | **If mom is on ARV therapy, there is no decrease in transmission with c/s. |
+ | *EFW > 4500 - '''5000 grams''' (increasing risk of shoulder dystocia) | ||
+ | **Use u/s to estimate weight. | ||
=====Maternal C-section Indications===== | =====Maternal C-section Indications===== | ||
Line 248: | Line 365: | ||
*Cervical cancer | *Cervical cancer | ||
*Abdominal cerclage | *Abdominal cerclage | ||
- | *Prior c-section | + | *'''Prior c-section''' |
+ | **Risk of uterine rupture is 0.5-1% | ||
+ | **Can be catastrophic | ||
*Prior vaginal colporrhaphy | *Prior vaginal colporrhaphy | ||
*Vaginal delivery contraindicated medically | *Vaginal delivery contraindicated medically | ||
*Pregnant??? | *Pregnant??? | ||
+ | **No! | ||
====C-section - Risks==== | ====C-section - Risks==== | ||
*At time of surgery / Immediate post-op | *At time of surgery / Immediate post-op | ||
- | *Infection: endometritis, wound infection, septic pelvic thrombophlebitis (SPT) | + | *'''Infection: endometritis, wound infection, septic pelvic thrombophlebitis (SPT)''' |
*Bleeding: transfusion, hysterectomy | *Bleeding: transfusion, hysterectomy | ||
*Damage to fetus | *Damage to fetus | ||
+ | **Very small; no larger than with vaginal delivery. | ||
*Damage to adjacent organs | *Damage to adjacent organs | ||
- | *Subsequent pregnancy | + | |
+ | |||
+ | *Subsequent pregnancy: | ||
+ | **Adhesions | ||
**Uterine rupture | **Uterine rupture | ||
- | **Placenta previa | + | **Placenta previa (when the placenta covers the os) may convert to accreta (when the placenta invades the myometrium). |
- | ***0 –> 5% | + | **Accreta carries huge risks because there is often massive bleeding. |
+ | **Accreta puts the mother a risk of death. | ||
+ | **'''That is, placenta previa with a previous c/s has a very high risk of being bad!''' | ||
+ | ***0 –> 5% (number of previous c/s, risk of accreta given a placenta previa) | ||
***1 –> 24% | ***1 –> 24% | ||
***2 –> 48% | ***2 –> 48% | ||
***3 –> 67% | ***3 –> 67% | ||
- | + | There will be a test question on prior c/s and placenta previa. | |
+ | |||
===Operative Vaginal Delivery=== | ===Operative Vaginal Delivery=== | ||
- | *Forceps and vacuum | + | *Forceps and vacuum can be used to guide the baby's head out of the pelvis. |
+ | *There are many different types and procedures. | ||
====Operative Vaginal Delivery - Classification==== | ====Operative Vaginal Delivery - Classification==== | ||
+ | *We want, first, to be sure the baby has reached the pelvic inlet. | ||
+ | |||
+ | *Didn't talk about any of this: | ||
*Outlet: scalp visible at introitus w/out separating labia; no rotation | *Outlet: scalp visible at introitus w/out separating labia; no rotation | ||
*Low: leading point of skull at or below +2 cm station | *Low: leading point of skull at or below +2 cm station | ||
Line 289: | Line 421: | ||
*Fetal skull engaged in pelvis | *Fetal skull engaged in pelvis | ||
*Empty bladder | *Empty bladder | ||
- | *Position! Position! Position! | + | *'''Position! Position! Position!''' |
+ | **Before we put anything on the baby's head, we have to know the position so we don't break the nasal bone or deform the child. | ||
*Adequate pelvis | *Adequate pelvis | ||
*Adequate anesthesia | *Adequate anesthesia | ||
====Operative Vaginal Delivery - Forceps Assisted==== | ====Operative Vaginal Delivery - Forceps Assisted==== | ||
+ | *Use the same angles when applying traction. | ||
+ | *Apply the extension just like in a non-operative vaginal delivery. | ||
====Operative Vaginal Delivery - Risks==== | ====Operative Vaginal Delivery - Risks==== | ||
*Maternal: | *Maternal: | ||
**Vaginal / perineal trauma, damage to rectal sphincter | **Vaginal / perineal trauma, damage to rectal sphincter | ||
+ | **Mostly forceps issues with mom | ||
*Fetal: | *Fetal: | ||
+ | **Mostly vacuum issues with baby | ||
**Cephalohematoma | **Cephalohematoma | ||
**Subgaleal hemorrhage | **Subgaleal hemorrhage | ||
Line 305: | Line 442: | ||
**Intraventricular hemorrhage | **Intraventricular hemorrhage | ||
- | ===Birth Trauma=== | + | ====Birth Trauma==== |
*Caput succedaneum: | *Caput succedaneum: | ||
