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, | *Can be triggered by infections, stress, hypertension, uncontrolled DM | ||
==Clinical | ==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) | ||
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{{VB DDX greater than 20}} | {{VB DDX greater than 20}} | ||
== | ==Evaluation== | ||
*Do NOT perform digital exam in patients who present with vaginal bleeding when >20 weeks pregnant | *Do NOT perform digital exam in patients who present with vaginal bleeding when >20 weeks pregnant | ||
*Start with ultrasound to assess position of cervix and | *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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*U/S to assess placental position / fetal position | *U/S to assess placental position / fetal position | ||
*Digital exam to assess cervical thickness, effacement, rupture of membranes | *Digital exam to assess cervical thickness, effacement, rupture of membranes | ||
*Type and Screen, CBC, Chem 10, Coags, U/A | *Type and Screen, CBC, Chem 10, Coags, U/A with culture, Utox (cocaine increases risk of abruption) | ||
===Cervical length=== | ===Cervical length=== | ||
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*<34 weeks | *<34 weeks | ||
**Hospitalization | **Hospitalization | ||
**Betamethasone | **Betamethasone 12mg IM q24hrs x2 doses | ||
**Tocolytics (see below for options/dosages) | **Tocolytics (see below for options/dosages) | ||
**Antibiotics for GBS prophylaxis if status unknown | **Antibiotics for GBS prophylaxis if status unknown | ||
**Other | **Other antibiotics only indicated in setting of active infection | ||
===Tocolysis=== | ===Tocolysis=== | ||
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**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 | **Delay in delivery for treatment of reversible condition possibly triggering labor (UTI/pyelo) | ||
***Betamethasone requires | ***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 | ||
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*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 | ||
**[[Nifedipine]] 20mg x1, additional 20mg dose in 90min if ctx persist, followed by 20mg q3-8 hrs | **[[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 | **[[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, | *If cervix >30mm, contractions have stopped, consider 6 hours of obs | ||
==See Also== | ==See Also== |
Revision as of 07:53, 7 July 2017
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)
- Emergent delivery
- Placental abruption
- Placenta previa
- Vasa previa
- Uterine rupture
- Preterm labor
- Vaginal trauma
- Placenta accreta
- Intrauterine fetal demise
Evaluation
- Do NOT perform digital exam in patients who present with vaginal bleeding when >20 weeks pregnant
- 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, ABCs
- Fetal Heart Monitor
- U/S to assess placental position / fetal position
- Digital exam to assess cervical thickness, effacement, rupture of membranes
- Type and Screen, CBC, Chem 10, Coags, U/A with culture, Utox (cocaine increases risk of abruption)
Cervical length
- >30mm - Labor less likely
- Observation of 6 hours might be appropriate
- 20-30mm - Increased risk for preterm labor
- Fetal fibernetin result can assist, if over 50ng/ml manage labor actively
- <20mm - labor very likely
- Manage actively
Management by Weeks
- 24-32 weeks
- Mag sulfate (neuroprotection against cerebral palsy)
- <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
- Intratuterine fetal demise / lethal anomaly
- Maternal hemorrhage or instability
- Intraamniotic infection
- Severe preeclampsia or eclampsia
- Nonreassuring fetal status
- Contraindications to the drugs
- Medications
- Indomethacin 50-100mg loading dose, 25mg q4-6 hrs for 48 hrs
- 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
- ↑ Nitrazine Test. https://www.pathology.med.umich.edu/poc/onsite/pH-amniotic.html
- UpToDate "Overview of preterm labor and birth"
- UpToDate "Inhibition of acute preterm labor"