OBGYN - Pregnancy Gone Wrong

From Iusmicm

Revision as of 00:36, 4 December 2011 by 134.68.138.157 (Talk)
(diff) ← Older revision | Current revision (diff) | Newer revision → (diff)

Contents

Pregnancy Gone Wrong

Objectives

  • Discuss classification, risk factors, and management of hypertensive disorders of pregnancy.
  • Discuss major causes of third trimester bleeding, risk factors, and management
  • Discuss preterm labor definition, risk factors, and management
  • Discuss definitions, risk factors, and management of premature rupture of membranes (PROM) and preterm premature rupture of the membranes (PPROM)

Hypertensive Disorders of Pregnancy

  • Classification of types of hypertensive disorders:
    • Chronic Hypertension
    • Gestational Hypertension
    • Preeclampsia
    • Eclampsia
    • Chronic hypertension with superimposed preeclampsia


Definitions

  • Chronic Hypertension is defined as:
    • Systolic = 140 and / or
    • Diastolic = 90
    • having existed before pregnancy and persisting more than 12 weeks postpartum


  • Gestational Hypertension is defined as:
    • Systolic = 140 and / or
    • Diastolic = 90
    • that develops after the 20th week of pregnancy
    • in a woman previously known to be normotensive


  • Preeclampsia (like gestational hypertenstion) is a type of hypertensive state that is specific to pregnancy.
    • NB: unlike gestational hypertenstion, preeclampsia requires proteinuria.
  • Preeclampsia is defined as:
    • Systolic = 140 and / or
    • Diastolic = 90
    • that develops after 20th week gestation
    • with proteinuria >= 300mg in a 24 hour urine specimen
  • Preeclampsia is classified as either mild or severe.


  • Eclampsia is defined as:
    • having one or more generalized convulsions and / or coma in the setting of preeclampsia
    • and is in the absence of other neurologic conditions


  • Chronic Hypertension with Superimposed Preeclampsia is defined as:
    • Systolic = 140 and / or
    • Diastolic = 90
    • having existed before pregnancy and persisting more than 12 weeks postpartum
    • with proteinuria >= 300mg in a 24 hour urine specimen

Chronic Hypertension

  • Recall that chronic hypertension is a BP over 140/90 that precedes and post-dates pregnancy.
  • Chronic hypertension affects >22% of women of childbearing age.
  • Chronic hypertension is a risk factor for all of the following pregnancy complications:
    • Preeclampsia (hypertension with proteinuria)
    • Fetal growth restriction
    • Abruption (premature separation of normal placenta from the uterine wall)
    • Preterm Birth


  • Chronic hypertension management:
    • Treatment is important to prevent maternal vascular complications (stroke, MI, renal failure)
    • Treatment thresholds:
      • Systolic BP >150-160mmHg
      • Diastolic BP >100-110mmHg
    • Tx goal is to be sure there is no end-organ damage:
    • Tx goal levels (without evidence that end-organ damage has already occurred):
      • Systolic 140-150mmHg
      • Diastolic 90-100mmHg
    • Tx goal levels (with evidence of end-organ damage):
      • BP < 140/90


  • Chronic hypertension tx:
    • Get a baseline 24 hour urine for protein
      • Useful for retrospection if pt presents with preeclampsia later in pregnancy
    • Fetal growth surveillance
    • Delivery at term
      • Unless mother or baby show complications
    • Pharma for HTN:
      • First line agents:
        • Beta-blockers: methyldopa, labetalol
      • Other prego-safe agents:
        • Diuretics (hctz = hydrochlorothiazide)
        • Ca channel blockers (procardia)
      • Contraindicated agents:
        • ACE inhibitors
        • ARBs
        • hydra
        • Because of fetal abnormalities

Gestational Hypertension

  • Gestational hypertension is classified as "severe" or "mild".
    • Mild HTN: > 140/90
    • Severe HTN: 160/110
  • BP should be measured twice, 6 hours apart for gestational HTN dx.
  • Gestational hypertension is a provisional diagnosis--it assumes the hypertensive state is transient and will resolve before 12 weeks postpartum.
  • The diagnosis of gestational hypertension might be modified to:
    • preeclampsia: if the pt develops proteinuria
    • chronic hypertension: if the pt does not return to normotensive within 12 weeks post-partum


  • Gestational hypertension management:
    • Same as chronic hypertension

Preeclampsia

  • Recall that preeclampsia is new-onset hypertension with proteinuria, 20+ weeks into pregnancy.
  • Like gestational hypertension, diagnosis of preeclampsia requires two BPs, 6h-7d apart that are > 140/90
  • Diagnosis of preeclampsia requires a 24hr urine protein to be >= 300mg.
  • There are two types of preeclampsia: mild and severe.


  • Mild preeclampsia:
    • BP > 140/90
    • 300mg protein in 24 h urine specimen or persistent 1+ on dip
    • 0.5% of mild preeclampsias will convert to eclampsia.