**Very common | **Very common | ||
**Crosses midline | **Crosses midline | ||
*Subgaleal hemorrhage: | *Subgaleal hemorrhage: | ||
+ | **Does not cross midline | ||
**Rare | **Rare | ||
**Hypovolemia and DIC | **Hypovolemia and DIC | ||
Line 316: | Line 454: | ||
*PP Hemorrhage: >500cc (>1000cc for c/s): | *PP Hemorrhage: >500cc (>1000cc for c/s): | ||
**Atony | **Atony | ||
+ | ***When the uterus won't contract. | ||
+ | ***Linings aren't collapsed together to stop bleeding. | ||
**Lacerations (cervix, vagina, perineum) | **Lacerations (cervix, vagina, perineum) | ||
**Retained placenta | **Retained placenta | ||
+ | ***Keeps the endometrium layers from coapting (collapsing together). | ||
**Uterine rupture | **Uterine rupture | ||
**Uterine inversion | **Uterine inversion | ||
**Amniotic fluid embolism | **Amniotic fluid embolism | ||
+ | |||
+ | |||
*Endometritis: | *Endometritis: | ||
**Fundal tenderness w/ temperature >38°C x 2 or >38.5°C | **Fundal tenderness w/ temperature >38°C x 2 or >38.5°C | ||
Line 327: | Line 470: | ||
***Prolonged ruptured membranes | ***Prolonged ruptured membranes | ||
***Chorioamnionitis | ***Chorioamnionitis | ||
+ | **'''Treat with broad spectrum antibiotics''' | ||
====PP / Post-Op Fever==== | ====PP / Post-Op Fever==== |
Revision as of 22:14, 14 December 2011
Labor: Normal, Abnormal, and Points Between
Definitions
- Labor: regular / rhythmic contractions, cervical dilation and effacement.
- Must have cervical change to call it labor.
- Dilation: cervix develops a wider opening.
- Effacement: becomes shorter.
- Labor is considered "preterm" if it commences before 37 weeks EGA (estimated gestational age)
- 10-12% of pregnancies include preterm labor.
- Labor is considered "postdates" if it commences after 42 weeks EGA.
- Braxton Hicks contractions are contractions of a weak or irregular nature.
Physiology of Labor
- There are many factors that play a role in the coordinated contraction of all the uterine smooth muscle for labor.
- Progesterone and Relaxin are key regulating factors in animals.
- Relaxin does not play a role in humans.
- When 17 alpha-hydroxyprogesterone caproate is given, we see fewer preterm contractions so we know progesterone plays a role but we don't see it physiologically.
- Progesterone levels don't drop until after the placenta is delivered.
- Gap juctions of the uterine smooth muscle are increased near term.
- Presumably to augment myofiber-myofiber communication for a well sequenced contraction.
- Allow easy ability for electrical potential to cross.
- Oxytocin, surprisingly, shows no change in blood levels but there are increased number of oxytocin receptors.
- Oxytocin receptors, however are elevated.
- Oxytocin does promote the influx of calcium ions (and therefore increased contractions).
- There is a paracrine oxytocin production from the dicidual and placenta with subsequent increase in receptors in the myometrium.
- Made in the posterior pituitary.
- Several prostaglandins are elevated for labor: PGE1, PGE2, PGF2alpha
- Makes collagenase to help break down collagen of the cervix to allow dilation and effacement.
- Mother becomes more sensitive to changes in Ca at term.
- This is presumably because the uterine muscle is storing up more and more Ca to augment contraction.
- Like prostaglandins, many cytokines are elevated: IL-1, IL-6, IL-8, TNF-alpha.
- Intermediate reactions in the labor pathway.
- Infections can sometimes induce these types of cytokines and thus induce labor.
- NO is another intermediate reactor.
Labor and Delivery Admission
- The workup for a L&D admission includes:
- H&P:
- Fetal monitoring
- Leopold’s maneuver
- Vaginal exam
- R/o (rule out) placenta previa and ROM first
- Cervical dilation / effacement / station and fetal position
- H&P:
Fetal Monitoring
- With fetal monitoring we are concerned with the baby's heart rate and the uterine pressure.
- There are several technical methods for fetal monitoring.
- We can monitor externally via ultrasound and pressure transducers.
- We can monitor internally (if the membranes are ruptured) by putting a pressure transducer into the uterine cavity.
