Preterm labor: Difference between revisions

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*Increased risks to child depending on age of fetus
*Increased risks to child depending on age of fetus
**Cerebral palsy, poor lung development, cognitive delay, etc
**Cerebral palsy, poor lung development, cognitive delay, etc
*Can be triggered by infections, stress, HTN, uncontrolled DM
*Can be triggered by infections, stress, hypertension, uncontrolled DM


==Clinical Presentation==
==Clinical Features==
*Similar to term labor
*Similar to term labor
*Uterine contractions q 10 min (may be irregular)
*Uterine contractions q 10 min (may be irregular)
*New onset of vaginal mucus, blood, pink discharge, amniotic fluid
*New onset of vaginal mucus, [[vaginal bleeding|blood]], pink discharge, amniotic fluid
*Low back ache, vaginal pressure
*Low [[back pain|back ache]], vaginal pressure


==Differential Diagnosis==
==Differential Diagnosis==
{{VB DDX greater than 20}}
{{VB DDX greater than 20}}


==Diagnosis==
==Evaluation==
*Do NOT perform digital exam in patients who present with vaginal bleeding when >20 weeks pregnant
*Type and Screen, CBC, Chem 10, Coags, U/A with culture, Utox (cocaine increases risk of abruption)
*Start with ultrasound to assess position of cervix and r/o placenta previa
*Do NOT perform digital exam in patients who present with vaginal bleeding when >20 weeks pregnant due to potential for placenta previa
*Start with ultrasound to assess position of cervix and rule out placenta previa
*Swabs for nitrazine, fetal fibronectin (FFN), GBS culture should also precede digital exam
*Swabs for nitrazine, fetal fibronectin (FFN), GBS culture should also precede digital exam
**Some lubricants can affect FFN and amniotic fluid pH strip
**Some lubricants can affect FFN and amniotic fluid pH strip
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==Management==
==Management==
*IV access, ABCs
*IV access x2, ABCs
*Fetal Heart Monitor
*Fetal heart monitor
*U/S to assess placental position / fetal position
*Immediate obstetrical consult
*Digital exam to assess cervical thickness, effacement, rupture of membranes
*Type and Screen, CBC, Chem 10, Coags, U/A w/ culture, Utox (cocaine increases risk of abruption)


===Cervical length===
===Cervical length===
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**Observation of 6 hours might be appropriate
**Observation of 6 hours might be appropriate
*20-30mm - Increased risk for preterm labor
*20-30mm - Increased risk for preterm labor
**Fetal fibernetin result can assist, if over 50ng/ml manage labor actively
**Fetal fibronectin result can assist, if over 50ng/ml manage labor actively
*<20mm - labor very likely
*<20mm - labor very likely
**Manage actively
**Manage actively
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===Management by Weeks===
===Management by Weeks===
*24-32 weeks
*24-32 weeks
**Mag sulfate (neuroprotection against cerebral palsy)
**[[Magnesium sulfate]] (neuroprotection against cerebral palsy)
*<34 weeks
*<34 weeks
**Betamethasone, and hospitalization
**Hospitalization
**Tocolytics
**[[Betamethasone]] 12mg IM q24hrs x2 doses
**Antibiotics for GBS prophylaxis if status unknown
**Tocolytics (see below for options/dosages)
**Other abx only indicated in setting of active infx
**[[Antibiotics]] for GBS prophylaxis if status unknown
**Other antibiotics only indicated in setting of active infection


===Tocolysis===
===Tocolysis===
*Indications
====Indications====
**Only if fetus would benefit from delay in delivery of 48 hrs
*Only if fetus would benefit from delay in delivery of 48 hrs
**Gestational age 22wks - 34 wks
*Gestational age 22wks - 34 wks
**Transport to facility for definitive delivery
*Transport to facility for definitive delivery
**Delay in delivery for tx of reversible condition possibly triggering labor (UTI/pyelo)
*Delay in delivery for treatment of reversible condition possibly triggering labor (UTI/pyelo)
***Betamethasone requires approx 48 hrs for maximal benefit for lung maturity, reducing intraventricular hemorrhage, NEC, and death
**Betamethasone requires approximately 48 hrs for maximal benefit for lung maturity, reducing intraventricular hemorrhage, NEC, and death
***Tocolysis rarely effective for longer than 48 hrs
**Tocolysis rarely effective for longer than 48 hrs
***Does not remove underlying cause for tocolysis
**Does not remove underlying cause for tocolysis


*Contraindications  
====Contraindications====
**Intratuterine fetal demise / lethal anomaly
*Intrauterine fetal demise / lethal anomaly
**Maternal hemorrhage or instability
*Maternal [[vaginal bleeding in pregnancy (greater than 20wks)|hemorrhage]] or instability
**Intraamniotic infx
*[[chorioamnionitis|Intraamniotic infection]]
**Severe preeclampsia or eclampsia
*Severe [[preeclampsia]] or [[eclampsia]]
**Nonreassuring fetal status
*Nonreassuring fetal status
**Contraindications to the drugs
*Contraindications to the drugs