  • Severe preeclampsia:
    • BP >= 160/110
    • 5g protein in 24 h urine specimen or persisten 2+ on dip
    • With end-organ damage signs / symptoms!
      • Symptoms of CNS dysfunction: HA, blurred vision, scotomata
      • Symptoms of liver capsule distension: epigastric pain, nausea, vomiting
      • Signs of hepatocelluar injury: Elevated AST ALT twice normal
    • Oliguria (<500cc/24h)
    • Pulmonary Edema
    • Intrauterine growth restriction (fetus <10th percentile weight for GA)
    • Stroke
    • 2% of severe preeclampsias will convert to eclampsia.


  • Preeclampsia: Risk Factors:
    • Nulliparity
    • Multifetal gestation
    • Obesity
    • Age extremes (>35 or <20)
    • African American ethnicity
    • History of CHTN, renal disease, collagen vascular disease
    • History of diabetes mellitus, gestational diabetes, metabolic syndrome
    • History of previous preeclampsia


  • Preeclampsia: Management
    • The only cure for preeclampsia is delivery.
    • Mild
      • Manage expectantly until term, induce
      • Outpatient for reliable pts, inpatient for unreliable pts.
    • Severe
      • Magnesium Sulfate and Deliver!!
      • Consider expectant management for very preterm, stable patients
        • Have detailed reasoning and plan for delivery documented
        • Especially near fetal-viability grey area like 25, 26 weeks.

Eclampsia

  • �Recall that eclampsia is one or more generalized convulsions / comas with preeclampsia (HTN, proteinuria) and without an explanatory neurologic condition.
  • 2% severe preeclamptics will convert to eclampsia.
  • We don't know why the convulsions / comas occur.
  • Convulsions / comas can occur before birth, during labor, 48hr postpartum, and even 4 weeks postpartum.


  • Management of eclampsia:
    • Stabilize Mom
      • Assure airway, Oxygen
      • Magnesium sulfate (prevent seizures; also decreases contractions though that's not the point here)
      • Treat hypertension (see previously listed drugs)
    • Deliver Baby
      • Use c/s (c-section) if the mother is not close to delivering.
      • If 8cm dilated or somewhat close to delivery, vaginal delivery is an option.
        • Consider the fetal position, the cervix dilation, and the GA 
If the mother is 8cm dilated and seizing, stabilize her and deliver vaginally.


Third Trimester Bleeding

  • Third trimester bleeding is bleeding beyond the 28th week.
  • This is not bleeding just from cervical dilation or something else benign, but true, serious bleeding.
  • 3-4% of all pregnancies have complications that involve third trimester bleeding.
  • “Antepartum hemorrhage” term used for bleeding which is not related to labor or delivery.
    • Also called "sentinal bleeding".


  • Etiologies of third trimester bleeding:
    • Labor (be it term or preterm): the obvious one.
    • Abruptio placenta: placenta prematurely tears from the uterine wall
    • Placenta previa: placenta is attached over or near the os
    • Vasa previa: placental vasculature lies between the fetus and the os
    • Uterine rupture: all layers of the uterus tear

Placental Abruption

  • Premature separation of a normal placenta beyond 20 weeks
  • Classic triad:
    • bleeding
    • abdominal pain / uterine tenderness
    • contractions
  • There may or may not be changes in the fetal heart rate
  • Ultrasound only visualizes 2% of abruptions
  • A history of trauma should raise your level of suspicion for placental abruption.
  • A visible abruption is continuous with the os and therefore may have some to much bleeding.
  • A concealed abruption is not continuous with the os and therefore may have little to no bleeding.


  • Risk factors for placental abruption:
    • Hypertension
    • Prior abruption
    • Trauma
    • Smoking
    • Cocaine use
    • Uterine anomaly / fibroids
    • Multiparity
    • Advanced maternal age
    • Preterm premature rupture of membranes (PPROM)
    • Bleeding diathesis (bleeding disorders; like factor V deficiency)
    • Rapid decompression of an over-distended uterus
      • Multiple pregnancy (upon delivery of the first baby, the placenta may detach when the pressure in the uterus decreases)
      • Polyhydramnios (lots of fluid, then membranes break and there is sudden decrease in pressure; abruption)


  • Placental Abruption Management:
    • Evaluate:
      • Hemodynamic status
      • Continuous fetal monitoring
      • Labs
    • Stabilize
      • Large bore IV-crystalloid or packed red cells
    • Deliver (consider along a spectrum as to whether the mom is likely to deliver first or bleed too much first)
      • Severe abruption
        • Coagulopathy
        • Fetal compromise
      • Mode
        • Usually c/s post maternal stabilization (because the mom won't stop bleeding so we have to get the baby out)
        • Dependent upon GA fetus, maternal condition, cervical status
    • Conservative Management:
      • Mild abruption remote from term
      • "Chronic type" abruptions

Placenta Previa

  • Placenta previa is when the placenta covers or is near to the os.
  • Placenta previa in early pregnancy can change over the course of the pregnancy


  • Types of Placenta Previa:
    • Complete: covers the os
    • Partial: covers part of the os
    • Marginal: a catch all (indetermined) or the tech couldn't tell
    • "Low-lying" placenta previa:
      • Placenta previa in 2nd trimester
      • Lower uterine segment, but exact placenta / os relationship not determined
      • Edge within 2-3 cm of os