- A clip on the baby's scalp can mark each R wave.
Fetal Monitoring - Normals
- For baby's heart rate, the baseline should be around 110-160 bpm.
- We are looking for: variability, accelerations / decelerations
- For uterine pressure (contractions) we are looking for: frequency, duration, uterine tone.
- Tone is important because the baby gets better blood flow when the uterus is resting.
Variability and Accelerations / Decelerations
- Variability:
- Absent: 0-2 bpm
- Start worrying about fetal acidosis.
- Fix the environment or get the baby out.
- Minimal: 3-5 bpm
- Moderate: 6-25 bpm (ideal).
- Marked: saltatory, >25 bpm
- Absent: 0-2 bpm
- Fetal Monitoring:
- Good, classic accelerations go up by 15 beats per minute and last for 15 seconds.
- If the pregnancy is less than 34 weeks, "10x10" is acceptable.
Decelerations
- Early declerations: occur with cntx
- Start and end with the contraction
- Non worrisome
- Head compression leads to vagal stimulation at the posterior fontanelle
- Recall that vagus carries parasympathetics to the heart
- Late decelerations: begin at peak of cntx or after
- Fetal hypoxia is usually the culprit of late decelerations.
- Occurs due to chemoreceptors in the carotid arch that sense the decreased pO2 leading to vasoconstriction and then bradycardia
- Variable: can occur at any time
- Variable decelerations should raise one's suspicion for cord compression
- Variable Decelerations: mild, moderate, and severe.
- Lower the blood pressure the more severe.
- Longer the duration the more severe.
- Severity of variable decelerations are a function of blood pressure and duration
Categories of Heart Tracings
- Category 1:
- Baseline rate: 110-160 bpm
- Baseline FHR variability is moderate
- Accelerations: present or absent
- Late or variable decelerations absent
- Early decelerations present or absent
- Category 2:
- Everything not in 1 or 3
- Category 3:
- Absent baseline variability (recall, a sign of acidosis)
- Recurrent late decelerations
- Recurrent variable decelerations
- Bradycardia
- Sinusoidal pattern (a sign of fetal hypoxia with severe anemia; think Rh disease)
Fetal Lie, Presentation, Attitude, and Position
- Clinical: abdomenal palpation, auscultation of fht’s, vaginal exam
- Studies: u/s, x-ray, MRI
- These are done very rarely as we can determine the lie and presentation rather easily via physical examination.
Definitions
- Lie: relation of long axis of fetus to long axis of mother.
- Longitudinal
- Transverse
- Oblique
- Presentation: part of baby foremost in the pelvis
- Cephalic
- Breech (bottom)
- Shoulder
- Face
- Compound:
- Head / hand -> watch (usually resolves itself; may apply a noxious stimuli to the hand)
- Head / foot-> c-section (will not resolve itself; requires c/s)
- Cord prolapse (funic presentation): an emergency.
- When the cord drops into the vagina.
- Must move quickly to c/s.
- Attitude: how the baby presents its head
- Normal attitude is folded on itself w/ flexed head
- Position: relation of presenting part to maternal pelvis anterior aspect
- When the baby presents cephalically, the reference point on the baby to be referenced to the anterior pubis of the mother is the occiput
- When the baby presents facially, the reference point is the mentum
- When the baby presents as a breech, the reference point is the sacrum
- When the baby presents transverse (shoulder), the reference point is the acromion process
Fetal Attitude
- There are a variety of ways the fetus can present at the os; these are called attitudes:
- Full flexion (A)
- Normal, smallest diameter.
- Military attitude (B)
- Brow presentation (C)
- Face presentation (D)
- Full flexion (A)
- Leopold’s Maneuver can be used to determine the attitude of the fetus.
- First maneuver: what is occupying the fundus?
- Soft like a butt or hard like a head?
- Second maneuver: on which side is the fetal spine?
- Third maneuver: what is presenting at the pelvis?
- Soft like a butt or hard like a head?
- Fourth maneuver: what is the attitude, based on the flexion / extension of the head?
- First maneuver: what is occupying the fundus?
- Can correlate with CT if there is any questions.
Vaginal Exam
- We are trying to determine if the cervix is starting to dilate or efface.
- We describe effacement as a percent of normal length:
- Normal length of a cervix is 4cm.
- So if the cervix is observed as being 2 cm effaced, we call it 50%.
- Station: the lowest point of the fetus in reference to the ischial spines.
- The stating is described as -1 (and so on, for every centimeter) it is above the ischial spines.