*Medications
====Medications====
**[[Indomethacin]] 50-100mg loading dose, 25mg q4-6 hrs for 48 hrs
*[[Indomethacin]] 50-100mg loading dose, 25mg q4-6 hrs for 48 hrs. (avoid in gestation >32 weeks for concern of premature narrowing or closure of the ductus arteriosus)
**[[Nifedipine]] 20mg x1, additional 20mg dose in 90min if ctx persist, followed by 20mg q3-8 hrs prn ctx
*[[Nifedipine]] 20mg x1, additional 20mg dose in 90min if ctx persist, followed by 20mg q3-8 hrs PRN ctx
**[[Terbutaline]] 0.25mg sq q20-30 min up to 4 doses prn ctx
*[[Terbutaline]] 0.25mg sq q20-30 min up to 4 doses PRN ctx


==Disposition==
==Disposition==
*Admission to OB floor for delivery, or transfer to facility to manage delivery
*Admission to OB floor for delivery, or transfer to facility to manage delivery
*If cervix >30mm, ctx have stopped, consider 6 hours of obs
*If cervix >30mm, contractions have stopped, consider 6 hours of obs


==See Also==
==See Also==
*[[Vaginal Bleeding (Main)]]
*[[Vaginal Bleeding (Main)]]
*[[Pregnancy (main)]]


==External Links==


[[Category:OB/GYN]]
==External Links==


==References==
==References==
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*UpToDate "Overview of preterm labor and birth"
*UpToDate "Overview of preterm labor and birth"
*UpToDate "Inhibition of acute preterm labor"
*UpToDate "Inhibition of acute preterm labor"
[[Category:OBGYN]]

Revision as of 19:04, 15 April 2020

Background

  • Defined as labor before 37 weeks (uterine contraction and cervical change)
  • Increased risks to child depending on age of fetus
    • Cerebral palsy, poor lung development, cognitive delay, etc
  • Can be triggered by infections, stress, hypertension, uncontrolled DM

Clinical Features

  • Similar to term labor
  • Uterine contractions q 10 min (may be irregular)
  • New onset of vaginal mucus, blood, pink discharge, amniotic fluid
  • Low back ache, vaginal pressure

Differential Diagnosis

Vaginal Bleeding in Pregnancy (>20wks)

Evaluation

  • Type and Screen, CBC, Chem 10, Coags, U/A with culture, Utox (cocaine increases risk of abruption)
  • Do NOT perform digital exam in patients who present with vaginal bleeding when >20 weeks pregnant due to potential for placenta previa
  • Start with ultrasound to assess position of cervix and rule out placenta previa
  • Swabs for nitrazine, fetal fibronectin (FFN), GBS culture should also precede digital exam
    • Some lubricants can affect FFN and amniotic fluid pH strip
    • Nitrazine test (5% FP rate, 1% FN rate) - pH swab turns blue, indicating alkalotic amniotic fluid (pH 6.5 - 7.5 positive test); do not touch to mucous plug in cervix[1]
  • Proceed with digital exam if placental previa unlikely, and digital exam is urgently needed to assist patient care, such as in fetal HR decels

Management

  • IV access x2, ABCs
  • Fetal heart monitor
  • Immediate obstetrical consult

Cervical length

  • >30mm - Labor less likely
    • Observation of 6 hours might be appropriate
  • 20-30mm - Increased risk for preterm labor
    • Fetal fibronectin result can assist, if over 50ng/ml manage labor actively
  • <20mm - labor very likely
    • Manage actively

Management by Weeks

  • 24-32 weeks
  • <34 weeks
    • Hospitalization
    • Betamethasone 12mg IM q24hrs x2 doses
    • Tocolytics (see below for options/dosages)
    • Antibiotics for GBS prophylaxis if status unknown
    • Other antibiotics only indicated in setting of active infection

Tocolysis

Indications

  • Only if fetus would benefit from delay in delivery of 48 hrs
  • Gestational age 22wks - 34 wks
  • Transport to facility for definitive delivery
  • Delay in delivery for treatment of reversible condition possibly triggering labor (UTI/pyelo)
    • Betamethasone requires approximately 48 hrs for maximal benefit for lung maturity, reducing intraventricular hemorrhage, NEC, and death
    • Tocolysis rarely effective for longer than 48 hrs
    • Does not remove underlying cause for tocolysis

Contraindications

Medications

  • Indomethacin 50-100mg loading dose, 25mg q4-6 hrs for 48 hrs. (avoid in gestation >32 weeks for concern of premature narrowing or closure of the ductus arteriosus)
  • Nifedipine 20mg x1, additional 20mg dose in 90min if ctx persist, followed by 20mg q3-8 hrs PRN ctx
  • Terbutaline 0.25mg sq q20-30 min up to 4 doses PRN ctx

Disposition

  • Admission to OB floor for delivery, or transfer to facility to manage delivery
  • If cervix >30mm, contractions have stopped, consider 6 hours of obs

See Also

External Links

References

  • UpToDate "Overview of preterm labor and birth"
  • UpToDate "Inhibition of acute preterm labor"