  • Uterine scarring increases the risk of placenta previa.
  • Uterine scarring may result from:
    • Increasing parity
    • Advancing maternal age
    • Number of prior c/s deliveries
    • Number of curettages


  • Management of Placenta Previa:
    • Conservative management:
      • If the mother is stable and preterm
      • Close monitoring of mom + baby
    • Deliver by C-section for:
      • Non-reassuring fetus
      • Life threatening maternal hemorrhage
      • Bleeding anytime after 34 weeks

Vasa previa

  • Vasa previa is when there are placental vessels between the fetus and the os.
  • These vessels are traversing the membranes
  • Diagnosis of vasa previa:
    • Profuse bleeding after ROM, fetal heart rate abnormalities
    • US, dopplar (shows blood flow)
  • Our concern is fetal exsanguination (bleeding to death) upon rupture of the membranes which could involve the vasa previa.


  • Vasa previa management: deliver by c/s immediately!

Uterine Rupture

  • Uterine rupture is defined as nonsurgical disruption of all uterine layers with bleeding and with / without extrusion of fetal / placental material.
  • Most babies survive with rapid dx and tx (sx).
  • Woman can get pregnant again but birth plan will have to include c/s.


  • Risk Factors for uterine rupture:
    • Previous c/s (c-sections)
    • Previous uterine surgery (other than c/s)


  • Uterine rupture clinical presentation:
    • Fetal bradycardia
    • Constant, sudden abdominal pain
    • Hypotension
    • Loss of station (floating fetus; can no longer feel the fetus at its previous location)
    • Uterine tenderness / change in shape
    • Vaginal bleeding (may be modest because blood may flow into abdomen)

Preterm Labor

  • Preterm labor is defined as regular contractions with cervical change before 37 weeks.
  • We have no answer why preterm labor occurs.
  • 12.5% births in US preterm
  • 80% of preterm births are due to preterm labor.
    • 50% strictly PTL
    • 30% PPROM
  • 20% of preterm births are due to iatrogenic induction.
  • PTB 2nd leading cause of infant mortality overall
    • PTB is 1st leading cause of infant mortality for AA


  • Risk factors include:
    • Previous preterm labor
    • Multiple gestation
    • Age extremes: adolescents, >35
    • African Americans
    • Low socioeconomic status


  • Preterm labor management:
    • Tocolysis (giving medicaiton to stop contractions)
      • Nifedipine (Ca channel blocker)
      • Magnesium Sulfate
      • Terbutaline
    • Steroids (to facilitate fetal lung maturity, 24-34 weeks)
    • Investigate for cause (like infection)
      • Treat cause if found
    • Monitor for further cervical change=
    • Monitor contractions
    • Monitor fetal heart


Premature Membrane Rupture

  • Premature rupture of membranes (PROM) is defined as rupture of the membranes without labor (contractions, etc).
  • Preterm Premature Rupture of Membranes (PPROM) is defined as rupture of the membranes without labor (contractions, etc.) before 37 weeks.

Premature Rupture of Membranes (PROM)

  • Premature rupture of membranes (PROM) is defined as rupture of the membranes without labor (contractions, etc).
  • Premature rupture of membranes occurs in 8% of pregnancies.
    • ½ deliver within 5 hours
    • 95% deliver within 28 hours
  • Recall that by definition, premature rupture of membranes occurs at term.
    • Otherwise it would be PPROM (preterm premature rupture of membranes).


  • Management of PROM (premature rupture of membranes):
    • Waiting for 24 hrs from rupture to proceed with induction of labor
    • Immediate induction of labor (oxytocin)
    • Immediate performance of a c/s in those with prior history or malpresentation
      • Because we don't want them to have contractions

Preterm Premature Rupture of Membranes (PPROM)

  • Preterm Premature Rupture of Membranes (PPROM) is defined as rupture of the membranes without labor (contractions, etc.) before 37 weeks.
  • PPROM is a rupture of the membranes before 37 weeks.
  • 75% will deliver spontaneously within 1 week


  • Risk factors for PPROM:
    • Previous PPROM
    • Infection
    • Others similar to preterm labor


  • PPROM Maternal Sequelae:
    • Chorioamnionitis (inter-uterine infection durinig pregnancy)
    • Endometritis (inter-uterine infection postpartum)
    • Bacteremia (usually secondary to choriomanionitis or endometritis)


  • PPROM Fetal Sequelae:
    • Prematurity


  • PPROM management:
    • Steroids (for fetal lung maturity)
    • Antibiotics (to prolong latency before parturition)
    • Maternal + Fetal Surveillance for:
      • Chorioamnionitis (febrile?, tender?, pain?, pus?, odoriferous discharge?)
      • Abruption (bleeding?)
    • Deliver if:
      • Any sign of infection (fever, tachycardia, uterine tenderness, foul d/c, leukocytosis)
      • Non-reassuring fetal status
      • GA is > 34 weeks or documented fetal lung maturity
Retrieved from "http://editthis.info/iusmicm/OBGYN_-_Pregnancy_Gone_Wrong"
Personal tools