- The station is described as +1 (and so on, for every centimeter) it is below the ischial spines.
- Position:
- Most common is cephalic.
- Use the occiput as the baby reference point when describing position against the maternal anterior pubis.
- "right" and "left" shifts describe maternal right and left
- To determine which aspect is the occiput, recall there are ant and post fontanelles (along which to orient) and the frontal suture (to identify the anterior aspect of the baby).
- Pelvimetry:
- Performed at the first pre-natal visit and upon admission for L&D.
- Describes adequacy of the pelvis for baby delivery.
- Measures pelvic inlet, the midpelvis, and the pelvic outlet.
Pelvic Inlet
- True pelvic inlet measurement is from superior pubic ramus to the sacral prominence.
- However, this can't be measured directly so we measure it indirectly.
- True conjugate is also called the obstetric conjugate.
- The diagonal conjugate is measured with one's third finger, along toward the thumb.
- True obstetric conjugate = diagonal conjugate – 1.5 to 2.0 cm
- Diagonal conjugate: >11.5 cm is adequate
Midpelvis
- Sacrum – hallow versus shallow (flat):
- Hallow is concave like a bowl of soup and gives more room for baby moving.
- Ischial spines – blunt vs. prominent
- blunt is better; more room
- Pelvic sidewalls
- Parallel = OK
- Divergent = good
- Convergent = bad
Pelvic Outlet
- Bituberous diameter:
- > 6-8 cm is good
- Measured by placing fist up against the butt.
- Pubic arch:
- > 90 degrees is good
Stages of Labor
- 1st Stage: beginning of cervical dilation to complete dilation (10 cm)
- 2nd Stage: complete dilation to delivery of fetus
- 3rd Stage: delivery of placenta
- up to 30 minutes
- 4th Stage: first hour after delivery of placenta
- Big fluid shift, high risk of post-partum hemorrhage.
- Monitoring mom for vitals
- Monitoring firmness of uterus (should remain firm to inhibit hemorrhage by pressing layers of endometrium together)
Cardinal Movements of Labor=
- Engagement
- Flexion (of the head)
- Descent
- Internal rotation
- Extension
- External rotation
- Expulsion
- If the face is anterior, it can still extend.
- If mentum-posterior, there can be no extension, so it cannot deliver.
Labor Curve
- The first phase of minimal cervical change is latent phase.
- Minutes, hours, days!
- Active phase
- > 1 cm change / hour
- Baby will move from -5cm station to 0 to +5 as it delivers.
Prolonged / Arrested Labor
- When labor isn't moving along, consider your 3 Ps
- Power: uterine contractions
- Are they strong enough?
- Give oxytocin?
- Pelvis: adequate?
- Do your pelvimetry to make sure pathway is sufficient
- Passenger: EFW, position / attitude
- Is the baby too big?
- Is the position wrong? (occiput posterior)
- Is the attitude wrong? (military)
Dysfunctional Labor
Pattern | Nullip | Multip | Rx | ||||
---|---|---|---|---|---|---|---|
Prolonged latent phase | >20 hr | >14 hr | Rest, AROM (augmented rupture of membranes; helps augment maternal environment for labor), Pitocin (oxytocin) | ||||
Protracted dilation | <1.2 cm/hr | <1.5 cm/hr | AROM, Pit | ||||
Protracted descent | <1 cm/hr | <2 cm/hr | Pit | Arrest of dilation | >2 hr | >2 hr | AROM, Pit, C/S |
Arrest of descent | >2 hr | >1 hr | Vacuum, forceps, C/S |
Cesarean Section
- History
- Caedere -> caesura: to cut; seco: to cut.
- "Cut Cut"
- Francois Rousset (1581)
- First reported case with survival.
- Questionable
- Max Sanger (1882)- Leipzig
- Work on the American frontier
- Sewed the womb shut! (Whoa!)
- Crazy b/c the womb was considered an awful, evil thing, that shouldn't be sewn shut b/c all those bad humors would stay inside!
- Most common surgical procedure
- 1965: <5%, 1996: 20.7%, 2004: 29.1%
- No change in cerebral palsy rate
C-section - Techniques
- Uterine Incisions
- Low transverse
- The most common way because it runs with the grain of the muscular fibers.
- Also, this area does less labor contracting so next pregnancy is less likely to result in rupture.
- Low verticle
- Classical
- Kerr
C-section - Indications
Fetal C-section Indications
- Distress / intolerance of labor
- FHT of category 2 or 3
- Malpresentation (breech, transverse)
- Twins, multiples
- Vertex / Vertex = allow to labor
- Some congenital anomalies
- NTD
Maternal-Fetal C-section Indications
- Arrest of active labor
- Pretty common
- Failed induction of labor (?)
- Placenta previa, vasa previa
- When the placenta covers the cervical os.
- When the placental vessels course between baby and os.
- 50% mortality post-rupture!
- Active HSV outbreak
- HIV+ (viral load >1000/ml)
- If mom is on ARV therapy, there is no decrease in transmission with c/s.
- EFW > 4500 - 5000 grams (increasing risk of shoulder dystocia)
- Use u/s to estimate weight.
Maternal C-section Indications
- Obstructive tumors (some leiomyomas)
- Severe condylomata acuminata
- Cervical cancer
- Abdominal cerclage
- Prior c-section
- Risk of uterine rupture is 0.5-1%
- Can be catastrophic
- Prior vaginal colporrhaphy
- Vaginal delivery contraindicated medically
- Pregnant???
- No!
C-section - Risks
- At time of surgery / Immediate post-op
- Infection: endometritis, wound infection, septic pelvic thrombophlebitis (SPT)
- Bleeding: transfusion, hysterectomy
- Damage to fetus
- Very small; no larger than with vaginal delivery.
- Damage to adjacent organs
- Subsequent pregnancy:
- Adhesions
- Uterine rupture
- Placenta previa (when the placenta covers the os) may convert to accreta (when the placenta invades the myometrium).
- Accreta carries huge risks because there is often massive bleeding.
- Accreta puts the mother a risk of death.
- That is, placenta previa with a previous c/s has a very high risk of being bad!
- 0 –> 5% (number of previous c/s, risk of accreta given a placenta previa)
- 1 –> 24%
- 2 –> 48%
- 3 –> 67%
There will be a test question on prior c/s and placenta previa.
Operative Vaginal Delivery
- Forceps and vacuum can be used to guide the baby's head out of the pelvis.
- There are many different types and procedures.
Operative Vaginal Delivery - Classification
- We want, first, to be sure the baby has reached the pelvic inlet.
- Didn't talk about any of this:
- Outlet: scalp visible at introitus w/out separating labia; no rotation
- Low: leading point of skull at or below +2 cm station
- Rotate < 45°
- Rotate > 45°
- Mid: above +2 cm station but engaged
Operative Vaginal Delivery - Indications
- Nonreassuring FHT’s
- Prolonged 2nd stage of labor
- Shortened 2nd stage if pushing / Valsalva not indicated
- Maternal exhaustion
Operative Vaginal Delivery - Prerequisites
- Cervix completely dilated
- Ruptured membranes
- Fetal skull engaged in pelvis
- Empty bladder
- Position! Position! Position!
- Before we put anything on the baby's head, we have to know the position so we don't break the nasal bone or deform the child.
- Adequate pelvis
- Adequate anesthesia
Operative Vaginal Delivery - Forceps Assisted
- Use the same angles when applying traction.
- Apply the extension just like in a non-operative vaginal delivery.
Operative Vaginal Delivery - Risks
- Maternal:
- Vaginal / perineal trauma, damage to rectal sphincter
- Mostly forceps issues with mom
- Fetal:
- Mostly vacuum issues with baby
- Cephalohematoma
- Subgaleal hemorrhage
- Bony facial trauma
- Facial nerve injury
- Intraventricular hemorrhage
Birth Trauma
- Caput succedaneum:
- Very common
- Crosses midline
- Subgaleal hemorrhage:
- Does not cross midline
- Rare
- Hypovolemia and DIC
Common Post Partum Problems
- PP Hemorrhage: >500cc (>1000cc for c/s):
- Atony
- When the uterus won't contract.
- Linings aren't collapsed together to stop bleeding.
- Lacerations (cervix, vagina, perineum)
- Retained placenta
- Keeps the endometrium layers from coapting (collapsing together).
- Uterine rupture
- Uterine inversion
- Amniotic fluid embolism
- Atony
- Endometritis:
- Fundal tenderness w/ temperature >38°C x 2 or >38.5°C
- Polymicrobial infection
- More common after c/s
- Prolonged ruptured membranes
- Chorioamnionitis
- Treat with broad spectrum antibiotics
PP / Post-Op Fever
- Causes and symptoms
- Wind (atelectasis, pneumonia)
- Wound (seroma, necrotizing fasciitis)
- Water (UTI)
- Walk (thrmobophlebitis)
- Wonder drug (drug reaction)
- Womb (endometriosis)
- Wean (mastitis, engorgement)